Add chat thread forking

act_runner does not carry setup-ruby's PATH changes into later steps,
so without this the step runs the toolcache default Ruby (3.3.11) and
bundler cannot find the gems installed for 3.1.7.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.gitea/workflows/testflight.yml

@@ -1,52 +1,39 @@
 name: TestFlight
 
 on:
-  workflow_dispatch:
   push:
     tags:
-      - "release/ios/v*"
+      - "release/ios/v*.*.*"
 
 jobs:
   testflight:
-    runs-on: xcode
-    defaults:
-      run:
-        shell: bash
+    name: Build and upload
+    runs-on: macos-arm64
+    timeout-minutes: 90
 
     steps:
-      - name: Checkout
+      - name: Check out the release tag
         uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
 
-      - name: Setup Ruby
+      - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "3.1.7"
+          ruby-version: "3.3.11"
           bundler-cache: true
           working-directory: ios
 
       - name: Install XcodeGen
-        run: |
-          set -euo pipefail
-          if ! command -v xcodegen >/dev/null 2>&1; then
-            brew install xcodegen
-          fi
+        run: command -v xcodegen >/dev/null 2>&1 || brew install xcodegen
 
-      - name: Upload to TestFlight
+      - name: Build and upload to TestFlight
         working-directory: ios
         env:
-          HOME: /var/lib/act_runner
-          APP_STORE_CONNECT_KEY_ID: ${{ secrets.APP_STORE_CONNECT_KEY_ID }}
-          APP_STORE_CONNECT_ISSUER_ID: ${{ secrets.APP_STORE_CONNECT_ISSUER_ID }}
-          APP_STORE_CONNECT_KEY_CONTENT: ${{ secrets.APP_STORE_CONNECT_KEY_CONTENT }}
+          ASC_KEY_ID: ${{ secrets.ASC_KEY_ID }}
+          ASC_ISSUER_ID: ${{ secrets.ASC_ISSUER_ID }}
+          ASC_KEY: ${{ secrets.ASC_KEY }}
           MATCH_PASSWORD: ${{ secrets.MATCH_PASSWORD }}
-          MATCH_GIT_URL: ${{ secrets.MATCH_GIT_URL }}
           MATCH_GIT_BASIC_AUTHORIZATION: ${{ secrets.MATCH_GIT_BASIC_AUTHORIZATION }}
-          SYBIL_BUILD_NUMBER: ${{ github.run_number }}
+          CI: "true"
           FASTLANE_SKIP_UPDATE_CHECK: "1"
-          FASTLANE_XCODEBUILD_SETTINGS_TIMEOUT: "120"
-        run: |
-          export PATH="/Users/runner/hostedtoolcache/Ruby/3.1.7/arm64/bin:${PATH}"
-          ruby --version
-          bundle exec fastlane ios beta
+          FASTLANE_HIDE_CHANGELOG: "1"
+        run: bundle exec fastlane ios beta

dist/default.conf

@@ -12,17 +12,43 @@ server {
   location /api/ {
     proxy_pass http://server:8787/;
     proxy_http_version 1.1;
+    proxy_buffering off;
+    proxy_cache off;
+    proxy_read_timeout 3600s;
+    proxy_send_timeout 3600s;
     proxy_set_header Host $host;
     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
     proxy_set_header X-Forwarded-Proto $scheme;
+    proxy_set_header Connection "";
+  }
+
+  location = /sw.js {
+    add_header Cache-Control "no-store, no-cache, must-revalidate" always;
+    expires -1;
+    try_files $uri =404;
   }
 
   location = /manifest.webmanifest {
     default_type application/manifest+json;
+    add_header Cache-Control "no-store, no-cache, must-revalidate" always;
+    expires -1;
+    try_files $uri =404;
+  }
+
+  location = /index.html {
+    add_header Cache-Control "no-store, no-cache, must-revalidate" always;
+    expires -1;
+    try_files $uri =404;
+  }
+
+  location /assets/ {
+    add_header Cache-Control "public, max-age=31536000, immutable" always;
     try_files $uri =404;
   }
 
   location / {
+    add_header Cache-Control "no-store, no-cache, must-revalidate" always;
+    expires -1;
     try_files $uri $uri/ /index.html;
   }
 }

docker-compose.example.yml

@@ -12,10 +12,12 @@ services:
       OPENAI_API_KEY: ${OPENAI_API_KEY:-}
       ANTHROPIC_API_KEY: ${ANTHROPIC_API_KEY:-}
       XAI_API_KEY: ${XAI_API_KEY:-}
+      GEMINI_API_KEY: ${GEMINI_API_KEY:-}
       HERMES_AGENT_API_BASE_URL: ${HERMES_AGENT_API_BASE_URL:-http://127.0.0.1:8642/v1}
       HERMES_AGENT_API_KEY: ${HERMES_AGENT_API_KEY:-}
       HERMES_AGENT_MODEL: ${HERMES_AGENT_MODEL:-}
       EXA_API_KEY: ${EXA_API_KEY:-}
+      BRAVE_SEARCH_API_KEY: ${BRAVE_SEARCH_API_KEY:-}
       CHAT_WEB_SEARCH_ENGINE: ${CHAT_WEB_SEARCH_ENGINE:-exa}
       SEARXNG_BASE_URL: ${SEARXNG_BASE_URL:-}
       CHAT_MAX_TOOL_ROUNDS: ${CHAT_MAX_TOOL_ROUNDS:-100}

docs/api/rest.md

@@ -34,11 +34,13 @@ Chat upload limits:
     "openai": { "models": ["gpt-4.1-mini"], "loadedAt": "2026-02-14T00:00:00.000Z", "error": null },
     "anthropic": { "models": ["claude-3-5-sonnet-latest"], "loadedAt": null, "error": null },
     "xai": { "models": ["grok-3-mini"], "loadedAt": null, "error": null },
+    "gemini": { "models": ["gemini-3.5-flash"], "loadedAt": null, "error": null },
     "hermes-agent": { "models": ["hermes-agent"], "loadedAt": null, "error": null }
   }
 }
 ```
 - OpenAI model lists are filtered to models that are expected to work with the backend's Responses API implementation.
+- Gemini model lists are loaded from Google's native Models API and filtered to Gemini `generateContent` model ids.
 - `hermes-agent` is included only when `HERMES_AGENT_API_KEY` is configured. Set it to Hermes `API_SERVER_KEY`, or any non-empty value if that local server does not require auth. `HERMES_AGENT_API_BASE_URL` defaults to `http://127.0.0.1:8642/v1`; set `HERMES_AGENT_MODEL` only when you need an additional fallback/override model id.
 - The backend loads provider model lists at startup and refreshes them about once every 24 hours. If a later provider refresh fails, the response keeps the last loaded model list for that provider and sets `error` to the latest failure message.
 
@@ -56,7 +58,7 @@ Chat upload limits:
 ```
 
 Behavior notes:
-- Lists Sybil-managed chat tools that can be enabled for `openai`, `anthropic`, and `xai` chat completions.
+- Lists Sybil-managed chat tools that can be enabled for `openai`, `anthropic`, `xai`, and `gemini` chat completions.
 - Optional tools such as `codex_exec` and `shell_exec` appear only when enabled by server environment configuration.
 
 ## Active Runs
@@ -87,6 +89,8 @@ Behavior notes:
       "type": "chat",
       "id": "chat-id",
       "title": "optional title",
+      "parentChatId": null,
+      "titleGenerationPending": false,
       "createdAt": "2026-02-14T00:00:00.000Z",
       "updatedAt": "2026-02-14T00:00:00.000Z",
       "starred": true,
@@ -115,7 +119,8 @@ Behavior notes:
 Behavior notes:
 - This endpoint is intended for combined conversation/search lists such as sidebars.
 - The legacy `GET /v1/chats` and `GET /v1/searches` endpoints remain available for clients that need separate collections.
-- The response currently combines up to 100 chats and up to 100 searches.
+- The response currently combines the 100 most recently updated chats, any additional root chats needed to group those forks, and up to 100 searches.
+- Root chats have `parentChatId: null`. Every fork points directly to its single root chat, including a fork created from another fork, so clients can group rows without traversing a fork chain.
 - `starred`/`starredAt` are backed by membership in a reserved `Project` with id `starred`; future project folders can reuse the same project item model.
 
 ## Chats
@@ -128,7 +133,7 @@ Behavior notes:
 ```json
 {
   "title": "optional title",
-  "provider": "optional openai|anthropic|xai|hermes-agent",
+  "provider": "optional openai|anthropic|xai|gemini|hermes-agent",
   "model": "optional model id",
   "additionalSystemPrompt": "optional stored system prompt",
   "enabledTools": ["web_search", "fetch_url"],
@@ -146,15 +151,32 @@ Behavior notes:
 
 Behavior notes:
 - `provider` and `model` must be supplied together when present.
+- Newly created non-fork chats have `parentChatId: null` and `titleGenerationPending: false`.
 - When `provider`/`model` are supplied, the new chat initializes `initiatedProvider`/`initiatedModel` and `lastUsedProvider`/`lastUsedModel`.
 - `additionalSystemPrompt` is trimmed and stored on the chat; blank values are stored as `null`.
 - `enabledTools` stores the enabled Sybil-managed tool names for future chat completions. Unknown tool names are ignored; omitted values default to all currently available tools.
 - Optional `messages` are inserted as the initial transcript. Attachment metadata uses the same schema and limits as chat completion messages.
 
+### `POST /v1/chats/:chatId/fork`
+- Body: `{ "messageId"?: string }`
+- Response: `{ "chat": ChatSummary }`
+- Source chat not found: `404 { "message": "chat not found" }`
+- Supplied message missing from the source chat: `404 { "message": "message not found in chat" }`
+- Supplied message is not an assistant response: `400 { "message": "fork message must be an assistant response" }`
+
+Behavior notes:
+- With no `messageId`, the server copies the complete source transcript. With an assistant response `messageId`, it copies the transcript through that response, inclusive.
+- The source chat is unchanged. Copied messages receive new ids while retaining their role, content, name, creation time, order, and metadata except for the source request's transport-only `clientRequestId`. Attachments and tool-call metadata are retained. LLM call logs, star/project memberships, and other child threads are not copied.
+- The fork inherits the source chat's user, initiated/last-used provider and model, additional system prompt, and enabled tool settings.
+- A fork of a root or another fork always sets `parentChatId` to the single root chat id. Root chats keep `parentChatId: null`.
+- A whole-chat fork starts with `Fork of <source title>` (or `Fork of Untitled chat`). A message fork starts with `Fork of '<message snippet>'`.
+- The placeholder title is returned with `titleGenerationPending: true`. After the first new prompt, call `POST /v1/chats/title/suggest`; the placeholder is eligible for replacement exactly once.
+
 ### `PATCH /v1/chats/:chatId`
 - Body: any subset of `{ "title": string, "additionalSystemPrompt": string|null, "enabledTools": string[] }`
 - Response: `{ "chat": ChatSummary }`
 - Blank titles are rejected. The server trims surrounding whitespace before storing the title.
+- Setting a title clears `titleGenerationPending`, preventing an in-flight or later automatic suggestion from replacing the manual title.
 - `additionalSystemPrompt: null` clears the stored prompt. Blank string values are also stored as `null`.
 - `enabledTools: []` disables Sybil-managed tools for this chat. Omitted settings are left unchanged.
 - Updating chat fields changes the returned chat's `updatedAt`.
@@ -181,13 +203,19 @@ Behavior notes:
 - Response: `{ "chat": ChatSummary }`
 
 Behavior notes:
-- If the chat already has a non-empty title, server returns the existing chat unchanged.
+- If the chat already has a non-empty title and `titleGenerationPending` is false, server returns the existing chat unchanged.
+- A fork placeholder with `titleGenerationPending: true` is eligible for the same title-generation flow as an untitled original chat. A successful or fallback suggestion clears the flag.
 - If a title is set while suggestion generation is in flight, server returns the current chat instead of overwriting that title.
-- When no title exists at write time, server uses OpenAI `gpt-4.1-mini` to generate a one-line title (up to ~4 words), updates the chat title, and returns the updated chat.
+- For an eligible untitled chat or pending fork placeholder, server uses OpenAI `gpt-4.1-mini` to generate a one-line title (up to ~4 words), updates the chat title, and returns the updated chat.
+- If the title provider is unavailable or rejects the request, server still persists a deterministic title derived from the first line of `content` instead of leaving the chat untitled.
 
 ### `DELETE /v1/chats/:chatId`
 - Response: `{ "deleted": true }`
 - Not found: `404 { "message": "chat not found" }`
+- Active chat or fork: `409 { "message": "chat or fork has an active stream" }`
+- Concurrent family deletion: `409 { "message": "chat family deletion already in progress" }`
+- Deleting a root chat also deletes its grouped forks. Deleting a fork leaves the root and sibling forks unchanged.
+- A root cannot be deleted while it or any grouped fork has an active completion stream. A fork cannot be deleted while its own completion stream is active.
 
 ### `GET /v1/chats/:chatId`
 - Response: `{ "chat": ChatDetail }`
@@ -234,7 +262,7 @@ Notes:
 ```json
 {
   "chatId": "optional-chat-id",
-  "provider": "openai|anthropic|xai|hermes-agent",
+  "provider": "openai|anthropic|xai|gemini|hermes-agent",
   "model": "string",
   "messages": [
     {
@@ -294,13 +322,16 @@ Behavior notes:
 - For `openai`, backend calls OpenAI's Responses API and enables internal tool use with an internal system instruction.
 - For `anthropic`, backend calls Anthropic's Messages API and enables internal tool use with Anthropic `tool_use`/`tool_result` content blocks.
 - For `xai`, backend calls xAI's OpenAI-compatible Chat Completions API and enables internal tool use with the same internal system instruction.
+- For `gemini`, backend calls Google's native Gemini `generateContent` API and enables internal tool use with Gemini function calling.
 - For `hermes-agent`, backend calls the configured Hermes Agent OpenAI-compatible Chat Completions API without adding Sybil-managed tool definitions; Hermes Agent handles its own tools server-side.
 - For `openai`, image attachments are sent as Responses `input_image` items and text attachments are sent as `input_text` items.
+- For `gemini`, image attachments are sent as native Gemini `inlineData` parts and text attachments are sent as text parts.
 - For `xai` and `hermes-agent`, image attachments are sent as Chat Completions content parts alongside text.
 - For `openai`, Responses calls that can enter the server-managed tool loop use `store: true` so reasoning and function-call items can be passed between tool rounds.
 - For `anthropic`, image attachments are sent as Messages API `image` blocks using base64 source data; text attachments are added as `text` blocks.
-- Available Sybil-managed tool calls for `openai`, `anthropic`, and `xai`: `web_search` and `fetch_url`. When `CHAT_CODEX_TOOL_ENABLED=true`, `codex_exec` is also available. When `CHAT_SHELL_TOOL_ENABLED=true`, `shell_exec` is also available.
-- `web_search` returns ranked results with per-result summaries/snippets. Its backend engine is selected by `CHAT_WEB_SEARCH_ENGINE` (`exa` default, or `searxng` with `SEARXNG_BASE_URL` set). SearXNG mode requires the instance to allow `format=json`.
+- Available Sybil-managed tool calls for `openai`, `anthropic`, `xai`, and `gemini`: `web_search` and `fetch_url`. When `CHAT_CODEX_TOOL_ENABLED=true`, `codex_exec` is also available. When `CHAT_SHELL_TOOL_ENABLED=true`, `shell_exec` is also available.
+- `web_search` returns ranked results with per-result summaries/snippets. Its backend engine is selected by `CHAT_WEB_SEARCH_ENGINE`: `exa` (default), `brave` (requires `BRAVE_SEARCH_API_KEY`), or `searxng` (requires `SEARXNG_BASE_URL`; the instance must allow `format=json`).
+- Brave searches are queued and evenly paced according to the shortest window in Brave's `X-RateLimit-Policy` response header. The backend also honors `X-RateLimit-Remaining`/`X-RateLimit-Reset` and retries `429` responses up to three times with reset-aware exponential backoff; quota resets beyond the bounded retry window fail immediately.
 - `fetch_url` fetches a URL with browser-like navigation headers and returns plaintext page content (HTML converted to text server-side).
 - `codex_exec` delegates coding, shell, repository inspection, and other complex software tasks to a persistent remote Codex CLI workspace over SSH. The server runs `codex exec --dangerously-bypass-approvals-and-sandbox --skip-git-repo-check <non-interactive wrapped prompt>` on the configured devbox inside `CHAT_CODEX_REMOTE_WORKDIR`, with SSH stdin closed.
 - `shell_exec` runs arbitrary non-interactive shell commands on the same configured devbox, starting in `CHAT_CODEX_REMOTE_WORKDIR`. It uses `bash -lc` when bash exists, otherwise `sh -lc`, closes SSH stdin, and does not run inside the Sybil server container.
@@ -318,6 +349,16 @@ Behavior notes:
   - `CHAT_SHELL_EXEC_TIMEOUT_MS=120000` (optional)
 - When a tool call is executed, backend stores a chat `Message` with `role: "tool"` and tool metadata (`metadata.kind = "tool_call"`). Streaming requests emit an initiated SSE `tool_call` event before execution, then persist each completed or failed tool call as its terminal SSE `tool_call` event is emitted, then store the assistant output when the completion finishes.
 
+## Streaming Chat
+
+### `POST /v1/chat-completions/stream`
+
+- The request accepts the chat-completion fields above plus optional `persist` and `clientRequestId` fields.
+- `clientRequestId` is only valid for a persisted request with a `chatId`, may be up to 128 characters, and should be a stable unique value generated once per user submission.
+- Retrying with the same `chatId` and `clientRequestId` replays the matching active or completed stream rather than starting a duplicate provider call.
+- The server persists the ID in `metadata.clientRequestId` on the submitted user message and completed assistant message.
+- The complete request, SSE event, persistence, retry, and attach contracts are defined in `docs/api/streaming-chat.md`.
+
 ## Searches
 
 ### `GET /v1/searches`
@@ -413,13 +454,15 @@ Behavior notes:
 {
   "id": "...",
   "title": null,
+  "parentChatId": null,
+  "titleGenerationPending": false,
   "createdAt": "...",
   "updatedAt": "...",
   "starred": false,
   "starredAt": null,
-  "initiatedProvider": "openai|anthropic|xai|hermes-agent|null",
+  "initiatedProvider": "openai|anthropic|xai|gemini|hermes-agent|null",
   "initiatedModel": "string|null",
-  "lastUsedProvider": "openai|anthropic|xai|hermes-agent|null",
+  "lastUsedProvider": "openai|anthropic|xai|gemini|hermes-agent|null",
   "lastUsedModel": "string|null",
   "additionalSystemPrompt": null,
   "enabledTools": ["web_search", "fetch_url"]
@@ -465,13 +508,15 @@ Behavior notes:
 {
   "id": "...",
   "title": null,
+  "parentChatId": null,
+  "titleGenerationPending": false,
   "createdAt": "...",
   "updatedAt": "...",
   "starred": false,
   "starredAt": null,
-  "initiatedProvider": "openai|anthropic|xai|hermes-agent|null",
+  "initiatedProvider": "openai|anthropic|xai|gemini|hermes-agent|null",
   "initiatedModel": "string|null",
-  "lastUsedProvider": "openai|anthropic|xai|hermes-agent|null",
+  "lastUsedProvider": "openai|anthropic|xai|gemini|hermes-agent|null",
   "lastUsedModel": "string|null",
   "additionalSystemPrompt": null,
   "enabledTools": ["web_search", "fetch_url"],

docs/api/streaming-chat.md

@@ -21,7 +21,8 @@ Authentication:
 {
   "chatId": "optional-chat-id",
   "persist": true,
-  "provider": "openai|anthropic|xai|hermes-agent",
+  "clientRequestId": "optional-client-generated-id",
+  "provider": "openai|anthropic|xai|gemini|hermes-agent",
   "model": "string",
   "messages": [
     {
@@ -61,6 +62,9 @@ Notes:
 - If `persist` is `true` and `chatId` is omitted, backend creates a new chat.
 - If `chatId` is provided, backend validates it exists.
 - If `persist` is `false`, `chatId` must be omitted. Backend does not create a chat and does not persist input messages, tool-call messages, assistant output, or `LlmCall` metadata.
+- `clientRequestId` is optional and is only valid for a persisted stream with a `chatId`. Clients should generate one stable, unique value per user submission and reuse it when retrying a disconnected request.
+- A retry with the same `chatId` and `clientRequestId` attaches to and replays the matching active stream. If that submission already completed, the endpoint replays `meta` and `done` without invoking the provider again. This makes retrying the initial streaming `POST` idempotent.
+- `clientRequestId` values may be up to 128 characters. The server stores the value in `metadata.clientRequestId` on the submitted user message and completed assistant message.
 - For persisted streams, backend stores only new non-assistant input history rows to avoid duplicates.
 - `additionalSystemPrompt`, when present directly or loaded from stored chat settings, is prepended to the provider request as a `system` message and is not inserted into the persisted chat transcript by this endpoint.
 - `enabledTools` limits Sybil-managed tools for this request. When omitted for a saved chat, the stored chat setting is used; otherwise all available tools are enabled by default. An empty array disables Sybil-managed tools.
@@ -69,8 +73,10 @@ Notes:
 
 Persisted chat streams with a `chatId` are backend-owned active runs:
 - Once started, the backend keeps the stream running even if the HTTP client disconnects or refreshes.
+- The backend reserves the active run before persisting submitted messages, preventing a root or fork deletion from interleaving with stream setup.
 - While running, `GET /v1/active-runs` includes the `chatId`.
-- Starting a second persisted stream for the same active `chatId` returns `409`.
+- Starting a second persisted stream for the same active `chatId` returns `409`, unless its `clientRequestId` matches the active submission, in which case the existing stream is replayed.
+- Starting a persisted stream while that chat family is being deleted returns `409 { "message": "chat family deletion already in progress" }`.
 - Clients can reattach with `POST /v1/chats/:chatId/stream/attach`.
 
 ## Attach Endpoint
@@ -174,18 +180,21 @@ Terminal tool-call event:
 - `openai`: backend uses OpenAI's Responses API and may execute internal function tool calls (`web_search`, `fetch_url`, optional `codex_exec`, and optional `shell_exec`) before producing final text.
 - `anthropic`: backend uses Anthropic's Messages API and may execute the same internal tools with `tool_use`/`tool_result` content blocks before producing final text.
 - `xai`: backend uses xAI's OpenAI-compatible Chat Completions API and may execute the same internal tool calls before producing final text.
+- `gemini`: backend uses Google's native Gemini `streamGenerateContent` API and may execute the same internal tool calls before producing final text.
 - `fetch_url` sends browser-like navigation headers for outbound URL requests to reduce false 403s from sites that reject generic server clients.
 - `hermes-agent`: backend uses the configured Hermes Agent OpenAI-compatible Chat Completions API. Sybil does not add its own tool definitions for this provider; Hermes Agent handles its own tools server-side. Custom Hermes stream events are normalized away unless they produce text deltas in this SSE contract.
 - `openai`: image attachments are sent as Responses `input_image` items; text attachments are sent as `input_text` items.
+- `gemini`: image attachments are sent as native Gemini `inlineData` parts; text attachments are inlined as text parts.
 - `xai` and `hermes-agent`: image attachments are sent as Chat Completions content parts; text attachments are inlined as text parts.
 - `openai`: Responses calls that can enter the server-managed tool loop use `store: true` so reasoning and function-call items can be passed between tool rounds.
 - `anthropic`: streamed via event stream; emits `delta` from `content_block_delta` with `text_delta`, and emits normalized `tool_call` SSE events when Anthropic `tool_use` blocks are executed. Image attachments are sent as base64 `image` blocks and text attachments are appended as `text` blocks.
-- `web_search` uses `CHAT_WEB_SEARCH_ENGINE` (`exa` default, or `searxng` with `SEARXNG_BASE_URL` set). SearXNG mode requires the instance to allow `format=json`. This only affects chat-mode tool calls, not search-mode endpoints.
+- `web_search` uses `CHAT_WEB_SEARCH_ENGINE`: `exa` (default), `brave` (requires `BRAVE_SEARCH_API_KEY`), or `searxng` (requires `SEARXNG_BASE_URL`; the instance must allow `format=json`). This only affects chat-mode tool calls, not search-mode endpoints.
+- Brave searches are queued and evenly paced according to the shortest window in Brave's `X-RateLimit-Policy` response header. The backend also honors `X-RateLimit-Remaining`/`X-RateLimit-Reset` and retries `429` responses up to three times with reset-aware exponential backoff; quota resets beyond the bounded retry window fail immediately.
 - `codex_exec` is available only when `CHAT_CODEX_TOOL_ENABLED=true`. It SSHes to `CHAT_CODEX_REMOTE_HOST`, creates/uses `CHAT_CODEX_REMOTE_WORKDIR`, and runs `codex exec --dangerously-bypass-approvals-and-sandbox --skip-git-repo-check <non-interactive wrapped prompt>` there with SSH stdin closed. Prefer `CHAT_CODEX_SSH_KEY_PATH` with a read-only mounted private key; `CHAT_CODEX_SSH_PRIVATE_KEY_B64` is also supported.
 - `shell_exec` is available only when `CHAT_SHELL_TOOL_ENABLED=true`. It uses the same devbox SSH configuration, starts in `CHAT_CODEX_REMOTE_WORKDIR`, and runs non-interactive shell commands there with SSH stdin closed, not inside the Sybil server container.
 - `CHAT_MAX_TOOL_ROUNDS` controls how many model/tool result cycles may occur before the backend returns a tool-call limit message; default is 100.
 
-Tool-enabled streaming notes (`openai`/`anthropic`/`xai`):
+Tool-enabled streaming notes (`openai`/`anthropic`/`xai`/`gemini`):
 - Stream still emits standard `meta`, `delta`, `done|error` events.
 - Stream may emit `tool_call` events while tool calls are executed.
 - `delta` events carry assistant text and are emitted incrementally for normal text rounds. The backend may buffer model-native text briefly while determining whether a provider round contains tool calls.

ios/.env.example

@@ -1,24 +1,5 @@
-FASTLANE_APP_IDENTIFIER=net.buzzert.sybil2
-FASTLANE_TEAM_ID=DQQH5H6GBD
-FASTLANE_SKIP_UPDATE_CHECK=1
-FASTLANE_HIDE_CHANGELOG=1
-SYBIL_APP_STORE_APPLE_ID=6759442828
-SYBIL_PROVIDER_PUBLIC_ID=c043d167-ad88-4036-84ea-76c223f1b1b2
-SYBIL_PROVISIONING_PROFILE_SPECIFIER=Sybil AppStore CI
-SYBIL_PROVISIONING_PROFILE_UUID=
-SYBIL_CODE_SIGN_IDENTITY=Apple Distribution: James Magahern (DQQH5H6GBD)
-SYBIL_XCODE_CODE_SIGN_IDENTITY=6B74B268C4761720FB2051D01D8BB3E47B55D9F5
-SYBIL_EXPORT_SIGNING_CERTIFICATE=Apple Distribution
-SYBIL_SIGNING_CERTIFICATE_ID=
-SYBIL_SIGNING_KEYCHAIN=
-
-# App Store Connect API key settings for TestFlight upload and signing setup.
-APP_STORE_CONNECT_API_KEY_ID=
-APP_STORE_CONNECT_API_ISSUER_ID=
-APP_STORE_CONNECT_API_KEY_PATH=
-APP_STORE_CONNECT_API_KEY_CONTENT=
-APP_STORE_CONNECT_API_KEY_CONTENT_BASE64=false
-
-# Optional deployment overrides.
-SYBIL_BUILD_NUMBER=
-SYBIL_VERSION_TAG=
+ASC_KEY_ID=
+ASC_ISSUER_ID=
+ASC_KEY=
+MATCH_PASSWORD=
+MATCH_GIT_BASIC_AUTHORIZATION=

ios/AGENTS.md

@@ -57,4 +57,5 @@ Instructions for work under `/Users/buzzert/src/sybil-2/ios`.
   - OpenAI: `gpt-4.1-mini`
   - Anthropic: `claude-3-5-sonnet-latest`
   - xAI: `grok-3-mini`
+  - Gemini: `gemini-3.5-flash`
   - Hermes Agent: `hermes-agent`

ios/Gemfile

@@ -1,3 +1,3 @@
 source "https://rubygems.org"
 
-gem "fastlane"
+gem "fastlane", "2.237.0"

ios/Gemfile.lock

@@ -1,46 +1,49 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    CFPropertyList (3.0.9)
+    CFPropertyList (3.0.8)
     abbrev (0.1.2)
     addressable (2.9.0)
       public_suffix (>= 2.0.2, < 8.0)
     artifactory (3.0.17)
     atomos (0.1.3)
-    aws-eventstream (1.3.2)
-    aws-partitions (1.1109.0)
-    aws-sdk-core (3.224.1)
+    aws-eventstream (1.4.0)
+    aws-partitions (1.1274.0)
+    aws-sdk-core (3.254.0)
       aws-eventstream (~> 1, >= 1.3.0)
       aws-partitions (~> 1, >= 1.992.0)
       aws-sigv4 (~> 1.9)
       base64
+      bigdecimal
       jmespath (~> 1, >= 1.6.1)
       logger
-    aws-sdk-kms (1.101.0)
-      aws-sdk-core (~> 3, >= 3.216.0)
+    aws-sdk-kms (1.130.0)
+      aws-sdk-core (~> 3, >= 3.254.0)
       aws-sigv4 (~> 1.5)
-    aws-sdk-s3 (1.188.0)
-      aws-sdk-core (~> 3, >= 3.224.1)
+    aws-sdk-s3 (1.228.1)
+      aws-sdk-core (~> 3, >= 3.254.0)
       aws-sdk-kms (~> 1)
       aws-sigv4 (~> 1.5)
-    aws-sigv4 (1.11.0)
+    aws-sigv4 (1.12.1)
       aws-eventstream (~> 1, >= 1.0.2)
     babosa (1.0.4)
-    base64 (0.2.0)
+    base64 (0.3.0)
+    benchmark (0.5.0)
+    bigdecimal (4.1.2)
     claide (1.1.0)
     colored (1.2)
     colored2 (3.1.2)
     commander (4.6.0)
       highline (~> 2.0.0)
-    csv (3.3.5)
+    csv (3.3.6)
     declarative (0.0.20)
     digest-crc (0.7.0)
       rake (>= 12.0.0, < 14.0.0)
-    domain_name (0.5.20190701)
-      unf (>= 0.0.5, < 1.0.0)
+    domain_name (0.6.20240107)
     dotenv (2.8.1)
     emoji_regex (3.2.3)
-    excon (0.109.0)
+    excon (1.6.0)
+      logger
     faraday (1.10.6)
       faraday-em_http (~> 1.0)
       faraday-em_synchrony (~> 1.0)
@@ -70,42 +73,45 @@ GEM
     faraday_middleware (1.2.1)
       faraday (~> 1.0)
     fastimage (2.4.1)
-    fastlane (2.230.0)
-      CFPropertyList (>= 2.3, < 4.0.0)
-      abbrev (~> 0.1.2)
-      addressable (>= 2.8, < 3.0.0)
+    fastlane (2.237.0)
+      CFPropertyList (>= 2.3, < 5.0.0)
+      abbrev (~> 0.1)
+      addressable (>= 2.9.0, < 3.0.0)
       artifactory (~> 3.0)
-      aws-sdk-s3 (~> 1.0)
+      aws-sdk-s3 (~> 1.197)
       babosa (>= 1.0.3, < 2.0.0)
-      base64 (~> 0.2.0)
-      bundler (>= 1.12.0, < 3.0.0)
+      base64 (~> 0.2)
+      benchmark (>= 0.1.0)
+      bundler (>= 2.4.0, < 5.0.0)
       colored (~> 1.2)
       commander (~> 4.6)
       csv (~> 3.3)
       dotenv (>= 2.1.1, < 3.0.0)
       emoji_regex (>= 0.1, < 4.0)
-      excon (>= 0.71.0, < 1.0.0)
+      excon (>= 0.71.0, < 2.0.0)
       faraday (~> 1.0)
       faraday-cookie_jar (~> 0.0.6)
       faraday_middleware (~> 1.0)
       fastimage (>= 2.1.0, < 3.0.0)
-      fastlane-sirp (>= 1.0.0)
+      fastlane-sirp (>= 1.1.0)
       gh_inspector (>= 1.1.2, < 2.0.0)
       google-apis-androidpublisher_v3 (~> 0.3)
       google-apis-playcustomapp_v1 (~> 0.1)
-      google-cloud-env (>= 1.6.0, < 2.0.0)
+      google-cloud-env (>= 1.6.0, < 2.3.0)
       google-cloud-storage (~> 1.31)
       highline (~> 2.0)
       http-cookie (~> 1.0.5)
       json (< 3.0.0)
-      jwt (>= 2.1.0, < 3)
+      jwt (>= 2.10.3, < 4)
       logger (>= 1.6, < 2.0)
       mini_magick (>= 4.9.4, < 5.0.0)
+      multi_json (~> 1.12)
       multipart-post (>= 2.0.0, < 3.0.0)
-      mutex_m (~> 0.3.0)
+      mutex_m (~> 0.3)
       naturally (~> 2.2)
-      nkf (~> 0.2.0)
+      nkf (~> 0.2)
       optparse (>= 0.1.1, < 1.0.0)
+      ostruct (>= 0.1.0)
       plist (>= 3.1.0, < 4.0.0)
       rubyzip (>= 2.0.0, < 3.0.0)
       security (= 0.1.5)
@@ -120,41 +126,46 @@ GEM
       xcpretty-travis-formatter (>= 0.0.3, < 2.0.0)
     fastlane-sirp (1.1.0)
     gh_inspector (1.1.3)
-    google-apis-androidpublisher_v3 (0.54.0)
-      google-apis-core (>= 0.11.0, < 2.a)
-    google-apis-core (0.11.3)
+    google-apis-androidpublisher_v3 (0.106.0)
+      google-apis-core (>= 0.15.0, < 2.a)
+    google-apis-core (0.18.0)
       addressable (~> 2.5, >= 2.5.1)
-      googleauth (>= 0.16.2, < 2.a)
-      httpclient (>= 2.8.1, < 3.a)
+      googleauth (~> 1.9)
+      httpclient (>= 2.8.3, < 3.a)
       mini_mime (~> 1.0)
+      mutex_m
       representable (~> 3.0)
       retriable (>= 2.0, < 4.a)
-      rexml
-    google-apis-iamcredentials_v1 (0.17.0)
-      google-apis-core (>= 0.11.0, < 2.a)
-    google-apis-playcustomapp_v1 (0.13.0)
-      google-apis-core (>= 0.11.0, < 2.a)
-    google-apis-storage_v1 (0.29.0)
-      google-apis-core (>= 0.11.0, < 2.a)
-    google-cloud-core (1.6.1)
+    google-apis-iamcredentials_v1 (0.28.0)
+      google-apis-core (>= 0.15.0, < 2.a)
+    google-apis-playcustomapp_v1 (0.18.0)
+      google-apis-core (>= 0.15.0, < 2.a)
+    google-apis-storage_v1 (0.65.0)
+      google-apis-core (>= 0.15.0, < 2.a)
+    google-cloud-core (1.9.0)
       google-cloud-env (>= 1.0, < 3.a)
       google-cloud-errors (~> 1.0)
-    google-cloud-env (1.6.0)
-      faraday (>= 0.17.3, < 3.0)
-    google-cloud-errors (1.3.1)
-    google-cloud-storage (1.45.0)
+    google-cloud-env (2.2.2)
+      base64 (~> 0.2)
+      faraday (>= 1.0, < 3.a)
+    google-cloud-errors (1.7.0)
+    google-cloud-storage (1.62.0)
       addressable (~> 2.8)
       digest-crc (~> 0.4)
-      google-apis-iamcredentials_v1 (~> 0.1)
-      google-apis-storage_v1 (~> 0.29.0)
+      google-apis-core (>= 0.18, < 2)
+      google-apis-iamcredentials_v1 (~> 0.18)
+      google-apis-storage_v1 (>= 0.42)
       google-cloud-core (~> 1.6)
-      googleauth (>= 0.16.2, < 2.a)
+      googleauth (~> 1.9)
       mini_mime (~> 1.0)
-    googleauth (1.8.1)
-      faraday (>= 0.17.3, < 3.a)
-      jwt (>= 1.4, < 3.0)
-      multi_json (~> 1.11)
+    google-logging-utils (0.2.0)
+    googleauth (1.17.2)
+      faraday (>= 1.0, < 3.a)
+      google-cloud-env (~> 2.2)
+      google-logging-utils (~> 0.1)
+      jwt (>= 1.4, < 4.0)
       os (>= 0.9, < 2.0)
+      pstore (~> 0.1)
       signet (>= 0.16, < 2.a)
     highline (2.0.3)
     http-cookie (1.0.8)
@@ -162,22 +173,24 @@ GEM
     httpclient (2.9.0)
       mutex_m
     jmespath (1.6.2)
-    json (2.7.6)
-    jwt (2.10.3)
+    json (2.21.1)
+    jwt (3.2.0)
       base64
     logger (1.7.0)
     mini_magick (4.13.2)
     mini_mime (1.1.5)
-    multi_json (1.15.0)
+    multi_json (1.21.1)
     multipart-post (2.4.1)
     mutex_m (0.3.0)
     nanaimo (0.4.0)
     naturally (2.3.0)
-    nkf (0.2.0)
+    nkf (0.3.0)
     optparse (0.8.1)
     os (1.1.4)
+    ostruct (0.6.3)
     plist (3.7.2)
-    public_suffix (5.1.1)
+    pstore (0.2.1)
+    public_suffix (7.0.5)
     rake (13.4.2)
     representable (3.2.0)
       declarative (< 0.1.0)
@@ -189,11 +202,10 @@ GEM
     ruby2_keywords (0.0.5)
     rubyzip (2.4.1)
     security (0.1.5)
-    signet (0.18.0)
+    signet (0.22.0)
       addressable (~> 2.8)
       faraday (>= 0.17.5, < 3.a)
-      jwt (>= 1.5, < 3.0)
-      multi_json (~> 1.10)
+      jwt (>= 1.5, < 4.0)
     simctl (1.6.10)
       CFPropertyList
       naturally
@@ -206,15 +218,16 @@ GEM
     tty-spinner (0.9.3)
       tty-cursor (~> 0.7)
     uber (0.1.0)
-    unf (0.2.0)
     unicode-display_width (2.6.0)
     word_wrap (1.0.0)
-    xcodeproj (1.27.0)
+    xcodeproj (1.28.1)
       CFPropertyList (>= 2.3.3, < 4.0)
       atomos (~> 0.1.3)
+      base64
       claide (>= 1.0.2, < 2.0)
       colored2 (~> 3.1)
       nanaimo (~> 0.4.0)
+      nkf
       rexml (>= 3.3.6, < 4.0)
     xcpretty (0.4.1)
       rouge (~> 3.28.0)
@@ -225,7 +238,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  fastlane
+  fastlane (= 2.237.0)
 
 BUNDLED WITH
    2.5.23

ios/Packages/Sybil/Sources/Sybil/SybilChatTranscriptView.swift

@@ -67,7 +67,6 @@ struct SybilChatTranscriptView: View {
             .scrollDismissesKeyboard(.interactively)
             .onAppear {
                 syncKnownToolCallMessageIDs()
-                scrollToBottom(with: proxy, animated: false)
             }
             .onChange(of: toolCallMessageIDSignature) { _, _ in
                 syncKnownToolCallMessageIDs()

ios/Packages/Sybil/Sources/Sybil/SybilModels.swift

@@ -4,6 +4,7 @@ public enum Provider: String, Codable, CaseIterable, Hashable, Sendable {
     case openai
     case anthropic
     case xai
+    case gemini
     case hermesAgent = "hermes-agent"
 
     public var displayName: String {
@@ -11,6 +12,7 @@ public enum Provider: String, Codable, CaseIterable, Hashable, Sendable {
         case .openai: return "OpenAI"
         case .anthropic: return "Anthropic"
         case .xai: return "xAI"
+        case .gemini: return "Gemini"
         case .hermesAgent: return "Hermes Agent"
         }
     }
@@ -152,6 +154,8 @@ public struct ChatAttachment: Codable, Hashable, Identifiable, Sendable {
 public struct ChatSummary: Codable, Identifiable, Hashable, Sendable {
     public var id: String
     public var title: String?
+    public var parentChatId: String? = nil
+    public var titleGenerationPending = false
     public var createdAt: Date
     public var updatedAt: Date
     public var starred = false
@@ -162,6 +166,39 @@ public struct ChatSummary: Codable, Identifiable, Hashable, Sendable {
     public var lastUsedModel: String?
 }
 
+extension ChatSummary {
+    private enum CodingKeys: String, CodingKey {
+        case id
+        case title
+        case parentChatId
+        case titleGenerationPending
+        case createdAt
+        case updatedAt
+        case starred
+        case starredAt
+        case initiatedProvider
+        case initiatedModel
+        case lastUsedProvider
+        case lastUsedModel
+    }
+
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        id = try container.decode(String.self, forKey: .id)
+        title = try container.decodeIfPresent(String.self, forKey: .title)
+        parentChatId = try container.decodeIfPresent(String.self, forKey: .parentChatId)
+        titleGenerationPending = try container.decodeIfPresent(Bool.self, forKey: .titleGenerationPending) ?? false
+        createdAt = try container.decode(Date.self, forKey: .createdAt)
+        updatedAt = try container.decode(Date.self, forKey: .updatedAt)
+        starred = try container.decodeIfPresent(Bool.self, forKey: .starred) ?? false
+        starredAt = try container.decodeIfPresent(Date.self, forKey: .starredAt)
+        initiatedProvider = try container.decodeIfPresent(Provider.self, forKey: .initiatedProvider)
+        initiatedModel = try container.decodeIfPresent(String.self, forKey: .initiatedModel)
+        lastUsedProvider = try container.decodeIfPresent(Provider.self, forKey: .lastUsedProvider)
+        lastUsedModel = try container.decodeIfPresent(String.self, forKey: .lastUsedModel)
+    }
+}
+
 public struct SearchSummary: Codable, Identifiable, Hashable, Sendable {
     public var id: String
     public var title: String?
@@ -182,6 +219,8 @@ public struct WorkspaceItem: Codable, Identifiable, Hashable, Sendable {
     public var id: String
     public var title: String?
     public var query: String?
+    public var parentChatId: String? = nil
+    public var titleGenerationPending = false
     public var createdAt: Date
     public var updatedAt: Date
     public var starred = false
@@ -196,6 +235,8 @@ public struct WorkspaceItem: Codable, Identifiable, Hashable, Sendable {
         self.id = chat.id
         self.title = chat.title
         self.query = nil
+        self.parentChatId = chat.parentChatId
+        self.titleGenerationPending = chat.titleGenerationPending
         self.createdAt = chat.createdAt
         self.updatedAt = chat.updatedAt
         self.starred = chat.starred
@@ -211,6 +252,8 @@ public struct WorkspaceItem: Codable, Identifiable, Hashable, Sendable {
         self.id = search.id
         self.title = search.title
         self.query = search.query
+        self.parentChatId = nil
+        self.titleGenerationPending = false
         self.createdAt = search.createdAt
         self.updatedAt = search.updatedAt
         self.starred = search.starred
@@ -226,6 +269,8 @@ public struct WorkspaceItem: Codable, Identifiable, Hashable, Sendable {
         return ChatSummary(
             id: id,
             title: title,
+            parentChatId: parentChatId,
+            titleGenerationPending: titleGenerationPending,
             createdAt: createdAt,
             updatedAt: updatedAt,
             starred: starred,
@@ -251,6 +296,43 @@ public struct WorkspaceItem: Codable, Identifiable, Hashable, Sendable {
     }
 }
 
+extension WorkspaceItem {
+    private enum CodingKeys: String, CodingKey {
+        case type
+        case id
+        case title
+        case query
+        case parentChatId
+        case titleGenerationPending
+        case createdAt
+        case updatedAt
+        case starred
+        case starredAt
+        case initiatedProvider
+        case initiatedModel
+        case lastUsedProvider
+        case lastUsedModel
+    }
+
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        type = try container.decode(WorkspaceItemType.self, forKey: .type)
+        id = try container.decode(String.self, forKey: .id)
+        title = try container.decodeIfPresent(String.self, forKey: .title)
+        query = try container.decodeIfPresent(String.self, forKey: .query)
+        parentChatId = try container.decodeIfPresent(String.self, forKey: .parentChatId)
+        titleGenerationPending = try container.decodeIfPresent(Bool.self, forKey: .titleGenerationPending) ?? false
+        createdAt = try container.decode(Date.self, forKey: .createdAt)
+        updatedAt = try container.decode(Date.self, forKey: .updatedAt)
+        starred = try container.decodeIfPresent(Bool.self, forKey: .starred) ?? false
+        starredAt = try container.decodeIfPresent(Date.self, forKey: .starredAt)
+        initiatedProvider = try container.decodeIfPresent(Provider.self, forKey: .initiatedProvider)
+        initiatedModel = try container.decodeIfPresent(String.self, forKey: .initiatedModel)
+        lastUsedProvider = try container.decodeIfPresent(Provider.self, forKey: .lastUsedProvider)
+        lastUsedModel = try container.decodeIfPresent(String.self, forKey: .lastUsedModel)
+    }
+}
+
 public struct Message: Codable, Identifiable, Hashable, Sendable {
     public var id: String
     public var createdAt: Date
@@ -389,6 +471,8 @@ public enum JSONValue: Codable, Hashable, Sendable {
 public struct ChatDetail: Codable, Identifiable, Hashable, Sendable {
     public var id: String
     public var title: String?
+    public var parentChatId: String? = nil
+    public var titleGenerationPending = false
     public var createdAt: Date
     public var updatedAt: Date
     public var starred = false
@@ -400,6 +484,41 @@ public struct ChatDetail: Codable, Identifiable, Hashable, Sendable {
     public var messages: [Message]
 }
 
+extension ChatDetail {
+    private enum CodingKeys: String, CodingKey {
+        case id
+        case title
+        case parentChatId
+        case titleGenerationPending
+        case createdAt
+        case updatedAt
+        case starred
+        case starredAt
+        case initiatedProvider
+        case initiatedModel
+        case lastUsedProvider
+        case lastUsedModel
+        case messages
+    }
+
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        id = try container.decode(String.self, forKey: .id)
+        title = try container.decodeIfPresent(String.self, forKey: .title)
+        parentChatId = try container.decodeIfPresent(String.self, forKey: .parentChatId)
+        titleGenerationPending = try container.decodeIfPresent(Bool.self, forKey: .titleGenerationPending) ?? false
+        createdAt = try container.decode(Date.self, forKey: .createdAt)
+        updatedAt = try container.decode(Date.self, forKey: .updatedAt)
+        starred = try container.decodeIfPresent(Bool.self, forKey: .starred) ?? false
+        starredAt = try container.decodeIfPresent(Date.self, forKey: .starredAt)
+        initiatedProvider = try container.decodeIfPresent(Provider.self, forKey: .initiatedProvider)
+        initiatedModel = try container.decodeIfPresent(String.self, forKey: .initiatedModel)
+        lastUsedProvider = try container.decodeIfPresent(Provider.self, forKey: .lastUsedProvider)
+        lastUsedModel = try container.decodeIfPresent(String.self, forKey: .lastUsedModel)
+        messages = try container.decode([Message].self, forKey: .messages)
+    }
+}
+
 public struct SearchResultItem: Codable, Identifiable, Hashable, Sendable {
     public var id: String
     public var createdAt: Date

ios/Packages/Sybil/Sources/Sybil/SybilSettingsStore.swift

@@ -11,11 +11,13 @@ final class SybilSettingsStore {
         static let preferredOpenAIModel = "sybil.ios.preferredOpenAIModel"
         static let preferredAnthropicModel = "sybil.ios.preferredAnthropicModel"
         static let preferredXAIModel = "sybil.ios.preferredXAIModel"
+        static let preferredGeminiModel = "sybil.ios.preferredGeminiModel"
         static let preferredHermesAgentModel = "sybil.ios.preferredHermesAgentModel"
         static let quickQuestionPreferredProvider = "sybil.ios.quickQuestionPreferredProvider"
         static let quickQuestionPreferredOpenAIModel = "sybil.ios.quickQuestionPreferredOpenAIModel"
         static let quickQuestionPreferredAnthropicModel = "sybil.ios.quickQuestionPreferredAnthropicModel"
         static let quickQuestionPreferredXAIModel = "sybil.ios.quickQuestionPreferredXAIModel"
+        static let quickQuestionPreferredGeminiModel = "sybil.ios.quickQuestionPreferredGeminiModel"
         static let quickQuestionPreferredHermesAgentModel = "sybil.ios.quickQuestionPreferredHermesAgentModel"
     }
 
@@ -44,6 +46,7 @@ final class SybilSettingsStore {
             .openai: defaults.string(forKey: Keys.preferredOpenAIModel) ?? "gpt-4.1-mini",
             .anthropic: defaults.string(forKey: Keys.preferredAnthropicModel) ?? "claude-3-5-sonnet-latest",
             .xai: defaults.string(forKey: Keys.preferredXAIModel) ?? "grok-3-mini",
+            .gemini: defaults.string(forKey: Keys.preferredGeminiModel) ?? "gemini-3.5-flash",
             .hermesAgent: defaults.string(forKey: Keys.preferredHermesAgentModel) ?? "hermes-agent"
         ]
         self.preferredModelByProvider = preferredModels
@@ -54,6 +57,7 @@ final class SybilSettingsStore {
             .openai: defaults.string(forKey: Keys.quickQuestionPreferredOpenAIModel) ?? preferredModels[.openai] ?? "gpt-4.1-mini",
             .anthropic: defaults.string(forKey: Keys.quickQuestionPreferredAnthropicModel) ?? preferredModels[.anthropic] ?? "claude-3-5-sonnet-latest",
             .xai: defaults.string(forKey: Keys.quickQuestionPreferredXAIModel) ?? preferredModels[.xai] ?? "grok-3-mini",
+            .gemini: defaults.string(forKey: Keys.quickQuestionPreferredGeminiModel) ?? preferredModels[.gemini] ?? "gemini-3.5-flash",
             .hermesAgent: defaults.string(forKey: Keys.quickQuestionPreferredHermesAgentModel) ?? preferredModels[.hermesAgent] ?? "hermes-agent"
         ]
     }
@@ -72,12 +76,14 @@ final class SybilSettingsStore {
         defaults.set(preferredModelByProvider[.openai], forKey: Keys.preferredOpenAIModel)
         defaults.set(preferredModelByProvider[.anthropic], forKey: Keys.preferredAnthropicModel)
         defaults.set(preferredModelByProvider[.xai], forKey: Keys.preferredXAIModel)
+        defaults.set(preferredModelByProvider[.gemini], forKey: Keys.preferredGeminiModel)
         defaults.set(preferredModelByProvider[.hermesAgent], forKey: Keys.preferredHermesAgentModel)
 
         defaults.set(quickQuestionPreferredProvider.rawValue, forKey: Keys.quickQuestionPreferredProvider)
         defaults.set(quickQuestionPreferredModelByProvider[.openai], forKey: Keys.quickQuestionPreferredOpenAIModel)
         defaults.set(quickQuestionPreferredModelByProvider[.anthropic], forKey: Keys.quickQuestionPreferredAnthropicModel)
         defaults.set(quickQuestionPreferredModelByProvider[.xai], forKey: Keys.quickQuestionPreferredXAIModel)
+        defaults.set(quickQuestionPreferredModelByProvider[.gemini], forKey: Keys.quickQuestionPreferredGeminiModel)
         defaults.set(quickQuestionPreferredModelByProvider[.hermesAgent], forKey: Keys.quickQuestionPreferredHermesAgentModel)
     }
 

ios/Packages/Sybil/Sources/Sybil/SybilViewModel.swift

@@ -160,6 +160,7 @@ final class SybilViewModel {
         .openai: ["gpt-4.1-mini"],
         .anthropic: ["claude-3-5-sonnet-latest"],
         .xai: ["grok-3-mini"],
+        .gemini: ["gemini-3.5-flash", "gemini-flash-latest"],
         .hermesAgent: ["hermes-agent"]
     ]
 
@@ -405,14 +406,17 @@ final class SybilViewModel {
                 } else {
                     initiatedLabel = nil
                 }
+                let starOwner = item.parentChatId.flatMap { parentChatID in
+                    workspaceItems.first(where: { $0.type == .chat && $0.id == parentChatID })
+                } ?? item
 
                 return SidebarItem(
                     selection: .chat(item.id),
                     kind: .chat,
                     title: chatTitle(title: item.title, messages: nil),
                     updatedAt: item.updatedAt,
-                    starred: item.starred,
-                    starredAt: item.starredAt,
+                    starred: starOwner.starred,
+                    starredAt: starOwner.starredAt,
                     initiatedLabel: initiatedLabel,
                     isRunning: isChatRowRunning(item.id)
                 )
@@ -686,6 +690,8 @@ final class SybilViewModel {
             selectedChat = ChatDetail(
                 id: chat.id,
                 title: chat.title,
+                parentChatId: chat.parentChatId,
+                titleGenerationPending: chat.titleGenerationPending,
                 createdAt: chat.createdAt,
                 updatedAt: chat.updatedAt,
                 starred: chat.starred,
@@ -895,7 +901,8 @@ final class SybilViewModel {
                 let client = try client()
                 switch selection {
                 case let .chat(chatID):
-                    let updated = try await client.updateChatStar(chatID: chatID, starred: starred)
+                    let rootChatID = chatFamilyRootID(for: chatID)
+                    let updated = try await client.updateChatStar(chatID: rootChatID, starred: starred)
                     applyChatSummary(updated, moveToFront: false)
                 case let .search(searchID):
                     let updated = try await client.updateSearchStar(searchID: searchID, starred: starred)
@@ -1453,6 +1460,8 @@ final class SybilViewModel {
 
         if selectedChat?.id == chat.id {
             selectedChat?.title = chat.title
+            selectedChat?.parentChatId = chat.parentChatId
+            selectedChat?.titleGenerationPending = chat.titleGenerationPending
             selectedChat?.updatedAt = chat.updatedAt
             selectedChat?.starred = chat.starred
             selectedChat?.starredAt = chat.starredAt
@@ -1504,6 +1513,19 @@ final class SybilViewModel {
         workspaceItems.insert(item, at: 0)
     }
 
+    private func chatFamilyRootID(for chatID: String) -> String {
+        if let selectedChat, selectedChat.id == chatID, let parentChatID = selectedChat.parentChatId {
+            return parentChatID
+        }
+        if let parentChatID = chats.first(where: { $0.id == chatID })?.parentChatId {
+            return parentChatID
+        }
+        if let parentChatID = workspaceItems.first(where: { $0.type == .chat && $0.id == chatID })?.parentChatId {
+            return parentChatID
+        }
+        return chatID
+    }
+
     private func attachToVisibleActiveRunIfNeeded() {
         guard draftKind == nil else {
             return
@@ -1751,13 +1773,16 @@ final class SybilViewModel {
                 switch target {
                 case let .chat(chatID):
                     SybilLog.debug(SybilLog.app, "Refreshing chat \(chatID)")
+                    let isSelectingDifferentChat = selectedChat?.id != chatID
                     let chat = try await client.getChat(chatID: chatID)
                     guard selectedItem == target, draftKind == nil else {
                         return
                     }
                     selectedChat = chat
                     selectedSearch = nil
-                    requestChatBottomPin()
+                    if isSelectingDifferentChat {
+                        requestChatBottomPin()
+                    }
 
                     if let provider = chat.lastUsedProvider,
                        let model = chat.lastUsedModel,
@@ -1850,6 +1875,8 @@ final class SybilViewModel {
                 selectedChat = ChatDetail(
                     id: created.id,
                     title: created.title,
+                    parentChatId: created.parentChatId,
+                    titleGenerationPending: created.titleGenerationPending,
                     createdAt: created.createdAt,
                     updatedAt: created.updatedAt,
                     starred: created.starred,
@@ -1908,7 +1935,7 @@ final class SybilViewModel {
         let streamLifecycleGeneration = appLifecycleGeneration
         let streamStartedWhileInactive = !isAppActive
 
-        if isUntitledChat(chatID: chatID, detail: currentSelectedChat) {
+        if shouldRequestChatTitle(baseChat) {
             Task { [weak self] in
                 guard let self else { return }
                 do {
@@ -2619,20 +2646,10 @@ final class SybilViewModel {
         )
     }
 
-    private func isUntitledChat(chatID: String, detail: ChatDetail?) -> Bool {
-        if let detail, detail.id == chatID {
-            if let title = detail.title?.trimmingCharacters(in: .whitespacesAndNewlines), !title.isEmpty {
-                return false
-            }
+    private func shouldRequestChatTitle(_ chat: ChatDetail) -> Bool {
+        if chat.titleGenerationPending {
             return true
         }
-
-        if let summary = chats.first(where: { $0.id == chatID }) {
-            if let title = summary.title?.trimmingCharacters(in: .whitespacesAndNewlines), !title.isEmpty {
-                return false
-            }
-        }
-
-        return true
+        return chat.title?.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ?? true
     }
 }

ios/Packages/Sybil/Tests/SybilTests/SybilTests.swift

@@ -10,7 +10,10 @@ private struct MockClientCallSnapshot: Sendable {
     var createChat = 0
     var getChat = 0
     var updateChatTitle = 0
+    var suggestChatTitle = 0
     var updateChatStar = 0
+    var lastUpdateChatStarID: String?
+    var lastUpdateChatStarred: Bool?
     var updateSearchStar = 0
     var getSearch = 0
     var getActiveRuns = 0
@@ -36,6 +39,7 @@ private actor MockSybilClient: SybilAPIClienting {
     private let searchDetails: [String: SearchDetail]
     private let createChatResponse: ChatSummary?
     private let updateChatTitleResponses: [String: ChatSummary]
+    private let suggestChatTitleResponses: [String: ChatSummary]
     private let updateChatStarResponses: [String: ChatSummary]
     private let updateSearchStarResponses: [String: SearchSummary]
     private let activeRunsResponse: ActiveRunsResponse
@@ -64,6 +68,7 @@ private actor MockSybilClient: SybilAPIClienting {
         searchDetails: [String: SearchDetail] = [:],
         createChatResponse: ChatSummary? = nil,
         updateChatTitleResponses: [String: ChatSummary] = [:],
+        suggestChatTitleResponses: [String: ChatSummary] = [:],
         updateChatStarResponses: [String: ChatSummary] = [:],
         updateSearchStarResponses: [String: SearchSummary] = [:],
         activeRunsResponse: ActiveRunsResponse = ActiveRunsResponse(),
@@ -76,6 +81,7 @@ private actor MockSybilClient: SybilAPIClienting {
         self.searchDetails = searchDetails
         self.createChatResponse = createChatResponse
         self.updateChatTitleResponses = updateChatTitleResponses
+        self.suggestChatTitleResponses = suggestChatTitleResponses
         self.updateChatStarResponses = updateChatStarResponses
         self.updateSearchStarResponses = updateSearchStarResponses
         self.activeRunsResponse = activeRunsResponse
@@ -204,6 +210,8 @@ private actor MockSybilClient: SybilAPIClienting {
 
     func updateChatStar(chatID: String, starred: Bool) async throws -> ChatSummary {
         snapshot.updateChatStar += 1
+        snapshot.lastUpdateChatStarID = chatID
+        snapshot.lastUpdateChatStarred = starred
         guard let summary = updateChatStarResponses[chatID] else {
             throw UnexpectedClientCall()
         }
@@ -215,7 +223,11 @@ private actor MockSybilClient: SybilAPIClienting {
     }
 
     func suggestChatTitle(chatID: String, content: String) async throws -> ChatSummary {
-        throw UnexpectedClientCall()
+        snapshot.suggestChatTitle += 1
+        guard let summary = suggestChatTitleResponses[chatID] else {
+            throw UnexpectedClientCall()
+        }
+        return summary
     }
 
     func listSearches() async throws -> [SearchSummary] {
@@ -420,6 +432,46 @@ private func makeToolCallMessage(id: String, date: Date, summary: String = "Ran
     )
 }
 
+@Test func chatForkMetadataDecodesBackwardCompatiblyAndSurvivesWorkspaceConversions() throws {
+    let decoder = JSONDecoder()
+    let legacySummary = try decoder.decode(
+        ChatSummary.self,
+        from: Data(#"{"id":"legacy-chat","title":"Legacy","createdAt":0,"updatedAt":1}"#.utf8)
+    )
+    let legacyWorkspaceItem = try decoder.decode(
+        WorkspaceItem.self,
+        from: Data(#"{"type":"chat","id":"legacy-chat","title":"Legacy","createdAt":0,"updatedAt":1}"#.utf8)
+    )
+    let legacyDetail = try decoder.decode(
+        ChatDetail.self,
+        from: Data(#"{"id":"legacy-chat","title":"Legacy","createdAt":0,"updatedAt":1,"messages":[]}"#.utf8)
+    )
+    let forkDetail = try decoder.decode(
+        ChatDetail.self,
+        from: Data(#"{"id":"fork-chat","title":"Fork of Legacy","parentChatId":"root-chat","titleGenerationPending":true,"createdAt":0,"updatedAt":1,"messages":[]}"#.utf8)
+    )
+
+    #expect(legacySummary.parentChatId == nil)
+    #expect(!legacySummary.titleGenerationPending)
+    #expect(legacyWorkspaceItem.parentChatId == nil)
+    #expect(!legacyWorkspaceItem.titleGenerationPending)
+    #expect(legacyDetail.parentChatId == nil)
+    #expect(!legacyDetail.titleGenerationPending)
+    #expect(forkDetail.parentChatId == "root-chat")
+    #expect(forkDetail.titleGenerationPending)
+
+    var fork = legacySummary
+    fork.parentChatId = "root-chat"
+    fork.titleGenerationPending = true
+
+    let workspaceItem = WorkspaceItem(chat: fork)
+    let restoredSummary = try #require(workspaceItem.chatSummary)
+    #expect(workspaceItem.parentChatId == "root-chat")
+    #expect(workspaceItem.titleGenerationPending)
+    #expect(restoredSummary.parentChatId == "root-chat")
+    #expect(restoredSummary.titleGenerationPending)
+}
+
 @Test func transcriptRenderItemsGroupAdjacentToolCalls() async throws {
     let date = Date(timeIntervalSince1970: 1_700_000_000)
     let user = Message(id: "user-1", createdAt: date, role: .user, content: "Search this", name: nil)
@@ -544,12 +596,14 @@ private func makeToolCallMessage(id: String, date: Date, summary: String = "Ran
 @MainActor
 @Test func foregroundChatRefreshReloadsSelectedTranscript() async throws {
     let date = Date(timeIntervalSince1970: 1_700_000_100)
+    let staleDetail = makeChatDetail(id: "chat-2", date: date, body: "stale transcript")
     let detail = makeChatDetail(id: "chat-2", date: date, body: "refreshed transcript")
     let client = MockSybilClient(chatDetails: ["chat-2": detail])
     let viewModel = SybilViewModel(settings: testSettings(named: #function)) { _ in client }
     viewModel.isAuthenticated = true
     viewModel.isCheckingSession = false
     viewModel.selectedItem = .chat("chat-2")
+    viewModel.selectedChat = staleDetail
 
     await viewModel.refreshVisibleContent(refreshCollections: false, refreshSelection: true)
 
@@ -559,24 +613,22 @@ private func makeToolCallMessage(id: String, date: Date, summary: String = "Ran
     #expect(snapshot.listSearches == 0)
     #expect(snapshot.getChat == 1)
     #expect(viewModel.selectedChat?.messages.first?.content == "refreshed transcript")
-    #expect(viewModel.chatBottomPinRequestID == 1)
+    #expect(viewModel.chatBottomPinRequestID == 0)
 }
 
 @MainActor
 @Test func renameChatUpdatesSidebarAndSelectedTranscriptTitle() async throws {
     let date = Date(timeIntervalSince1970: 1_700_000_150)
-    let original = makeChatSummary(id: "chat-rename", date: date)
-    let renamed = ChatSummary(
-        id: "chat-rename",
-        title: "Renamed chat",
-        createdAt: date,
-        updatedAt: date.addingTimeInterval(60),
-        initiatedProvider: .openai,
-        initiatedModel: "gpt-4.1-mini",
-        lastUsedProvider: .openai,
-        lastUsedModel: "gpt-4.1-mini"
-    )
-    let detail = makeChatDetail(id: "chat-rename", date: date, body: "existing transcript")
+    var original = makeChatSummary(id: "chat-rename", date: date)
+    original.parentChatId = "root-chat"
+    original.titleGenerationPending = true
+    var renamed = original
+    renamed.title = "Renamed chat"
+    renamed.titleGenerationPending = false
+    renamed.updatedAt = date.addingTimeInterval(60)
+    var detail = makeChatDetail(id: "chat-rename", date: date, body: "existing transcript")
+    detail.parentChatId = original.parentChatId
+    detail.titleGenerationPending = original.titleGenerationPending
     let client = MockSybilClient(
         chatsResponse: [original],
         updateChatTitleResponses: ["chat-rename": renamed]
@@ -594,7 +646,13 @@ private func makeToolCallMessage(id: String, date: Date, summary: String = "Ran
     let snapshot = await client.currentSnapshot()
     #expect(snapshot.updateChatTitle == 1)
     #expect(viewModel.sidebarItems.first?.title == "Renamed chat")
+    #expect(viewModel.chats.first?.parentChatId == "root-chat")
+    #expect(viewModel.chats.first?.titleGenerationPending == false)
+    #expect(viewModel.workspaceItems.first?.parentChatId == "root-chat")
+    #expect(viewModel.workspaceItems.first?.titleGenerationPending == false)
     #expect(viewModel.selectedChat?.title == "Renamed chat")
+    #expect(viewModel.selectedChat?.parentChatId == "root-chat")
+    #expect(viewModel.selectedChat?.titleGenerationPending == false)
     #expect(viewModel.errorMessage == nil)
 }
 
@@ -633,6 +691,54 @@ private func makeToolCallMessage(id: String, date: Date, summary: String = "Ran
     #expect(viewModel.sidebarItems.first(where: { $0.selection == .search("search-star") })?.starred == true)
 }
 
+@MainActor
+@Test func unstarringForkTargetsRootWithoutReplacingSelectedChild() async throws {
+    let date = Date(timeIntervalSince1970: 1_700_000_180)
+    var root = makeChatSummary(id: "chat-root", date: date)
+    root.starred = true
+    root.starredAt = date.addingTimeInterval(5)
+
+    var child = makeChatSummary(id: "chat-child", date: date.addingTimeInterval(1))
+    child.parentChatId = root.id
+    child.titleGenerationPending = true
+
+    var childDetail = makeChatDetail(id: child.id, date: date, body: "forked transcript")
+    childDetail.title = child.title
+    childDetail.parentChatId = root.id
+    childDetail.titleGenerationPending = true
+
+    var unstarredRoot = root
+    unstarredRoot.starred = false
+    unstarredRoot.starredAt = nil
+
+    let client = MockSybilClient(
+        chatsResponse: [root, child],
+        updateChatStarResponses: [root.id: unstarredRoot]
+    )
+    let viewModel = SybilViewModel(settings: testSettings(named: #function)) { _ in client }
+    viewModel.isAuthenticated = true
+    viewModel.isCheckingSession = false
+    viewModel.chats = [root, child]
+    viewModel.workspaceItems = [WorkspaceItem(chat: root), WorkspaceItem(chat: child)]
+    viewModel.selectedItem = .chat(child.id)
+    viewModel.selectedChat = childDetail
+
+    #expect(viewModel.sidebarItems.first(where: { $0.selection == .chat(child.id) })?.starred == true)
+
+    await viewModel.setItemStarred(.chat(child.id), starred: false)
+
+    let snapshot = await client.currentSnapshot()
+    #expect(snapshot.updateChatStar == 1)
+    #expect(snapshot.lastUpdateChatStarID == root.id)
+    #expect(snapshot.lastUpdateChatStarred == false)
+    #expect(viewModel.chats.first(where: { $0.id == root.id })?.starred == false)
+    #expect(viewModel.chats.first(where: { $0.id == child.id }) == child)
+    #expect(viewModel.sidebarItems.first(where: { $0.selection == .chat(child.id) })?.starred == false)
+    #expect(viewModel.selectedItem == .chat(child.id))
+    #expect(viewModel.selectedChat == childDetail)
+    #expect(viewModel.errorMessage == nil)
+}
+
 @MainActor
 @Test func foregroundSearchRefreshReloadsSelectedSearch() async throws {
     let date = Date(timeIntervalSince1970: 1_700_000_200)
@@ -675,6 +781,7 @@ private func makeToolCallMessage(id: String, date: Date, summary: String = "Ran
 
     #expect(viewModel.displayedMessages.first?.content == "fresh transcript")
     #expect(!viewModel.isLoadingSelection)
+    #expect(viewModel.chatBottomPinRequestID == 1)
 }
 
 @MainActor
@@ -778,6 +885,72 @@ private func makeToolCallMessage(id: String, date: Date, summary: String = "Ran
     #expect(viewModel.chatBottomPinRequestID == initialPinRequestID + 1)
 }
 
+@MainActor
+@Test func firstPromptInPendingForkRequestsAndAppliesGeneratedTitle() async throws {
+    let date = Date(timeIntervalSince1970: 1_700_000_247)
+    var fork = makeChatSummary(id: "chat-fork", date: date)
+    fork.title = "Fork of Original chat"
+    fork.parentChatId = "root-chat"
+    fork.titleGenerationPending = true
+
+    var forkDetail = makeChatDetail(id: fork.id, date: date, body: "forked transcript")
+    forkDetail.title = fork.title
+    forkDetail.parentChatId = fork.parentChatId
+    forkDetail.titleGenerationPending = true
+
+    var titledFork = fork
+    titledFork.title = "Investigating the follow-up"
+    titledFork.titleGenerationPending = false
+    titledFork.updatedAt = date.addingTimeInterval(1)
+
+    var titledForkDetail = forkDetail
+    titledForkDetail.title = titledFork.title
+    titledForkDetail.titleGenerationPending = false
+    titledForkDetail.updatedAt = titledFork.updatedAt
+
+    let client = MockSybilClient(
+        chatsResponse: [titledFork],
+        chatDetails: [fork.id: titledForkDetail],
+        suggestChatTitleResponses: [fork.id: titledFork]
+    )
+    await client.setCompletionStreamEvents(
+        [.done(CompletionStreamDone(text: "Follow-up answer"))],
+        delayNanoseconds: 100_000_000
+    )
+
+    let viewModel = SybilViewModel(settings: testSettings(named: #function)) { _ in client }
+    viewModel.isAuthenticated = true
+    viewModel.isCheckingSession = false
+    viewModel.chats = [fork]
+    viewModel.workspaceItems = [WorkspaceItem(chat: fork)]
+    viewModel.selectedItem = .chat(fork.id)
+    viewModel.selectedChat = forkDetail
+    viewModel.composer = "Investigate this follow-up"
+
+    let sendTask = Task {
+        await viewModel.sendComposer()
+    }
+
+    for _ in 0..<20 {
+        let snapshot = await client.currentSnapshot()
+        if snapshot.suggestChatTitle == 1,
+           viewModel.selectedChat?.title == titledFork.title,
+           viewModel.selectedChat?.titleGenerationPending == false {
+            break
+        }
+        try await Task.sleep(nanoseconds: 5_000_000)
+    }
+
+    let titleSnapshot = await client.currentSnapshot()
+    #expect(titleSnapshot.suggestChatTitle == 1)
+    #expect(viewModel.chats.first?.title == titledFork.title)
+    #expect(viewModel.workspaceItems.first?.title == titledFork.title)
+    #expect(viewModel.selectedChat?.title == titledFork.title)
+    #expect(viewModel.selectedChat?.titleGenerationPending == false)
+
+    await sendTask.value
+}
+
 @MainActor
 @Test func quickQuestionRunsNonPersistentCompletionStream() async throws {
     let client = MockSybilClient()

ios/fastlane/Appfile

@@ -0,0 +1,2 @@
+app_identifier("net.buzzert.sybil2")
+team_id("DQQH5H6GBD")

ios/fastlane/Fastfile

@@ -1,169 +1,47 @@
-require "shellwords"
-
 default_platform(:ios)
 
-APP_IDENTIFIER = "net.buzzert.sybil2"
-SCHEME = "Sybil"
-TEAM_ID = "DQQH5H6GBD"
-PROFILE_NAME = "Sybil AppStore CI"
-CI_KEYCHAIN_NAME = "sybil_ci_keychain"
-CI_KEYCHAIN_PASSWORD = "sybil-ci-keychain-password"
-CI_KEYCHAIN_PATH = File.expand_path("~/Library/Keychains/#{CI_KEYCHAIN_NAME}")
-CI_KEYCHAIN_DB_PATH = "#{CI_KEYCHAIN_PATH}-db"
-IOS_ROOT = File.expand_path("..", __dir__)
-PROJECT_FILE = File.join(IOS_ROOT, "Sybil.xcodeproj")
-PROJECT_SPEC = File.join(IOS_ROOT, "project.yml")
-APP_PROJECT_SPEC = File.join(IOS_ROOT, "Apps/Sybil/project.yml")
-
-def present?(value)
-  !value.to_s.strip.empty?
-end
-
-def ci?
-  present?(ENV["CI"])
-end
-
-def release_version
-  tag = ENV["SYBIL_VERSION_TAG"]
-  tag = ENV["GITHUB_REF_NAME"] if !present?(tag)
-  tag = ENV["GITHUB_REF"].to_s.sub(%r{\Arefs/tags/}, "") if !present?(tag)
-  tag = sh("git describe --tags --abbrev=0").strip if !present?(tag)
-  match = tag.to_s.match(%r{\Arelease/ios/v(\d+\.\d+\.\d+)\z})
-
-  unless match
-    UI.user_error!("Release tag must look like release/ios/v1.2.3; got #{tag.inspect}")
-  end
-
-  match[1]
-end
-
-# App Store Connect requires CFBundleVersion to be unique and strictly
-# increasing app-wide (not just per marketing version), so we derive it from
-# the monotonic CI run number rather than querying TestFlight (that query can
-# lag behind builds still processing and hand back a colliding value).
-def build_number
-  value = present?(ENV["SYBIL_BUILD_NUMBER"]) ? ENV["SYBIL_BUILD_NUMBER"] : ENV["GITHUB_RUN_NUMBER"]
-
-  unless value.to_s.match?(/\A\d+\z/)
-    UI.user_error!("Build number must come from SYBIL_BUILD_NUMBER/GITHUB_RUN_NUMBER; got #{value.inspect}")
-  end
-
-  value.to_i
-end
-
-def stamp_marketing_version(version)
-  contents = File.read(APP_PROJECT_SPEC)
-  updated = contents.sub(/^(\s*MARKETING_VERSION:\s*).*/, "\\1\"#{version}\"")
-
-  if updated == contents
-    UI.user_error!("Could not find MARKETING_VERSION in #{APP_PROJECT_SPEC}")
-  end
-
-  File.write(APP_PROJECT_SPEC, updated)
-end
-
-def ci_keychain_path
-  File.file?(CI_KEYCHAIN_DB_PATH) ? CI_KEYCHAIN_DB_PATH : CI_KEYCHAIN_PATH
-end
-
-def signing_xcargs
-  args = [
-    "DEVELOPMENT_TEAM=#{TEAM_ID.shellescape}",
-    "CODE_SIGN_STYLE=Manual",
-    "CODE_SIGN_IDENTITY=Apple\\ Distribution",
-    "PROVISIONING_PROFILE_SPECIFIER=#{PROFILE_NAME.shellescape}"
-  ]
-
-  if ci?
-    args << "CODE_SIGN_KEYCHAIN=#{ci_keychain_path.shellescape}"
-    args << "OTHER_CODE_SIGN_FLAGS=#{("--keychain #{ci_keychain_path}").shellescape}"
-  end
-
-  args.join(" ")
-end
-
 platform :ios do
-  private_lane :app_store_api_key do
-    app_store_connect_api_key(
-      key_id: ENV.fetch("APP_STORE_CONNECT_KEY_ID"),
-      issuer_id: ENV.fetch("APP_STORE_CONNECT_ISSUER_ID"),
-      key_content: ENV.fetch("APP_STORE_CONNECT_KEY_CONTENT"),
+  desc "Build a release tag and upload it to TestFlight"
+  lane :beta do
+    setup_ci
+
+    match(type: "appstore")
+
+    tag = ENV.fetch("GITHUB_REF_NAME")
+    version = tag[%r{\Arelease/ios/v(\d+\.\d+\.\d+)\z}, 1]
+    UI.user_error!("Expected a tag in the form release/ios/vX.Y.Z; got #{tag.inspect}") unless version
+
+    build_number = ENV.fetch("GITHUB_RUN_NUMBER")
+    UI.user_error!("GITHUB_RUN_NUMBER must be a positive integer") unless build_number.match?(/\A[1-9]\d*\z/)
+
+    ios_dir = File.expand_path("..", __dir__)
+    project_spec = File.join(ios_dir, "Apps/Sybil/project.yml")
+    contents = File.read(project_spec)
+    unless contents.match?(/^\s*MARKETING_VERSION:/) && contents.match?(/^\s*CURRENT_PROJECT_VERSION:/)
+      UI.user_error!("Could not find version settings in #{project_spec}")
+    end
+    contents.sub!(/^(\s*MARKETING_VERSION:\s*).*/, "\\1\"#{version}\"")
+    contents.sub!(/^(\s*CURRENT_PROJECT_VERSION:\s*).*/, "\\1#{build_number}")
+    File.write(project_spec, contents)
+
+    sh("xcodegen", "--spec", File.join(ios_dir, "project.yml"))
+
+    api_key = app_store_connect_api_key(
+      key_id: ENV.fetch("ASC_KEY_ID"),
+      issuer_id: ENV.fetch("ASC_ISSUER_ID"),
+      key_content: ENV.fetch("ASC_KEY"),
       is_key_content_base64: true
     )
-  end
-
-  # CI uses a dedicated throwaway keychain for match. build_app passes this
-  # keychain explicitly so codesign does not depend on the runner's ambient
-  # login/default keychain state.
-  private_lane :prepare_ci_keychain do
-    next unless ci?
-
-    delete_keychain(name: CI_KEYCHAIN_NAME) if File.file?(CI_KEYCHAIN_DB_PATH) || File.file?(CI_KEYCHAIN_PATH)
-    create_keychain(
-      name: CI_KEYCHAIN_NAME,
-      password: CI_KEYCHAIN_PASSWORD,
-      unlock: true,
-      timeout: 3600,
-      add_to_search_list: true
-    )
-
-    ENV["MATCH_KEYCHAIN_NAME"] = CI_KEYCHAIN_NAME
-    ENV["MATCH_KEYCHAIN_PASSWORD"] = CI_KEYCHAIN_PASSWORD
-  end
-
-  private_lane :sync_signing do |options|
-    match(
-      type: "appstore",
-      readonly: options.fetch(:readonly),
-      app_identifier: APP_IDENTIFIER,
-      team_id: TEAM_ID,
-      profile_name: PROFILE_NAME,
-      git_url: ENV.fetch("MATCH_GIT_URL"),
-      git_branch: "master",
-      git_full_name: "Sybil Release Bot",
-      git_user_email: "james.magahern@me.com",
-      api_key: options.fetch(:api_key)
-    )
-  end
-
-  desc "Create or update match signing assets"
-  lane :setup_signing do
-    sync_signing(api_key: app_store_api_key, readonly: false)
-  end
-
-  desc "Build and upload to TestFlight"
-  lane :beta do
-    prepare_ci_keychain
-
-    api_key = app_store_api_key
-
-    version = release_version
-    stamp_marketing_version(version)
-    sh("xcodegen", "--spec", PROJECT_SPEC)
-
-    increment_version_number(version_number: version, xcodeproj: PROJECT_FILE)
-    increment_build_number(build_number: build_number, xcodeproj: PROJECT_FILE)
-
-    sync_signing(api_key: api_key, readonly: true)
 
     build_app(
-      project: PROJECT_FILE,
-      scheme: SCHEME,
-      export_method: "app-store",
-      codesigning_identity: "Apple Distribution",
-      xcargs: signing_xcargs,
-      export_options: {
-        signingStyle: "manual",
-        teamID: TEAM_ID,
-        provisioningProfiles: {
-          APP_IDENTIFIER => PROFILE_NAME
-        }
-      }
+      project: File.join(ios_dir, "Sybil.xcodeproj"),
+      scheme: "Sybil"
     )
 
     upload_to_testflight(
       api_key: api_key,
-      skip_waiting_for_build_processing: true
+      skip_waiting_for_build_processing: true,
+      uses_non_exempt_encryption: false
     )
   end
 end

ios/fastlane/Matchfile

@@ -0,0 +1,7 @@
+git_url("https://code.buzzert.dev/buzzert/fastlane-match.git")
+storage_mode("git")
+type("appstore")
+
+app_identifier(["net.buzzert.sybil2"])
+team_id("DQQH5H6GBD")
+profile_name("Sybil AppStore CI")

server/README.md

@@ -1,7 +1,7 @@
 # Sybil Server
 
 Backend API for:
-- LLM multiplexer (OpenAI Responses / Anthropic / xAI Chat Completions-compatible Grok / Hermes Agent)
+- LLM multiplexer (OpenAI Responses / Anthropic / xAI Chat Completions-compatible Grok / Gemini / Hermes Agent)
 - Personal chat database (chats/messages + LLM call log)
 
 ## Stack
@@ -43,14 +43,16 @@ If `ADMIN_TOKEN` is not set, the server runs in open mode (dev).
 - `OPENAI_API_KEY`
 - `ANTHROPIC_API_KEY`
 - `XAI_API_KEY`
+- `GEMINI_API_KEY`
 - `HERMES_AGENT_API_BASE_URL` (`http://127.0.0.1:8642/v1` by default; include the `/v1` suffix)
 - `HERMES_AGENT_API_KEY` (enables the Hermes Agent provider; set to Hermes `API_SERVER_KEY`, or any non-empty value if that local server does not require auth)
 - `HERMES_AGENT_MODEL` (optional fallback/override model id; defaults client-side to `hermes-agent`)
 - `EXA_API_KEY`
-- `CHAT_WEB_SEARCH_ENGINE` (`exa` by default, or `searxng` for chat tool calls only)
+- `BRAVE_SEARCH_API_KEY` (required when `CHAT_WEB_SEARCH_ENGINE=brave`)
+- `CHAT_WEB_SEARCH_ENGINE` (`exa` by default; `brave` and `searxng` are also supported for chat tool calls only)
 - `SEARXNG_BASE_URL` (required when `CHAT_WEB_SEARCH_ENGINE=searxng`; instance must allow `format=json`)
 - `CHAT_MAX_TOOL_ROUNDS` (`100` by default; maximum model/tool result cycles per chat completion)
-- `CHAT_CODEX_TOOL_ENABLED` (`false` by default; enables the `codex_exec` chat tool for OpenAI/xAI)
+- `CHAT_CODEX_TOOL_ENABLED` (`false` by default; enables the `codex_exec` chat tool for managed-tool providers)
 - `CHAT_CODEX_REMOTE_HOST` (required when Codex tool is enabled; SSH host/IP or `user@host`)
 - `CHAT_CODEX_REMOTE_USER` (optional SSH user when host does not include one)
 - `CHAT_CODEX_REMOTE_PORT` (`22` by default)
@@ -58,7 +60,7 @@ If `ADMIN_TOKEN` is not set, the server runs in open mode (dev).
 - `CHAT_CODEX_SSH_KEY_PATH` (recommended: path to a read-only mounted private key)
 - `CHAT_CODEX_SSH_PRIVATE_KEY_B64` (optional fallback private key delivery)
 - `CHAT_CODEX_EXEC_TIMEOUT_MS` (`600000` by default)
-- `CHAT_SHELL_TOOL_ENABLED` (`false` by default; enables the `shell_exec` chat tool for OpenAI/xAI on the same devbox)
+- `CHAT_SHELL_TOOL_ENABLED` (`false` by default; enables the `shell_exec` chat tool for managed-tool providers on the same devbox)
 - `CHAT_SHELL_EXEC_TIMEOUT_MS` (`120000` by default)
 
 ## API

server/prisma/migrations/20260816000000_add_chat_forks/migration.sql

@@ -0,0 +1,5 @@
+-- Add durable root grouping and one-time fork title generation state.
+ALTER TABLE "Chat" ADD COLUMN "parentChatId" TEXT REFERENCES "Chat"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+ALTER TABLE "Chat" ADD COLUMN "titleGenerationPending" BOOLEAN NOT NULL DEFAULT false;
+
+CREATE INDEX "Chat_parentChatId_idx" ON "Chat"("parentChatId");

server/prisma/schema.prisma

@@ -13,6 +13,7 @@ enum Provider {
   openai
   anthropic
   xai
+  gemini
   hermes_agent @map("hermes-agent")
 }
 
@@ -50,7 +51,8 @@ model Chat {
   createdAt DateTime @default(now())
   updatedAt DateTime @updatedAt
 
-  title String?
+  title                  String?
+  titleGenerationPending Boolean @default(false)
 
   initiatedProvider Provider?
   initiatedModel    String?
@@ -63,11 +65,17 @@ model Chat {
   user   User?   @relation(fields: [userId], references: [id])
   userId String?
 
+  // Forks always point directly to the single root chat, never to another fork.
+  parentChat   Chat?  @relation("ChatForks", fields: [parentChatId], references: [id], onDelete: Cascade)
+  parentChatId String?
+  childChats   Chat[] @relation("ChatForks")
+
   messages Message[]
   calls    LlmCall[]
   projectItems ProjectItem[]
 
   @@index([userId])
+  @@index([parentChatId])
 }
 
 model Message {

server/src/env.ts

@@ -24,7 +24,7 @@ const ChatWebSearchEngineSchema = z.preprocess(
     const trimmed = value.trim();
     return trimmed ? trimmed.toLowerCase() : undefined;
   },
-  z.enum(["exa", "searxng"]).default("exa")
+  z.enum(["exa", "searxng", "brave"]).default("exa")
 );
 
 const BooleanFlagSchema = z.preprocess((value) => {
@@ -66,10 +66,12 @@ const EnvSchema = z.object({
   OPENAI_API_KEY: z.string().optional(),
   ANTHROPIC_API_KEY: z.string().optional(),
   XAI_API_KEY: z.string().optional(),
+  GEMINI_API_KEY: z.string().optional(),
   HERMES_AGENT_API_BASE_URL: HermesAgentApiBaseUrlSchema,
   HERMES_AGENT_API_KEY: OptionalTrimmedStringSchema,
   HERMES_AGENT_MODEL: OptionalTrimmedStringSchema,
   EXA_API_KEY: z.string().optional(),
+  BRAVE_SEARCH_API_KEY: OptionalTrimmedStringSchema,
 
   // Chat-mode web_search tool configuration. Search mode remains Exa-only for now.
   CHAT_WEB_SEARCH_ENGINE: ChatWebSearchEngineSchema,
@@ -99,6 +101,14 @@ const EnvSchema = z.object({
     });
   }
 
+  if (value.CHAT_WEB_SEARCH_ENGINE === "brave" && !value.BRAVE_SEARCH_API_KEY) {
+    ctx.addIssue({
+      code: "custom",
+      path: ["BRAVE_SEARCH_API_KEY"],
+      message: "BRAVE_SEARCH_API_KEY is required when CHAT_WEB_SEARCH_ENGINE=brave",
+    });
+  }
+
   if ((value.CHAT_CODEX_TOOL_ENABLED || value.CHAT_SHELL_TOOL_ENABLED) && !value.CHAT_CODEX_REMOTE_HOST) {
     ctx.addIssue({
       code: "custom",

server/src/llm/chat-tools.ts

@@ -7,6 +7,7 @@ import { convert as htmlToText } from "html-to-text";
 import { z } from "zod";
 import { buildBrowserLikeNavigationHeaders } from "../browser-fetch-headers.js";
 import { env } from "../env.js";
+import { searchBrave } from "../search/brave.js";
 import { exaClient } from "../search/exa.js";
 import { searchSearxng } from "../search/searxng.js";
 import type { ChatMessage } from "./types.js";
@@ -507,11 +508,33 @@ async function runSearxngWebSearchTool(args: WebSearchArgs): Promise<ToolRunOutc
   };
 }
 
+async function runBraveWebSearchTool(args: WebSearchArgs): Promise<ToolRunOutcome> {
+  const response = await searchBrave(args.query, {
+    numResults: args.numResults ?? DEFAULT_WEB_RESULTS,
+    includeDomains: args.includeDomains,
+    excludeDomains: args.excludeDomains,
+  });
+
+  return {
+    ok: true,
+    searchEngine: "brave",
+    query: args.query,
+    requestId: response.requestId,
+    results: response.results.map((result, index) => ({
+      rank: index + 1,
+      ...result,
+    })),
+  };
+}
+
 async function runWebSearchTool(input: unknown): Promise<ToolRunOutcome> {
   const args = WebSearchArgsSchema.parse(input);
   if (env.CHAT_WEB_SEARCH_ENGINE === "searxng") {
     return runSearxngWebSearchTool(args);
   }
+  if (env.CHAT_WEB_SEARCH_ENGINE === "brave") {
+    return runBraveWebSearchTool(args);
+  }
   return runExaWebSearchTool(args);
 }
 

server/src/llm/protocols/gemini-api.ts

@@ -0,0 +1,501 @@
+import {
+  buildChatToolSystemPrompt,
+  executeToolCallAndBuildEvent,
+  getEnabledChatTools,
+  getUnstreamedText,
+  looksLikeDanglingToolIntent,
+  MAX_DANGLING_TOOL_INTENT_RETRIES,
+  MAX_TOOL_ROUNDS,
+  prepareToolCallExecution,
+  type NormalizedToolCall,
+  type ToolAwareCompletionParams,
+  type ToolAwareCompletionResult,
+  type ToolAwareStreamingEvent,
+  type ToolAwareUsage,
+  type ToolExecutionEvent,
+} from "../chat-tools.js";
+import {
+  buildImageSummaryText,
+  buildTextAttachmentPrompt,
+  buildTopLevelSystemPrompt,
+  getImageAttachments,
+  getTextAttachments,
+  parseImageDataUrl,
+} from "../message-content.js";
+import type { ChatMessage } from "../types.js";
+
+type GeminiClient = {
+  apiKey: string;
+  baseURL: string;
+};
+
+const INTERNAL_CORRECTION =
+  "Internal correction: the previous assistant message claimed it would run a tool, but no tool call was made. If the task needs an available tool, call it now. Otherwise provide the final answer directly without saying you will run a tool.";
+
+function normalizeModelResourceName(model: string) {
+  const trimmed = model.trim().replace(/^\/+/, "");
+  return trimmed.startsWith("models/") || trimmed.startsWith("tunedModels/") ? trimmed : `models/${trimmed}`;
+}
+
+function geminiUrl(client: GeminiClient, model: string, method: "generateContent" | "streamGenerateContent", extraParams: Record<string, string> = {}) {
+  const url = new URL(`${client.baseURL.replace(/\/+$/, "")}/${normalizeModelResourceName(model)}:${method}`);
+  url.searchParams.set("key", client.apiKey);
+  for (const [key, value] of Object.entries(extraParams)) {
+    url.searchParams.set(key, value);
+  }
+  return url;
+}
+
+function generationConfig(params: Pick<ToolAwareCompletionParams, "temperature" | "maxTokens">) {
+  const config: Record<string, unknown> = {};
+  if (params.temperature !== undefined) config.temperature = params.temperature;
+  if (params.maxTokens !== undefined) config.maxOutputTokens = params.maxTokens;
+  return Object.keys(config).length ? config : undefined;
+}
+
+function toGeminiJsonSchema(schema: unknown): Record<string, unknown> | undefined {
+  if (!schema || typeof schema !== "object" || Array.isArray(schema)) return undefined;
+  const input = schema as Record<string, unknown>;
+  const output: Record<string, unknown> = {};
+
+  if (typeof input.type === "string") output.type = input.type;
+  if (typeof input.description === "string") output.description = input.description;
+  if (typeof input.format === "string") output.format = input.format;
+  if (typeof input.nullable === "boolean") output.nullable = input.nullable;
+  if (Array.isArray(input.enum)) output.enum = input.enum.filter((value) => typeof value === "string");
+  if (Array.isArray(input.required)) output.required = input.required.filter((value) => typeof value === "string");
+
+  const items = toGeminiJsonSchema(input.items);
+  if (items) output.items = items;
+
+  if (input.properties && typeof input.properties === "object" && !Array.isArray(input.properties)) {
+    const properties: Record<string, unknown> = {};
+    for (const [key, value] of Object.entries(input.properties)) {
+      const propertySchema = toGeminiJsonSchema(value);
+      if (propertySchema) properties[key] = propertySchema;
+    }
+    if (Object.keys(properties).length) output.properties = properties;
+  }
+
+  return Object.keys(output).length ? output : undefined;
+}
+
+function toGeminiTools(tools: any[]) {
+  const functionDeclarations = tools
+    .map((tool) => {
+      if (tool?.type !== "function") return null;
+      const declaration: Record<string, unknown> = {
+        name: tool.function.name,
+        description: tool.function.description,
+      };
+      const parameters = toGeminiJsonSchema(tool.function.parameters);
+      if (parameters) declaration.parameters = parameters;
+      return declaration;
+    })
+    .filter(Boolean);
+
+  return functionDeclarations.length ? [{ functionDeclarations }] : undefined;
+}
+
+function toContentParts(message: ChatMessage) {
+  const imageAttachments = getImageAttachments(message);
+  const textAttachments = getTextAttachments(message);
+  const parts: Array<Record<string, unknown>> = [];
+
+  for (const attachment of imageAttachments) {
+    const source = parseImageDataUrl(attachment);
+    parts.push({
+      inlineData: {
+        mimeType: source.mediaType,
+        data: source.data,
+      },
+    });
+  }
+
+  const imageSummary = buildImageSummaryText(imageAttachments);
+  if (imageSummary) {
+    parts.push({ text: imageSummary });
+  }
+
+  for (const attachment of textAttachments) {
+    parts.push({ text: buildTextAttachmentPrompt(attachment) });
+  }
+
+  if (message.content.trim()) {
+    parts.push({ text: message.content });
+  }
+
+  return parts.length ? parts : [{ text: "" }];
+}
+
+function buildConversationContent(message: ChatMessage) {
+  if (message.role === "system") {
+    throw new Error("System messages must be handled separately for Gemini.");
+  }
+
+  if (message.role === "tool") {
+    const name = message.name?.trim() || "tool";
+    return {
+      role: "user",
+      parts: [{ text: `Tool output (${name}):\n${message.content}` }],
+    };
+  }
+
+  return {
+    role: message.role === "assistant" ? "model" : "user",
+    parts: toContentParts(message),
+  };
+}
+
+function buildBaseContents(messages: ChatMessage[]) {
+  return messages.filter((message) => message.role !== "system").map((message) => buildConversationContent(message));
+}
+
+function buildSystemInstruction(params: ToolAwareCompletionParams, toolSystemPrompt?: string) {
+  const text = buildTopLevelSystemPrompt(params.messages, params.userLocation, toolSystemPrompt);
+  return text ? { parts: [{ text }] } : undefined;
+}
+
+function mergeUsage(acc: Required<ToolAwareUsage>, usage: any) {
+  const normalized = normalizeUsage(usage);
+  if (!normalized) return false;
+  acc.inputTokens += normalized.inputTokens;
+  acc.outputTokens += normalized.outputTokens;
+  acc.totalTokens += normalized.totalTokens;
+  return true;
+}
+
+function normalizeUsage(usage: any) {
+  if (!usage) return null;
+  const inputTokens = usage.promptTokenCount ?? 0;
+  const outputTokens = usage.candidatesTokenCount ?? 0;
+  const totalTokens = usage.totalTokenCount ?? inputTokens + outputTokens;
+  return { inputTokens, outputTokens, totalTokens };
+}
+
+function getCandidate(response: any) {
+  return Array.isArray(response?.candidates) ? response.candidates[0] : null;
+}
+
+function getParts(response: any) {
+  const parts = getCandidate(response)?.content?.parts;
+  return Array.isArray(parts) ? parts : [];
+}
+
+function extractText(response: any) {
+  return getParts(response)
+    .map((part: any) => (typeof part?.text === "string" ? part.text : ""))
+    .join("");
+}
+
+function stringifyToolArgs(args: unknown) {
+  try {
+    return JSON.stringify(args ?? {});
+  } catch {
+    return "{}";
+  }
+}
+
+function normalizeToolCallsFromParts(parts: any[], round: number): NormalizedToolCall[] {
+  return parts
+    .filter((part) => part?.functionCall)
+    .map((part, index) => ({
+      id: part.functionCall.id ?? `tool_call_${round}_${index}`,
+      name: part.functionCall.name ?? "unknown_tool",
+      arguments: stringifyToolArgs(part.functionCall.args),
+    }));
+}
+
+function buildFunctionResponsePart(call: NormalizedToolCall, toolResult: unknown) {
+  return {
+    functionResponse: {
+      id: call.id,
+      name: call.name,
+      response: toolResult,
+    },
+  };
+}
+
+function appendCorrection(conversation: any[], text: string) {
+  conversation.push({ role: "model", parts: [{ text }] });
+  conversation.push({ role: "user", parts: [{ text: INTERNAL_CORRECTION }] });
+}
+
+async function parseGeminiResponse(response: Response) {
+  const bodyText = await response.text();
+  let body: any = null;
+  try {
+    body = bodyText ? JSON.parse(bodyText) : null;
+  } catch {
+    body = { raw: bodyText };
+  }
+
+  if (!response.ok) {
+    throw new Error(body?.error?.message ?? `Gemini API request failed with status ${response.status}.`);
+  }
+
+  return body;
+}
+
+async function generateContent(params: ToolAwareCompletionParams, body: Record<string, unknown>) {
+  const response = await fetch(geminiUrl(params.client, params.model, "generateContent"), {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+  return parseGeminiResponse(response);
+}
+
+function getFailureMessage(response: any, text: string, toolCallCount: number) {
+  const promptBlockReason = response?.promptFeedback?.blockReason;
+  if (promptBlockReason) return `Gemini prompt blocked: ${promptBlockReason}.`;
+
+  const candidate = getCandidate(response);
+  const finishReason = candidate?.finishReason;
+  if (!finishReason || finishReason === "STOP" || finishReason === "MAX_TOKENS") return null;
+  if (text || toolCallCount > 0) return null;
+  return candidate?.finishMessage ?? `Gemini response stopped: ${finishReason}.`;
+}
+
+function buildRequest(params: ToolAwareCompletionParams, conversation: any[], enabledTools: any[] = []) {
+  const tools = toGeminiTools(enabledTools);
+  return {
+    contents: conversation,
+    systemInstruction: buildSystemInstruction(params, enabledTools.length ? buildChatToolSystemPrompt(params) : undefined),
+    generationConfig: generationConfig(params),
+    tools,
+    toolConfig: tools ? { functionCallingConfig: { mode: "AUTO" } } : undefined,
+  };
+}
+
+export async function completeWithGeminiApi(params: ToolAwareCompletionParams): Promise<ToolAwareCompletionResult> {
+  const enabledTools = getEnabledChatTools(params);
+  const conversation = buildBaseContents(params.messages);
+  const rawResponses: unknown[] = [];
+  const toolEvents: ToolExecutionEvent[] = [];
+  const usageAcc: Required<ToolAwareUsage> = { inputTokens: 0, outputTokens: 0, totalTokens: 0 };
+  let sawUsage = false;
+  let totalToolCalls = 0;
+  let danglingToolIntentRetries = 0;
+
+  for (let round = 0; round < MAX_TOOL_ROUNDS; round += 1) {
+    const response = await generateContent(params, buildRequest(params, conversation, enabledTools));
+    rawResponses.push(response);
+    sawUsage = mergeUsage(usageAcc, response?.usageMetadata) || sawUsage;
+
+    const parts = getParts(response);
+    const text = extractText(response);
+    const normalizedToolCalls = normalizeToolCallsFromParts(parts, round);
+    const failureMessage = getFailureMessage(response, text, normalizedToolCalls.length);
+    if (failureMessage) throw new Error(failureMessage);
+
+    if (!normalizedToolCalls.length) {
+      if (danglingToolIntentRetries < MAX_DANGLING_TOOL_INTENT_RETRIES && looksLikeDanglingToolIntent(text)) {
+        danglingToolIntentRetries += 1;
+        appendCorrection(conversation, text);
+        continue;
+      }
+      return {
+        text,
+        usage: sawUsage ? usageAcc : undefined,
+        raw: { responses: rawResponses, toolCallsUsed: totalToolCalls, api: "gemini.generateContent" },
+        toolEvents,
+      };
+    }
+
+    totalToolCalls += normalizedToolCalls.length;
+    conversation.push({ role: "model", parts });
+
+    const toolResultParts: any[] = [];
+    for (const call of normalizedToolCalls) {
+      const { execution } = prepareToolCallExecution(call);
+      const { event, toolResult } = await executeToolCallAndBuildEvent(call, execution, params);
+      toolEvents.push(event);
+      toolResultParts.push(buildFunctionResponsePart(call, toolResult));
+    }
+
+    conversation.push({ role: "user", parts: toolResultParts });
+  }
+
+  return {
+    text: "I reached the tool-call limit while gathering information. Please narrow the request and try again.",
+    usage: sawUsage ? usageAcc : undefined,
+    raw: { responses: rawResponses, toolCallsUsed: totalToolCalls, toolCallLimitReached: true, api: "gemini.generateContent" },
+    toolEvents,
+  };
+}
+
+function findSseBoundary(buffer: string) {
+  const crlf = buffer.indexOf("\r\n\r\n");
+  const lf = buffer.indexOf("\n\n");
+  if (crlf === -1) return lf === -1 ? null : { index: lf, length: 2 };
+  if (lf === -1) return { index: crlf, length: 4 };
+  return crlf < lf ? { index: crlf, length: 4 } : { index: lf, length: 2 };
+}
+
+function parseSseEvent(rawEvent: string) {
+  const data = rawEvent
+    .split(/\r?\n/)
+    .filter((line) => line.startsWith("data:"))
+    .map((line) => line.slice("data:".length).trimStart())
+    .join("\n")
+    .trim();
+  if (!data || data === "[DONE]") return null;
+  return JSON.parse(data);
+}
+
+async function* streamGeminiResponses(params: ToolAwareCompletionParams, body: Record<string, unknown>) {
+  const response = await fetch(geminiUrl(params.client, params.model, "streamGenerateContent", { alt: "sse" }), {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(body),
+  });
+
+  if (!response.ok) {
+    await parseGeminiResponse(response);
+    return;
+  }
+
+  if (!response.body) {
+    throw new Error("Gemini stream response did not include a body.");
+  }
+
+  const reader = response.body.getReader();
+  const decoder = new TextDecoder();
+  let buffer = "";
+
+  while (true) {
+    const { value, done } = await reader.read();
+    if (done) break;
+    buffer += decoder.decode(value, { stream: true });
+    let boundary = findSseBoundary(buffer);
+    while (boundary) {
+      const rawEvent = buffer.slice(0, boundary.index);
+      buffer = buffer.slice(boundary.index + boundary.length);
+      const event = parseSseEvent(rawEvent);
+      if (event) yield event;
+      boundary = findSseBoundary(buffer);
+    }
+  }
+
+  buffer += decoder.decode();
+  const tail = buffer.trim();
+  if (tail) {
+    const event = parseSseEvent(tail);
+    if (event) yield event;
+  }
+}
+
+export async function* streamWithGeminiApi(params: ToolAwareCompletionParams): AsyncGenerator<ToolAwareStreamingEvent> {
+  const enabledTools = getEnabledChatTools(params);
+  const conversation = buildBaseContents(params.messages);
+  const rawResponses: unknown[] = [];
+  const toolEvents: ToolExecutionEvent[] = [];
+  const usageAcc: Required<ToolAwareUsage> = { inputTokens: 0, outputTokens: 0, totalTokens: 0 };
+  let sawUsage = false;
+  let totalToolCalls = 0;
+  let danglingToolIntentRetries = 0;
+
+  if (!enabledTools.length) {
+    let text = "";
+    let latestUsage: any = null;
+    for await (const response of streamGeminiResponses(params, buildRequest(params, conversation))) {
+      rawResponses.push(response);
+      if (response?.usageMetadata) latestUsage = response.usageMetadata;
+      const failureMessage = getFailureMessage(response, extractText(response), 0);
+      if (failureMessage) throw new Error(failureMessage);
+      const delta = extractText(response);
+      if (delta) {
+        text += delta;
+        yield { type: "delta", text: delta };
+      }
+    }
+
+    sawUsage = mergeUsage(usageAcc, latestUsage) || sawUsage;
+
+    yield {
+      type: "done",
+      result: {
+        text,
+        usage: sawUsage ? usageAcc : undefined,
+        raw: { streamed: true, responses: rawResponses, toolCallsUsed: 0, api: "gemini.streamGenerateContent" },
+        toolEvents: [],
+      },
+    };
+    return;
+  }
+
+  for (let round = 0; round < MAX_TOOL_ROUNDS; round += 1) {
+    const roundParts: any[] = [];
+    let roundText = "";
+    let latestRoundResponse: any = null;
+    let latestRoundUsage: any = null;
+
+    for await (const response of streamGeminiResponses(params, buildRequest(params, conversation, enabledTools))) {
+      rawResponses.push(response);
+      latestRoundResponse = response;
+      if (response?.usageMetadata) latestRoundUsage = response.usageMetadata;
+      roundParts.push(...getParts(response));
+      roundText += extractText(response);
+    }
+
+    sawUsage = mergeUsage(usageAcc, latestRoundUsage) || sawUsage;
+
+    const normalizedToolCalls = normalizeToolCallsFromParts(roundParts, round);
+    const failureMessage = getFailureMessage(latestRoundResponse ?? { candidates: [{ content: { parts: roundParts } }] }, roundText, normalizedToolCalls.length);
+    if (failureMessage) throw new Error(failureMessage);
+
+    if (!normalizedToolCalls.length) {
+      if (danglingToolIntentRetries < MAX_DANGLING_TOOL_INTENT_RETRIES && looksLikeDanglingToolIntent(roundText)) {
+        danglingToolIntentRetries += 1;
+        appendCorrection(conversation, roundText);
+        continue;
+      }
+      const unstreamedText = getUnstreamedText(roundText, "");
+      if (unstreamedText) {
+        yield { type: "delta", text: unstreamedText };
+      }
+      yield {
+        type: "done",
+        result: {
+          text: roundText,
+          usage: sawUsage ? usageAcc : undefined,
+          raw: { streamed: true, responses: rawResponses, toolCallsUsed: totalToolCalls, api: "gemini.streamGenerateContent" },
+          toolEvents,
+        },
+      };
+      return;
+    }
+
+    totalToolCalls += normalizedToolCalls.length;
+    conversation.push({ role: "model", parts: roundParts });
+
+    const toolResultParts: any[] = [];
+    for (const call of normalizedToolCalls) {
+      const { event: initiatedEvent, execution } = prepareToolCallExecution(call);
+      yield { type: "tool_call", event: initiatedEvent };
+      const { event, toolResult } = await executeToolCallAndBuildEvent(call, execution, params);
+      toolEvents.push(event);
+      yield { type: "tool_call", event };
+      toolResultParts.push(buildFunctionResponsePart(call, toolResult));
+    }
+
+    conversation.push({ role: "user", parts: toolResultParts });
+  }
+
+  yield {
+    type: "done",
+    result: {
+      text: "I reached the tool-call limit while gathering information. Please narrow the request and try again.",
+      usage: sawUsage ? usageAcc : undefined,
+      raw: {
+        streamed: true,
+        responses: rawResponses,
+        toolCallsUsed: totalToolCalls,
+        toolCallLimitReached: true,
+        api: "gemini.streamGenerateContent",
+      },
+      toolEvents,
+    },
+  };
+}

server/src/llm/provider-adapters.ts

@@ -5,10 +5,11 @@ import {
   type ToolAwareStreamingEvent,
 } from "./chat-tools.js";
 import { completeWithChatCompletionsApi, streamWithChatCompletionsApi } from "./protocols/chat-completions-api.js";
+import { completeWithGeminiApi, streamWithGeminiApi } from "./protocols/gemini-api.js";
 import { completeWithMessagesApi, streamWithMessagesApi } from "./protocols/messages-api.js";
 import { completeWithResponsesApi, streamWithResponsesApi } from "./protocols/responses-api.js";
 import { env } from "../env.js";
-import { anthropicClient, hermesAgentClient, isHermesAgentConfigured, openaiClient, xaiClient } from "./providers.js";
+import { anthropicClient, geminiClient, hermesAgentClient, isHermesAgentConfigured, openaiClient, xaiClient } from "./providers.js";
 import type { ChatMessage, Provider } from "./types.js";
 
 type ProviderAdapterParams = {
@@ -27,7 +28,7 @@ export type ProviderChatAdapter = {
   stream(params: ProviderAdapterParams): AsyncGenerator<ToolAwareStreamingEvent>;
 };
 
-type ChatProtocolId = "chat-completions" | "messages" | "responses";
+type ChatProtocolId = "chat-completions" | "gemini" | "messages" | "responses";
 
 type ChatProtocol = {
   id: ChatProtocolId;
@@ -39,6 +40,7 @@ type ModelCatalogSpec = {
   enabled?: () => boolean;
   fetchModels(client: any): Promise<string[]>;
   fallbackModels?: () => string[];
+  sortModels?: (models: string[]) => string[];
 };
 
 type ProviderBackendSpec = {
@@ -61,6 +63,12 @@ const messagesProtocol: ChatProtocol = {
   stream: streamWithMessagesApi,
 };
 
+const geminiProtocol: ChatProtocol = {
+  id: "gemini",
+  complete: completeWithGeminiApi,
+  stream: streamWithGeminiApi,
+};
+
 const responsesProtocol: ChatProtocol = {
   id: "responses",
   complete: completeWithResponsesApi,
@@ -77,6 +85,10 @@ function modelIdsFromListResponse(page: any) {
     : [];
 }
 
+function stripModelResourcePrefix(model: string) {
+  return model.startsWith("models/") ? model.slice("models/".length) : model;
+}
+
 function isLikelyResponsesApiModel(model: string) {
   const id = model.toLowerCase();
   if (id.includes("embedding") || id.includes("moderation")) return false;
@@ -86,6 +98,37 @@ function isLikelyResponsesApiModel(model: string) {
   return /^(gpt-|o\d|chatgpt-)/.test(id);
 }
 
+function isLikelyGeminiChatModel(model: string) {
+  const id = model.toLowerCase();
+  if (!id.startsWith("gemini-")) return false;
+  if (id.includes("embedding") || id.includes("embed")) return false;
+  if (id.includes("image") || id.includes("imagen") || id.includes("veo")) return false;
+  if (id.includes("audio") || id.includes("tts") || id.includes("live")) return false;
+  if (id.includes("computer-use") || id.includes("robotics")) return false;
+  return true;
+}
+
+function preferGeminiModels(models: string[]) {
+  const preferred = [
+    "gemini-3.5-flash",
+    "gemini-flash-latest",
+    "gemini-3.1-flash-lite",
+    "gemini-3-flash-preview",
+    "gemini-pro-latest",
+  ];
+  const modelSet = new Set(models);
+  return [...preferred.filter((model) => modelSet.delete(model)), ...[...modelSet].sort((a, b) => a.localeCompare(b))];
+}
+
+async function fetchJson(url: URL): Promise<any> {
+  const response = await fetch(url);
+  const body: any = await response.json().catch(() => null);
+  if (!response.ok) {
+    throw new Error(body?.error?.message ?? `Gemini model fetch failed with status ${response.status}.`);
+  }
+  return body;
+}
+
 function withClient(params: ProviderAdapterParams, client: any, enabledTools?: string[]): ToolAwareCompletionParams {
   return {
     client,
@@ -160,6 +203,29 @@ const backendSpecs: Record<Provider, ProviderBackendSpec> = {
       },
     },
   },
+  gemini: {
+    createClient: geminiClient,
+    plainProtocol: geminiProtocol,
+    toolProtocol: geminiProtocol,
+    managedTools: true,
+    modelCatalog: {
+      async fetchModels(client) {
+        const url = new URL(`${client.baseURL.replace(/\/+$/, "")}/models`);
+        url.searchParams.set("key", client.apiKey);
+        url.searchParams.set("pageSize", "1000");
+        const page = await fetchJson(url);
+        return Array.isArray(page?.models)
+          ? page.models
+              .filter((model: any) => Array.isArray(model?.supportedGenerationMethods) && model.supportedGenerationMethods.includes("generateContent"))
+              .map((model: any) => model?.name)
+              .filter((id: unknown): id is string => typeof id === "string")
+              .map(stripModelResourcePrefix)
+              .filter(isLikelyGeminiChatModel)
+          : [];
+      },
+      sortModels: preferGeminiModels,
+    },
+  },
   "hermes-agent": {
     createClient: hermesAgentClient,
     plainProtocol: chatCompletionsProtocol,
@@ -209,7 +275,8 @@ export function listModelCatalogProviders(): Provider[] {
 export async function fetchProviderCatalogModels(provider: Provider) {
   const spec = backendSpecs[provider].modelCatalog;
   if (!spec) return [];
-  return uniqSorted(await spec.fetchModels(backendSpecs[provider].createClient()));
+  const models = uniqSorted(await spec.fetchModels(backendSpecs[provider].createClient()));
+  return spec.sortModels ? spec.sortModels(models) : models;
 }
 
 export function getProviderCatalogFallbackModels(provider: Provider) {

server/src/llm/provider-ids.ts

@@ -6,6 +6,7 @@ const apiToPrismaProvider = {
   openai: "openai",
   anthropic: "anthropic",
   xai: "xai",
+  gemini: "gemini",
   "hermes-agent": "hermes_agent",
 } as const satisfies Record<Provider, PrismaProvider>;
 
@@ -13,6 +14,7 @@ const prismaToApiProvider = {
   openai: "openai",
   anthropic: "anthropic",
   xai: "xai",
+  gemini: "gemini",
   hermes_agent: "hermes-agent",
   "hermes-agent": "hermes-agent",
 } as const satisfies Record<PrismaProvider | "hermes-agent", Provider>;

server/src/llm/providers.ts

@@ -1,5 +1,5 @@
-import OpenAI from "openai";
 import Anthropic from "@anthropic-ai/sdk";
+import OpenAI from "openai";
 import { env } from "../env.js";
 
 export function openaiClient() {
@@ -13,6 +13,14 @@ export function xaiClient() {
   return new OpenAI({ apiKey: env.XAI_API_KEY, baseURL: "https://api.x.ai/v1" });
 }
 
+export function geminiClient() {
+  if (!env.GEMINI_API_KEY) throw new Error("GEMINI_API_KEY not set");
+  return {
+    apiKey: env.GEMINI_API_KEY,
+    baseURL: "https://generativelanguage.googleapis.com/v1beta",
+  };
+}
+
 export function isHermesAgentConfigured() {
   return Boolean(env.HERMES_AGENT_API_KEY);
 }

server/src/llm/streaming.ts

@@ -119,7 +119,12 @@ export async function* runMultiplexStream(req: MultiplexRequest): AsyncGenerator
     if (shouldPersist && chatId && call) {
       await prisma.$transaction(async (tx) => {
         await tx.message.create({
-          data: { chatId, role: "assistant" as any, content: text },
+          data: {
+            chatId,
+            role: "assistant" as any,
+            content: text,
+            metadata: req.clientRequestId ? ({ clientRequestId: req.clientRequestId } as any) : undefined,
+          },
         });
         await tx.llmCall.update({
           where: { id: call.id },

server/src/llm/types.ts

@@ -1,4 +1,4 @@
-export const PROVIDERS = ["openai", "anthropic", "xai", "hermes-agent"] as const;
+export const PROVIDERS = ["openai", "anthropic", "xai", "gemini", "hermes-agent"] as const;
 
 export type Provider = (typeof PROVIDERS)[number];
 
@@ -33,6 +33,7 @@ export type ChatMessage = {
 export type MultiplexRequest = {
   chatId?: string;
   persist?: boolean;
+  clientRequestId?: string;
   provider: Provider;
   model: string;
   messages: ChatMessage[];

server/src/routes.ts

@@ -1,3 +1,4 @@
+import { randomUUID } from "node:crypto";
 import { performance } from "node:perf_hooks";
 import { z } from "zod";
 import type { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
@@ -16,8 +17,9 @@ import { exaClient } from "./search/exa.js";
 import { isFreshSearchCacheHit, normalizeSearchQuery } from "./search-cache.js";
 import type { ChatAttachment } from "./llm/types.js";
 
-const ProviderSchema = z.enum(["openai", "anthropic", "xai", "hermes-agent"]);
+const ProviderSchema = z.enum(["openai", "anthropic", "xai", "gemini", "hermes-agent"]);
 const MAX_ADDITIONAL_SYSTEM_PROMPT_CHARS = 12_000;
+const MAX_FORK_MESSAGE_SNIPPET_CHARS = 48;
 const EnabledToolsSchema = z.array(z.string().trim().min(1).max(80)).max(20).transform((value) => normalizeEnabledChatTools(value));
 
 type IncomingChatMessage = {
@@ -88,13 +90,13 @@ function withRequestUserLocation<T extends { userLocation?: string }>(body: T, r
   return body.userLocation ? body : { ...body, userLocation: inferRequestUserLocation(req) };
 }
 
-async function storeNonAssistantMessages(chatId: string, messages: IncomingChatMessage[]) {
+async function storeNonAssistantMessages(chatId: string, messages: IncomingChatMessage[], clientRequestId?: string) {
   const incoming = messages.filter((m) => m.role !== "assistant");
   if (!incoming.length) return;
 
   const existing = await prisma.message.findMany({
     where: { chatId },
-    orderBy: { createdAt: "asc" },
+    orderBy: [{ createdAt: "asc" }, { id: "asc" }],
     select: { role: true, content: true, name: true, metadata: true },
   });
   const existingNonAssistant = existing.filter((m) => m.role !== "assistant" && !isToolCallLogMessage(m));
@@ -109,14 +111,21 @@ async function storeNonAssistantMessages(chatId: string, messages: IncomingChatM
   const toInsert = sharedPrefix === existingNonAssistant.length ? incoming.slice(existingNonAssistant.length) : incoming;
   if (!toInsert.length) return;
 
+  const finalUserMessageIndex = toInsert.map((message) => message.role).lastIndexOf("user");
   await prisma.message.createMany({
-    data: toInsert.map((m) => ({
-      chatId,
-      role: m.role as any,
-      content: m.content,
-      name: m.name,
-      metadata: m.attachments?.length ? ({ attachments: m.attachments } as any) : undefined,
-    })),
+    data: toInsert.map((m, index) => {
+      const metadata = {
+        ...(m.attachments?.length ? { attachments: m.attachments } : {}),
+        ...(clientRequestId && index === finalUserMessageIndex ? { clientRequestId } : {}),
+      };
+      return {
+        chatId,
+        role: m.role as any,
+        content: m.content,
+        name: m.name,
+        metadata: Object.keys(metadata).length ? (metadata as any) : undefined,
+      };
+    }),
   });
 }
 
@@ -169,6 +178,7 @@ const CompletionStreamBody = z
   .object({
     chatId: z.string().optional(),
     persist: z.boolean().optional(),
+    clientRequestId: z.string().trim().min(1).max(128).optional(),
     provider: ProviderSchema,
     model: z.string().min(1),
     messages: z.array(CompletionMessageSchema),
@@ -186,6 +196,13 @@ const CompletionStreamBody = z
         path: ["chatId"],
       });
     }
+    if (value.clientRequestId && (value.persist === false || !value.chatId)) {
+      ctx.addIssue({
+        code: z.ZodIssueCode.custom,
+        message: "clientRequestId requires a persisted stream with chatId",
+        path: ["clientRequestId"],
+      });
+    }
   });
 
 function mergeAttachmentsIntoMetadata(metadata: unknown, attachments?: ChatAttachment[]) {
@@ -302,6 +319,21 @@ function normalizeSuggestedTitle(raw: string, fallback: string) {
   return words.slice(0, 4).join(" ").slice(0, 64).trim() || fallback;
 }
 
+export function buildForkTitle(originalTitle: string | null, messageContent?: string) {
+  if (messageContent !== undefined) {
+    const snippet = truncateContextPart(messageContent.replace(/\s+/g, " "), MAX_FORK_MESSAGE_SNIPPET_CHARS) ?? "message";
+    return `Fork of '${snippet}'`;
+  }
+  return `Fork of ${originalTitle?.trim() || "Untitled chat"}`;
+}
+
+export function copyForkMessageMetadata(metadata: unknown) {
+  if (metadata === null || metadata === undefined) return undefined;
+  if (typeof metadata !== "object" || Array.isArray(metadata)) return metadata;
+  const { clientRequestId: _clientRequestId, ...copied } = metadata as Record<string, unknown>;
+  return Object.keys(copied).length ? copied : undefined;
+}
+
 async function generateChatTitle(content: string) {
   const systemPrompt =
     "You create short chat titles. Return exactly one line, maximum 4 words, no quotes, no trailing punctuation.";
@@ -399,6 +431,8 @@ function buildSseHeaders(originHeader: string | undefined) {
 type SearchRunRequest = z.infer<typeof SearchRunBody>;
 
 const activeChatStreams = new Map<string, ActiveSseStream>();
+const activeChatStreamRequestIds = new Map<string, string>();
+const chatDeletionRoots = new Set<string>();
 const activeSearchStreams = new Map<string, ActiveSseStream>();
 const STARRED_PROJECT_ID = "starred";
 
@@ -411,6 +445,8 @@ const starredProjectItemsSelect = {
 const chatSummarySelect = {
   id: true,
   title: true,
+  titleGenerationPending: true,
+  parentChatId: true,
   createdAt: true,
   updatedAt: true,
   initiatedProvider: true,
@@ -491,6 +527,29 @@ async function getSearchSummary(searchId: string) {
   return search ? serializeSearchLike(search) : null;
 }
 
+async function listRecentChatsWithRoots() {
+  const chats = await prisma.chat.findMany({
+    orderBy: { updatedAt: "desc" },
+    take: 100,
+    select: chatSummarySelect,
+  });
+  const includedIds = new Set(chats.map((chat) => chat.id));
+  const missingRootIds = [
+    ...new Set(
+      chats
+        .map((chat) => chat.parentChatId)
+        .filter((id): id is string => id !== null && !includedIds.has(id))
+    ),
+  ];
+  if (!missingRootIds.length) return chats;
+
+  const roots = await prisma.chat.findMany({
+    where: { id: { in: missingRootIds } },
+    select: chatSummarySelect,
+  });
+  return [...chats, ...roots].sort(compareUpdatedAtDesc);
+}
+
 async function setChatStarred(chatId: string, starred: boolean) {
   const exists = await prisma.chat.findUnique({ where: { id: chatId }, select: { id: true } });
   if (!exists) return null;
@@ -529,11 +588,7 @@ async function setSearchStarred(searchId: string, starred: boolean) {
 
 async function listWorkspaceItems() {
   const [chats, searches] = await Promise.all([
-    prisma.chat.findMany({
-      orderBy: { updatedAt: "desc" },
-      take: 100,
-      select: chatSummarySelect,
-    }),
+    listRecentChatsWithRoots(),
     prisma.search.findMany({
       orderBy: { updatedAt: "desc" },
       take: 100,
@@ -554,6 +609,7 @@ function writeSseEvent(reply: FastifyReply, event: SseStreamEvent) {
 }
 
 async function streamActiveRun(req: FastifyRequest, reply: FastifyReply, stream: ActiveSseStream) {
+  if (reply.raw.destroyed || reply.raw.writableEnded) return reply;
   reply.raw.writeHead(200, buildSseHeaders(typeof req.headers.origin === "string" ? req.headers.origin : undefined));
   reply.raw.flushHeaders?.();
 
@@ -588,10 +644,24 @@ function mapChatStreamEvent(ev: StreamEvent): SseStreamEvent {
   return { event: ev.type, data: ev };
 }
 
-function startActiveChatStream(chatId: string, body: z.infer<typeof CompletionStreamBody>) {
+export function registerActiveChatStream(chatId: string, clientRequestId?: string) {
   const stream = new ActiveSseStream();
   activeChatStreams.set(chatId, stream);
+  if (clientRequestId) {
+    activeChatStreamRequestIds.set(chatId, clientRequestId);
+  } else {
+    activeChatStreamRequestIds.delete(chatId);
+  }
+  return stream;
+}
 
+export function clearActiveChatStream(chatId: string, stream: ActiveSseStream) {
+  if (activeChatStreams.get(chatId) !== stream) return;
+  activeChatStreams.delete(chatId);
+  activeChatStreamRequestIds.delete(chatId);
+}
+
+function executeActiveChatStream(chatId: string, body: z.infer<typeof CompletionStreamBody>, stream: ActiveSseStream) {
   void (async () => {
     let sawTerminalEvent = false;
     try {
@@ -611,11 +681,46 @@ function startActiveChatStream(chatId: string, body: z.infer<typeof CompletionSt
     } catch (err) {
       stream.complete({ event: "error", data: { message: getErrorMessage(err) } });
     } finally {
-      activeChatStreams.delete(chatId);
+      clearActiveChatStream(chatId, stream);
     }
   })();
+}
 
-  return stream;
+function getMetadataClientRequestId(metadata: unknown) {
+  if (!metadata || typeof metadata !== "object" || Array.isArray(metadata)) return null;
+  const clientRequestId = (metadata as Record<string, unknown>).clientRequestId;
+  return typeof clientRequestId === "string" ? clientRequestId : null;
+}
+
+async function findCompletedChatSubmission(chatId: string, clientRequestId: string) {
+  const assistantMessages = await prisma.message.findMany({
+    where: { chatId, role: "assistant" as any },
+    orderBy: { createdAt: "desc" },
+    select: { content: true, metadata: true },
+  });
+  return assistantMessages.find((message) => getMetadataClientRequestId(message.metadata) === clientRequestId) ?? null;
+}
+
+function completeChatSubmissionStream(
+  stream: ActiveSseStream,
+  chatId: string,
+  body: z.infer<typeof CompletionStreamBody>,
+  assistantText: string
+) {
+  stream.emit("meta", {
+    type: "meta",
+    chatId,
+    callId: null,
+    provider: body.provider,
+    model: body.model,
+  });
+  stream.complete({
+    event: "done",
+    data: {
+      type: "done",
+      text: assistantText,
+    },
+  });
 }
 
 async function executeSearchRunStream(searchId: string, body: SearchRunRequest, stream: ActiveSseStream) {
@@ -816,11 +921,7 @@ export async function registerRoutes(app: FastifyInstance) {
 
   app.get("/v1/chats", async (req) => {
     requireAdmin(req);
-    const chats = await prisma.chat.findMany({
-      orderBy: { updatedAt: "desc" },
-      take: 100,
-      select: chatSummarySelect,
-    });
+    const chats = await listRecentChatsWithRoots();
     return { chats: chats.map((chat) => serializeChatLike(chat)) };
   });
 
@@ -879,6 +980,80 @@ export async function registerRoutes(app: FastifyInstance) {
     return { chat: serializeChatLike(chat) };
   });
 
+  app.post("/v1/chats/:chatId/fork", async (req) => {
+    requireAdmin(req);
+    const Params = z.object({ chatId: z.string() });
+    const Body = z.object({ messageId: z.string().trim().min(1).optional() });
+    const { chatId } = Params.parse(req.params);
+    const parsed = Body.safeParse(req.body ?? {});
+    if (!parsed.success) return app.httpErrors.badRequest(parsed.error.message);
+
+    const result = await prisma.$transaction(async (tx) => {
+      const source = await tx.chat.findUnique({
+        where: { id: chatId },
+        select: {
+          id: true,
+          title: true,
+          parentChatId: true,
+          initiatedProvider: true,
+          initiatedModel: true,
+          lastUsedProvider: true,
+          lastUsedModel: true,
+          additionalSystemPrompt: true,
+          enabledTools: true,
+          userId: true,
+          messages: { orderBy: [{ createdAt: "asc" }, { id: "asc" }] },
+        },
+      });
+      if (!source) return { status: "chat-not-found" as const };
+
+      let messages = source.messages;
+      let selectedMessage: (typeof source.messages)[number] | undefined;
+      if (parsed.data.messageId) {
+        const selectedIndex = messages.findIndex((message) => message.id === parsed.data.messageId);
+        if (selectedIndex < 0) return { status: "message-not-found" as const };
+        selectedMessage = messages[selectedIndex];
+        if (selectedMessage.role !== "assistant") return { status: "message-not-assistant" as const };
+        messages = messages.slice(0, selectedIndex + 1);
+      }
+
+      const forkMessageIdPrefix = `fork-${randomUUID()}`;
+      const chat = await tx.chat.create({
+        data: {
+          title: buildForkTitle(source.title, selectedMessage?.content),
+          titleGenerationPending: true,
+          parentChatId: source.parentChatId ?? source.id,
+          initiatedProvider: source.initiatedProvider,
+          initiatedModel: source.initiatedModel,
+          lastUsedProvider: source.lastUsedProvider,
+          lastUsedModel: source.lastUsedModel,
+          additionalSystemPrompt: source.additionalSystemPrompt,
+          enabledTools: (source.enabledTools ?? undefined) as any,
+          userId: source.userId,
+          messages: messages.length
+            ? {
+                create: messages.map((message, index) => ({
+                  id: `${forkMessageIdPrefix}-${String(index).padStart(8, "0")}`,
+                  createdAt: message.createdAt,
+                  role: message.role,
+                  content: message.content,
+                  name: message.name,
+                  metadata: copyForkMessageMetadata(message.metadata) as any,
+                })),
+              }
+            : undefined,
+        },
+        select: chatSummarySelect,
+      });
+      return { status: "created" as const, chat };
+    });
+
+    if (result.status === "chat-not-found") return app.httpErrors.notFound("chat not found");
+    if (result.status === "message-not-found") return app.httpErrors.notFound("message not found in chat");
+    if (result.status === "message-not-assistant") return app.httpErrors.badRequest("fork message must be an assistant response");
+    return { chat: serializeChatLike(result.chat) };
+  });
+
   app.patch("/v1/chats/:chatId", async (req) => {
     requireAdmin(req);
     const Params = z.object({ chatId: z.string() });
@@ -891,7 +1066,10 @@ export async function registerRoutes(app: FastifyInstance) {
     const body = Body.parse(req.body ?? {});
 
     const data: Record<string, unknown> = {};
-    if (body.title !== undefined) data.title = body.title;
+    if (body.title !== undefined) {
+      data.title = body.title;
+      data.titleGenerationPending = false;
+    }
     if (body.additionalSystemPrompt !== undefined) data.additionalSystemPrompt = normalizeAdditionalSystemPrompt(body.additionalSystemPrompt);
     if (body.enabledTools !== undefined) data.enabledTools = body.enabledTools;
 
@@ -932,15 +1110,30 @@ export async function registerRoutes(app: FastifyInstance) {
       select: chatSummarySelect,
     });
     if (!existing) return app.httpErrors.notFound("chat not found");
-    if (existing.title?.trim()) return { chat: serializeChatLike(existing) };
+    if (existing.title?.trim() && !existing.titleGenerationPending) return { chat: serializeChatLike(existing) };
 
     const fallback = body.content.split(/\r?\n/)[0]?.trim().slice(0, 48) || "New chat";
-    const suggestedRaw = await generateChatTitle(body.content);
+    let suggestedRaw = "";
+    try {
+      suggestedRaw = await generateChatTitle(body.content);
+    } catch (err) {
+      req.log.warn(
+        {
+          chatId: body.chatId,
+          err: getErrorMessage(err),
+        },
+        "chat title generation failed; using fallback"
+      );
+    }
     const title = normalizeSuggestedTitle(suggestedRaw, fallback);
 
     await prisma.chat.updateMany({
-      where: { id: body.chatId, title: existing.title },
-      data: { title },
+      where: {
+        id: body.chatId,
+        title: existing.title,
+        titleGenerationPending: existing.titleGenerationPending,
+      },
+      data: { title, titleGenerationPending: false },
     });
 
     const chat = await getChatSummary(body.chatId);
@@ -956,14 +1149,46 @@ export async function registerRoutes(app: FastifyInstance) {
 
     req.log.info({ chatId }, "delete chat requested");
 
-    const result = await prisma.chat.deleteMany({ where: { id: chatId } });
-    if (result.count === 0) {
+    const target = await prisma.chat.findUnique({
+      where: { id: chatId },
+      select: { parentChatId: true },
+    });
+    if (!target) {
       req.log.warn({ chatId }, "delete chat target not found");
       return app.httpErrors.notFound("chat not found");
     }
 
-    req.log.info({ chatId }, "chat deleted");
-    return { deleted: true };
+    const familyRootId = target.parentChatId ?? chatId;
+    if (chatDeletionRoots.has(familyRootId)) {
+      return app.httpErrors.conflict("chat family deletion already in progress");
+    }
+
+    chatDeletionRoots.add(familyRootId);
+    try {
+      const familyIds = target.parentChatId
+        ? [chatId]
+        : (
+            await prisma.chat.findMany({
+              where: { OR: [{ id: chatId }, { parentChatId: chatId }] },
+              select: { id: true },
+            })
+          ).map((chat) => chat.id);
+      if (familyIds.some((id) => activeChatStreams.has(id))) {
+        req.log.warn({ chatId }, "delete chat rejected while chat family is active");
+        return app.httpErrors.conflict("chat or fork has an active stream");
+      }
+
+      const result = await prisma.chat.deleteMany({ where: { id: chatId } });
+      if (result.count === 0) {
+        req.log.warn({ chatId }, "delete chat target no longer exists");
+        return app.httpErrors.notFound("chat not found");
+      }
+
+      req.log.info({ chatId }, "chat deleted");
+      return { deleted: true };
+    } finally {
+      chatDeletionRoots.delete(familyRootId);
+    }
   });
 
   app.get("/v1/searches", async (req) => {
@@ -1253,7 +1478,7 @@ export async function registerRoutes(app: FastifyInstance) {
     const chat = await prisma.chat.findUnique({
       where: { id: chatId },
       include: {
-        messages: { orderBy: { createdAt: "asc" } },
+        messages: { orderBy: [{ createdAt: "asc" }, { id: "asc" }] },
         calls: { orderBy: { createdAt: "desc" } },
         projectItems: starredProjectItemsSelect,
       },
@@ -1347,23 +1572,51 @@ export async function registerRoutes(app: FastifyInstance) {
     if (!parsed.success) return app.httpErrors.badRequest(parsed.error.message);
     const body = withRequestUserLocation(parsed.data, req);
 
-    // ensure chat exists if provided
+    // Ensure the chat exists and identify its family before reserving a stream.
+    let chatFamilyRootId: string | null = null;
     if (body.chatId) {
-      const exists = await prisma.chat.findUnique({ where: { id: body.chatId }, select: { id: true } });
+      const exists = await prisma.chat.findUnique({
+        where: { id: body.chatId },
+        select: { id: true, parentChatId: true },
+      });
       if (!exists) return app.httpErrors.notFound("chat not found");
-    }
-
-    // Store only new non-assistant messages to avoid duplicate history entries.
-    if (body.persist !== false && body.chatId) {
-      await storeNonAssistantMessages(body.chatId, body.messages);
+      chatFamilyRootId = exists.parentChatId ?? exists.id;
     }
 
     if (body.persist !== false && body.chatId) {
-      if (activeChatStreams.has(body.chatId)) {
+      const activeStream = activeChatStreams.get(body.chatId);
+      if (activeStream) {
+        if (body.clientRequestId && activeChatStreamRequestIds.get(body.chatId) === body.clientRequestId) {
+          return streamActiveRun(req, reply, activeStream);
+        }
         return app.httpErrors.conflict("chat completion already running");
       }
-      const stream = startActiveChatStream(body.chatId, await applyStoredChatSettings(body));
-      return streamActiveRun(req, reply, stream);
+
+      if (chatFamilyRootId && chatDeletionRoots.has(chatFamilyRootId)) {
+        return app.httpErrors.conflict("chat family deletion already in progress");
+      }
+
+      const reservedStream = registerActiveChatStream(body.chatId, body.clientRequestId);
+      try {
+        if (body.clientRequestId) {
+          const completedSubmission = await findCompletedChatSubmission(body.chatId, body.clientRequestId);
+          if (completedSubmission) {
+            completeChatSubmissionStream(reservedStream, body.chatId, body, completedSubmission.content);
+            clearActiveChatStream(body.chatId, reservedStream);
+            return streamActiveRun(req, reply, reservedStream);
+          }
+        }
+
+        // Reserve the stream before persistence so deletion cannot interleave with setup.
+        await storeNonAssistantMessages(body.chatId, body.messages, body.clientRequestId);
+        const configuredBody = await applyStoredChatSettings(body);
+        executeActiveChatStream(body.chatId, configuredBody, reservedStream);
+        return streamActiveRun(req, reply, reservedStream);
+      } catch (err) {
+        reservedStream.complete({ event: "error", data: { message: getErrorMessage(err) } });
+        clearActiveChatStream(body.chatId, reservedStream);
+        throw err;
+      }
     }
 
     reply.raw.writeHead(200, buildSseHeaders(typeof req.headers.origin === "string" ? req.headers.origin : undefined));

server/src/search/brave.ts

@@ -0,0 +1,305 @@
+import { buildBrowserLikeRequestHeaders } from "../browser-fetch-headers.js";
+import { env } from "../env.js";
+
+const BRAVE_WEB_SEARCH_URL = "https://api.search.brave.com/res/v1/web/search";
+const BRAVE_SEARCH_TIMEOUT_MS = 12_000;
+const DEFAULT_BRAVE_REQUEST_INTERVAL_MS = 1_000;
+const RATE_LIMIT_INTERVAL_SAFETY_RATIO = 0.05;
+const MIN_RATE_LIMIT_INTERVAL_SAFETY_MS = 2;
+const RATE_LIMIT_RESET_SAFETY_MS = 50;
+const MAX_RATE_LIMIT_RETRIES = 3;
+const MAX_RATE_LIMIT_RETRY_DELAY_MS = 8_000;
+
+type RateLimitPolicy = {
+  limit: number;
+  windowSeconds: number;
+};
+
+let requestIntervalMs = addIntervalSafety(DEFAULT_BRAVE_REQUEST_INTERVAL_MS);
+let lastRequestAtMs = 0;
+let nextRequestAtMs = 0;
+let quotaUnavailableUntilMs = 0;
+let requestQueue = Promise.resolve();
+
+export type BraveSearchOptions = {
+  numResults: number;
+  includeDomains?: string[];
+  excludeDomains?: string[];
+};
+
+export type BraveSearchResult = {
+  title: string | null;
+  url: string | null;
+  publishedDate: string | null;
+  author: string | null;
+  summary: string | null;
+  text: string | null;
+  highlights: string[];
+};
+
+export type BraveSearchResponse = {
+  query: string;
+  requestId: string | null;
+  results: BraveSearchResult[];
+};
+
+function clipText(input: string, maxCharacters: number) {
+  return input.length <= maxCharacters ? input : `${input.slice(0, maxCharacters)}...`;
+}
+
+function compactWhitespace(input: string) {
+  return input.replace(/\r/g, "").replace(/[ \t]+\n/g, "\n").replace(/\n{3,}/g, "\n\n").replace(/\s+/g, " ").trim();
+}
+
+function requireBraveSearchApiKey() {
+  if (!env.BRAVE_SEARCH_API_KEY) {
+    throw new Error("BRAVE_SEARCH_API_KEY not set");
+  }
+  return env.BRAVE_SEARCH_API_KEY;
+}
+
+function sleep(milliseconds: number) {
+  return new Promise<void>((resolve) => setTimeout(resolve, milliseconds));
+}
+
+function addIntervalSafety(intervalMs: number) {
+  return intervalMs + Math.max(MIN_RATE_LIMIT_INTERVAL_SAFETY_MS, Math.ceil(intervalMs * RATE_LIMIT_INTERVAL_SAFETY_RATIO));
+}
+
+function parseCommaSeparatedNumbers(value: string | null) {
+  if (!value) return [];
+  return value.split(",").map((part) => Number(part.trim())).map((number) => (Number.isFinite(number) ? number : null));
+}
+
+function parseRateLimitPolicy(value: string | null): RateLimitPolicy[] {
+  if (!value) return [];
+  return value.split(",").flatMap((part) => {
+    const match = part.trim().match(/^(\d+)\s*;\s*w=(\d+)$/i);
+    if (!match) return [];
+    const limit = Number(match[1]);
+    const windowSeconds = Number(match[2]);
+    return limit > 0 && windowSeconds > 0 ? [{ limit, windowSeconds }] : [];
+  });
+}
+
+function getBurstPolicyIndex(policies: RateLimitPolicy[]) {
+  if (!policies.length) return null;
+  let burstIndex = 0;
+  for (let index = 1; index < policies.length; index += 1) {
+    if (policies[index]!.windowSeconds < policies[burstIndex]!.windowSeconds) burstIndex = index;
+  }
+  return burstIndex;
+}
+
+function updateRateLimitState(headers: Headers) {
+  const policies = parseRateLimitPolicy(headers.get("x-ratelimit-policy"));
+  const burstIndex = getBurstPolicyIndex(policies);
+  if (burstIndex === null) return;
+
+  const burstPolicy = policies[burstIndex]!;
+  const learnedIntervalMs = addIntervalSafety(Math.ceil((burstPolicy.windowSeconds * 1_000) / burstPolicy.limit));
+  if (learnedIntervalMs < requestIntervalMs && lastRequestAtMs > 0) {
+    nextRequestAtMs = Math.min(nextRequestAtMs, lastRequestAtMs + learnedIntervalMs);
+  }
+  requestIntervalMs = learnedIntervalMs;
+
+  const remaining = parseCommaSeparatedNumbers(headers.get("x-ratelimit-remaining"));
+  const resetSeconds = parseCommaSeparatedNumbers(headers.get("x-ratelimit-reset"));
+  for (let index = 0; index < policies.length; index += 1) {
+    if ((remaining[index] ?? null) === null || remaining[index]! >= 1 || (resetSeconds[index] ?? 0) <= 0) continue;
+    const unavailableUntilMs = Date.now() + resetSeconds[index]! * 1_000 + RATE_LIMIT_RESET_SAFETY_MS;
+    if (index === burstIndex) {
+      nextRequestAtMs = Math.max(nextRequestAtMs, unavailableUntilMs);
+    } else {
+      quotaUnavailableUntilMs = Math.max(quotaUnavailableUntilMs, unavailableUntilMs);
+    }
+  }
+}
+
+function assertLongTermQuotaAvailable() {
+  if (quotaUnavailableUntilMs <= Date.now()) {
+    quotaUnavailableUntilMs = 0;
+    return;
+  }
+  const resetSeconds = Math.ceil((quotaUnavailableUntilMs - Date.now()) / 1_000);
+  throw new Error(`Brave Search API long-term quota is exhausted; reset is expected in ${resetSeconds} seconds.`);
+}
+
+async function waitForRateLimitSlot() {
+  const reservation = requestQueue.then(async () => {
+    while (true) {
+      assertLongTermQuotaAvailable();
+      const waitMs = nextRequestAtMs - Date.now();
+      if (waitMs <= 0) break;
+      await sleep(waitMs);
+    }
+    lastRequestAtMs = Date.now();
+    nextRequestAtMs = lastRequestAtMs + requestIntervalMs;
+  });
+  requestQueue = reservation.catch(() => undefined);
+  await reservation;
+}
+
+function get429RetryDelayMs(headers: Headers, retryNumber: number) {
+  const remaining = parseCommaSeparatedNumbers(headers.get("x-ratelimit-remaining"));
+  const resetSeconds = parseCommaSeparatedNumbers(headers.get("x-ratelimit-reset"));
+  const exhaustedResetSeconds = resetSeconds.filter((reset, index): reset is number => reset !== null && (remaining[index] ?? 0) < 1);
+  const headerDelayMs = exhaustedResetSeconds.length ? Math.max(...exhaustedResetSeconds) * 1_000 : 0;
+  const exponentialDelayMs = 2 ** retryNumber * 1_000;
+  const delayMs = Math.max(headerDelayMs + RATE_LIMIT_RESET_SAFETY_MS, exponentialDelayMs);
+  return delayMs <= MAX_RATE_LIMIT_RETRY_DELAY_MS ? delayMs : null;
+}
+
+async function fetchBrave(url: URL) {
+  const apiKey = requireBraveSearchApiKey();
+  for (let attempt = 0; attempt <= MAX_RATE_LIMIT_RETRIES; attempt += 1) {
+    await waitForRateLimitSlot();
+
+    const controller = new AbortController();
+    const timeout = setTimeout(() => controller.abort(), BRAVE_SEARCH_TIMEOUT_MS);
+    let response: Response;
+    try {
+      response = await fetch(url, {
+        signal: controller.signal,
+        headers: {
+          ...buildBrowserLikeRequestHeaders("application/json"),
+          "X-Subscription-Token": apiKey,
+        },
+      });
+    } finally {
+      clearTimeout(timeout);
+    }
+
+    updateRateLimitState(response.headers);
+    if (response.status !== 429 || attempt === MAX_RATE_LIMIT_RETRIES) return response;
+
+    const retryDelayMs = get429RetryDelayMs(response.headers, attempt);
+    await response.arrayBuffer();
+    if (retryDelayMs === null) {
+      throw new Error("Brave Search API rate limit quota is exhausted beyond the retry window.");
+    }
+    await sleep(retryDelayMs);
+  }
+
+  throw new Error("Brave Search API request failed after rate-limit retries.");
+}
+
+function normalizeDomain(input: string) {
+  const trimmed = input.trim().toLowerCase();
+  if (!trimmed) return null;
+
+  try {
+    const parsed = new URL(trimmed.includes("://") ? trimmed : `https://${trimmed}`);
+    return parsed.hostname.replace(/^www\./, "");
+  } catch {
+    return trimmed.split(/[/?#]/, 1)[0]?.replace(/^www\./, "") || null;
+  }
+}
+
+function normalizeDomains(input: string[] | undefined) {
+  return Array.from(new Set((input ?? []).map(normalizeDomain).filter((domain): domain is string => Boolean(domain))));
+}
+
+function hostnameMatchesDomain(urlRaw: string | null, domain: string) {
+  if (!urlRaw) return false;
+  try {
+    const hostname = new URL(urlRaw).hostname.toLowerCase().replace(/^www\./, "");
+    return hostname === domain || hostname.endsWith(`.${domain}`);
+  } catch {
+    return false;
+  }
+}
+
+function filterResultsByDomains(results: BraveSearchResult[], options: BraveSearchOptions) {
+  const includeDomains = normalizeDomains(options.includeDomains);
+  const excludeDomains = normalizeDomains(options.excludeDomains);
+  return results.filter((result) => {
+    if (includeDomains.length && !includeDomains.some((domain) => hostnameMatchesDomain(result.url, domain))) return false;
+    if (excludeDomains.some((domain) => hostnameMatchesDomain(result.url, domain))) return false;
+    return true;
+  });
+}
+
+function buildBraveQuery(query: string, options: BraveSearchOptions) {
+  const includeDomains = normalizeDomains(options.includeDomains);
+  const excludeDomains = normalizeDomains(options.excludeDomains);
+  const includeClause =
+    includeDomains.length === 0
+      ? ""
+      : includeDomains.length === 1
+        ? `site:${includeDomains[0]}`
+        : `(${includeDomains.map((domain) => `site:${domain}`).join(" OR ")})`;
+  const excludeClause = excludeDomains.map((domain) => `-site:${domain}`).join(" ");
+  return [query, includeClause, excludeClause].filter(Boolean).join(" ");
+}
+
+function buildSearchUrl(query: string, options: BraveSearchOptions) {
+  const url = new URL(BRAVE_WEB_SEARCH_URL);
+  url.searchParams.set("q", buildBraveQuery(query, options));
+  url.searchParams.set("count", String(options.numResults));
+  url.searchParams.set("safesearch", "moderate");
+  url.searchParams.set("result_filter", "web");
+  url.searchParams.set("text_decorations", "false");
+  url.searchParams.set("extra_snippets", "true");
+  return url;
+}
+
+function stringOrNull(value: unknown) {
+  if (typeof value !== "string") return null;
+  const normalized = compactWhitespace(value);
+  return normalized || null;
+}
+
+function stringArray(value: unknown) {
+  if (!Array.isArray(value)) return [];
+  return value.filter((item): item is string => typeof item === "string").map(compactWhitespace).filter(Boolean);
+}
+
+function mapWebResult(result: any): BraveSearchResult {
+  const description = stringOrNull(result?.description);
+  const extraSnippets = stringArray(result?.extra_snippets);
+  const snippets = [description, ...extraSnippets].filter((snippet): snippet is string => Boolean(snippet));
+  const combinedText = snippets.join("\n\n");
+
+  return {
+    title: stringOrNull(result?.title),
+    url: stringOrNull(result?.url),
+    publishedDate: stringOrNull(result?.page_age),
+    author: stringOrNull(result?.profile?.name) ?? stringOrNull(result?.article?.author),
+    summary: description ? clipText(description, 1_400) : null,
+    text: combinedText ? clipText(combinedText, 700) : null,
+    highlights: snippets.slice(0, 3).map((snippet) => clipText(snippet, 280)),
+  };
+}
+
+export async function searchBrave(query: string, options: BraveSearchOptions): Promise<BraveSearchResponse> {
+  const url = buildSearchUrl(query, options);
+  const response = await fetchBrave(url);
+
+  if (!response.ok) {
+    await response.arrayBuffer();
+    throw new Error(`Brave Search API request failed with status ${response.status}.`);
+  }
+
+  const contentType = response.headers.get("content-type")?.toLowerCase() ?? "";
+  if (!contentType.includes("application/json")) {
+    await response.arrayBuffer();
+    throw new Error(`Brave Search API returned ${contentType || "unknown content type"}.`);
+  }
+
+  const data: any = await response.json();
+  const results = Array.isArray(data?.web?.results) ? data.web.results.map(mapWebResult) : [];
+  return {
+    query,
+    requestId: response.headers.get("x-request-id"),
+    results: filterResultsByDomains(results, options).slice(0, options.numResults),
+  };
+}
+
+export function resetBraveRateLimitStateForTests() {
+  requestIntervalMs = addIntervalSafety(DEFAULT_BRAVE_REQUEST_INTERVAL_MS);
+  lastRequestAtMs = 0;
+  nextRequestAtMs = 0;
+  quotaUnavailableUntilMs = 0;
+  requestQueue = Promise.resolve();
+}

server/tests/brave-search.test.ts

@@ -0,0 +1,284 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { env } from "../src/env.js";
+import { resetBraveRateLimitStateForTests, searchBrave } from "../src/search/brave.js";
+
+test("searchBrave authenticates, builds filters, and normalizes web results", async () => {
+  const originalFetch = globalThis.fetch;
+  const originalApiKey = env.BRAVE_SEARCH_API_KEY;
+  const fetchCalls: Array<{ input: RequestInfo | URL; init?: RequestInit }> = [];
+  resetBraveRateLimitStateForTests();
+  env.BRAVE_SEARCH_API_KEY = "test-brave-key";
+  globalThis.fetch = (async (input: RequestInfo | URL, init?: RequestInit) => {
+    fetchCalls.push({ input, init });
+    return new Response(
+      JSON.stringify({
+        web: {
+          results: [
+            {
+              title: " Brave result ",
+              url: "https://docs.example.com/article",
+              description: "Main\n snippet",
+              extra_snippets: ["Extra snippet one", "Extra snippet two"],
+              page_age: "2026-07-18T12:00:00Z",
+              profile: { name: "Example Docs" },
+            },
+            {
+              title: "Excluded result",
+              url: "https://blocked.example.com/article",
+              description: "Should be filtered",
+            },
+          ],
+        },
+      }),
+      {
+        status: 200,
+        headers: {
+          "content-type": "application/json; charset=utf-8",
+          "x-request-id": "brave-request-1",
+        },
+      }
+    );
+  }) as typeof fetch;
+
+  try {
+    const response = await searchBrave("latest docs", {
+      numResults: 5,
+      includeDomains: ["https://example.com/path"],
+      excludeDomains: ["blocked.example.com"],
+    });
+
+    assert.equal(fetchCalls.length, 1);
+    const requestUrl = new URL(String(fetchCalls[0]?.input));
+    assert.equal(requestUrl.origin + requestUrl.pathname, "https://api.search.brave.com/res/v1/web/search");
+    assert.equal(requestUrl.searchParams.get("q"), "latest docs site:example.com -site:blocked.example.com");
+    assert.equal(requestUrl.searchParams.get("count"), "5");
+    assert.equal(requestUrl.searchParams.get("safesearch"), "moderate");
+    assert.equal(requestUrl.searchParams.get("result_filter"), "web");
+    assert.equal(requestUrl.searchParams.get("text_decorations"), "false");
+    assert.equal(requestUrl.searchParams.get("extra_snippets"), "true");
+    assert.equal((fetchCalls[0]?.init?.headers as Record<string, string>)["X-Subscription-Token"], "test-brave-key");
+
+    assert.deepEqual(response, {
+      query: "latest docs",
+      requestId: "brave-request-1",
+      results: [
+        {
+          title: "Brave result",
+          url: "https://docs.example.com/article",
+          publishedDate: "2026-07-18T12:00:00Z",
+          author: "Example Docs",
+          summary: "Main snippet",
+          text: "Main snippet\n\nExtra snippet one\n\nExtra snippet two",
+          highlights: ["Main snippet", "Extra snippet one", "Extra snippet two"],
+        },
+      ],
+    });
+  } finally {
+    globalThis.fetch = originalFetch;
+    env.BRAVE_SEARCH_API_KEY = originalApiKey;
+  }
+});
+
+test("searchBrave rejects requests without an API key", async () => {
+  const originalApiKey = env.BRAVE_SEARCH_API_KEY;
+  resetBraveRateLimitStateForTests();
+  env.BRAVE_SEARCH_API_KEY = undefined;
+  try {
+    await assert.rejects(() => searchBrave("test", { numResults: 1 }), /BRAVE_SEARCH_API_KEY not set/);
+  } finally {
+    env.BRAVE_SEARCH_API_KEY = originalApiKey;
+  }
+});
+
+test("searchBrave reports non-JSON responses", async () => {
+  const originalFetch = globalThis.fetch;
+  const originalApiKey = env.BRAVE_SEARCH_API_KEY;
+  resetBraveRateLimitStateForTests();
+  env.BRAVE_SEARCH_API_KEY = "test-brave-key";
+  globalThis.fetch = (async () =>
+    new Response("upstream error", {
+      status: 200,
+      headers: { "content-type": "text/plain" },
+    })) as typeof fetch;
+
+  try {
+    await assert.rejects(
+      () => searchBrave("test", { numResults: 1 }),
+      /Brave Search API returned text\/plain/
+    );
+  } finally {
+    globalThis.fetch = originalFetch;
+    env.BRAVE_SEARCH_API_KEY = originalApiKey;
+  }
+});
+
+test("searchBrave evenly paces concurrent bursts using Brave's shortest policy window", async () => {
+  const originalFetch = globalThis.fetch;
+  const originalApiKey = env.BRAVE_SEARCH_API_KEY;
+  const requestStartedAt: number[] = [];
+  resetBraveRateLimitStateForTests();
+  env.BRAVE_SEARCH_API_KEY = "test-brave-key";
+  globalThis.fetch = (async () => {
+    requestStartedAt.push(Date.now());
+    return new Response(JSON.stringify({ web: { results: [] } }), {
+      status: 200,
+      headers: {
+        "content-type": "application/json",
+        "x-ratelimit-policy": "1;w=1, 2000;w=2678400",
+        "x-ratelimit-remaining": "1, 1999",
+        "x-ratelimit-reset": "1, 2678400",
+      },
+    });
+  }) as typeof fetch;
+
+  try {
+    await Promise.all([
+      searchBrave("burst one", { numResults: 1 }),
+      searchBrave("burst two", { numResults: 1 }),
+      searchBrave("burst three", { numResults: 1 }),
+    ]);
+
+    assert.equal(requestStartedAt.length, 3);
+    assert.ok(requestStartedAt[1]! - requestStartedAt[0]! >= 1_000);
+    assert.ok(requestStartedAt[2]! - requestStartedAt[1]! >= 1_000);
+  } finally {
+    globalThis.fetch = originalFetch;
+    env.BRAVE_SEARCH_API_KEY = originalApiKey;
+    resetBraveRateLimitStateForTests();
+  }
+});
+
+test("searchBrave adapts its pacing to a 50 request-per-second Search plan", async () => {
+  const originalFetch = globalThis.fetch;
+  const originalApiKey = env.BRAVE_SEARCH_API_KEY;
+  const requestStartedAt: number[] = [];
+  resetBraveRateLimitStateForTests();
+  env.BRAVE_SEARCH_API_KEY = "test-brave-key";
+  globalThis.fetch = (async () => {
+    requestStartedAt.push(Date.now());
+    return new Response(JSON.stringify({ web: { results: [] } }), {
+      status: 200,
+      headers: {
+        "content-type": "application/json",
+        "x-ratelimit-policy": "50;w=1, 0;w=2678400",
+        "x-ratelimit-remaining": "49, 0",
+        "x-ratelimit-reset": "1, 2678400",
+      },
+    });
+  }) as typeof fetch;
+
+  try {
+    await searchBrave("learn upgraded policy", { numResults: 1 });
+    await Promise.all(Array.from({ length: 8 }, (_, index) => searchBrave(`fast burst ${index}`, { numResults: 1 })));
+
+    assert.equal(requestStartedAt.length, 9);
+    const burstStartedAt = requestStartedAt.slice(1);
+    for (let index = 1; index < burstStartedAt.length; index += 1) {
+      assert.ok(burstStartedAt[index]! - burstStartedAt[index - 1]! >= 18);
+    }
+    assert.ok(burstStartedAt.at(-1)! - burstStartedAt[0]! < 500);
+  } finally {
+    globalThis.fetch = originalFetch;
+    env.BRAVE_SEARCH_API_KEY = originalApiKey;
+    resetBraveRateLimitStateForTests();
+  }
+});
+
+test("searchBrave retries 429 responses after the burst window resets", async () => {
+  const originalFetch = globalThis.fetch;
+  const originalApiKey = env.BRAVE_SEARCH_API_KEY;
+  let fetchCount = 0;
+  resetBraveRateLimitStateForTests();
+  env.BRAVE_SEARCH_API_KEY = "test-brave-key";
+  globalThis.fetch = (async () => {
+    fetchCount += 1;
+    const rateLimitHeaders = {
+      "content-type": "application/json",
+      "x-ratelimit-policy": "1;w=1, 2000;w=2678400",
+      "x-ratelimit-remaining": fetchCount === 1 ? "0, 1999" : "1, 1998",
+      "x-ratelimit-reset": "1, 2678400",
+    };
+    if (fetchCount === 1) {
+      return new Response(JSON.stringify({ error: { detail: "Rate limit exceeded" } }), {
+        status: 429,
+        headers: rateLimitHeaders,
+      });
+    }
+    return new Response(JSON.stringify({ web: { results: [] } }), { status: 200, headers: rateLimitHeaders });
+  }) as typeof fetch;
+
+  try {
+    const startedAt = Date.now();
+    await searchBrave("retry burst", { numResults: 1 });
+    assert.equal(fetchCount, 2);
+    assert.ok(Date.now() - startedAt >= 1_000);
+  } finally {
+    globalThis.fetch = originalFetch;
+    env.BRAVE_SEARCH_API_KEY = originalApiKey;
+    resetBraveRateLimitStateForTests();
+  }
+});
+
+test("searchBrave does not wait for exhausted long-term quotas", async () => {
+  const originalFetch = globalThis.fetch;
+  const originalApiKey = env.BRAVE_SEARCH_API_KEY;
+  resetBraveRateLimitStateForTests();
+  env.BRAVE_SEARCH_API_KEY = "test-brave-key";
+  globalThis.fetch = (async () =>
+    new Response(JSON.stringify({ error: { detail: "Quota exceeded" } }), {
+      status: 429,
+      headers: {
+        "content-type": "application/json",
+        "x-ratelimit-policy": "1;w=1, 2000;w=2678400",
+        "x-ratelimit-remaining": "0, 0",
+        "x-ratelimit-reset": "1, 100000",
+      },
+    })) as typeof fetch;
+
+  try {
+    const startedAt = Date.now();
+    await assert.rejects(
+      () => searchBrave("quota exhausted", { numResults: 1 }),
+      /rate limit quota is exhausted beyond the retry window/
+    );
+    assert.ok(Date.now() - startedAt < 1_000);
+  } finally {
+    globalThis.fetch = originalFetch;
+    env.BRAVE_SEARCH_API_KEY = originalApiKey;
+    resetBraveRateLimitStateForTests();
+  }
+});
+
+test("searchBrave blocks locally after a successful request exhausts the long-term quota", async () => {
+  const originalFetch = globalThis.fetch;
+  const originalApiKey = env.BRAVE_SEARCH_API_KEY;
+  let fetchCount = 0;
+  resetBraveRateLimitStateForTests();
+  env.BRAVE_SEARCH_API_KEY = "test-brave-key";
+  globalThis.fetch = (async () => {
+    fetchCount += 1;
+    return new Response(JSON.stringify({ web: { results: [] } }), {
+      status: 200,
+      headers: {
+        "content-type": "application/json",
+        "x-ratelimit-policy": "1;w=1, 2000;w=2678400",
+        "x-ratelimit-remaining": "0, 0",
+        "x-ratelimit-reset": "1, 100000",
+      },
+    });
+  }) as typeof fetch;
+
+  try {
+    await searchBrave("last allowed query", { numResults: 1 });
+    await assert.rejects(
+      () => searchBrave("over quota query", { numResults: 1 }),
+      /long-term quota is exhausted/
+    );
+    assert.equal(fetchCount, 1);
+  } finally {
+    globalThis.fetch = originalFetch;
+    env.BRAVE_SEARCH_API_KEY = originalApiKey;
+    resetBraveRateLimitStateForTests();
+  }
+});

server/tests/chat-forks.test.ts

@@ -0,0 +1,252 @@
+import assert from "node:assert/strict";
+import { execFileSync } from "node:child_process";
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { dirname, join, resolve } from "node:path";
+import test from "node:test";
+import { fileURLToPath } from "node:url";
+import Fastify from "fastify";
+import sensible from "@fastify/sensible";
+
+const serverRoot = resolve(dirname(fileURLToPath(import.meta.url)), "..");
+const databaseDir = mkdtempSync(join(tmpdir(), "sybil-chat-forks-"));
+process.env.DATABASE_URL = `file:${join(databaseDir, "test.db")}`;
+process.env.OPENAI_API_KEY = "";
+delete process.env.ADMIN_TOKEN;
+
+execFileSync(process.execPath, [join(serverRoot, "node_modules/prisma/build/index.js"), "migrate", "deploy"], {
+  cwd: serverRoot,
+  env: { ...process.env, PRISMA_HIDE_UPDATE_MESSAGE: "1" },
+  stdio: "pipe",
+});
+
+const [{ clearActiveChatStream, registerActiveChatStream, registerRoutes }, { prisma }] = await Promise.all([
+  import("../src/routes.js"),
+  import("../src/db.js"),
+]);
+const app = Fastify({ logger: false });
+await app.register(sensible);
+await registerRoutes(app);
+await app.ready();
+
+test.after(async () => {
+  await app.close();
+  await prisma.$disconnect();
+  rmSync(databaseDir, { recursive: true, force: true });
+});
+
+test("forks copy bounded history and keep every child grouped under the root", async () => {
+  const timestamp = new Date("2026-08-16T12:00:00.000Z");
+  const source = await prisma.chat.create({
+    data: {
+      title: "Planning session",
+      initiatedProvider: "openai",
+      initiatedModel: "gpt-4.1-mini",
+      lastUsedProvider: "anthropic",
+      lastUsedModel: "claude-sonnet-4-20250514",
+      additionalSystemPrompt: "Keep answers concise.",
+      enabledTools: ["web_search"],
+      messages: {
+        create: [
+          {
+            id: "source-message-0001",
+            createdAt: timestamp,
+            role: "user",
+            content: "Plan a trip",
+            metadata: {
+              clientRequestId: "source-request",
+              attachments: [{ kind: "text", filename: "notes.txt" }],
+            },
+          },
+          {
+            id: "source-message-0002",
+            createdAt: timestamp,
+            role: "assistant",
+            content: "First assistant response",
+            metadata: { clientRequestId: "source-request", citations: ["https://example.com"] },
+          },
+          {
+            id: "source-message-0003",
+            createdAt: timestamp,
+            role: "user",
+            content: "Only visible in a whole-chat fork",
+          },
+        ],
+      },
+      calls: {
+        create: {
+          provider: "openai",
+          model: "gpt-4.1-mini",
+          request: { input: "Plan a trip" },
+        },
+      },
+    },
+    include: { messages: { orderBy: [{ createdAt: "asc" }, { id: "asc" }] } },
+  });
+
+  const forkResponse = await app.inject({
+    method: "POST",
+    url: `/v1/chats/${source.id}/fork`,
+    payload: { messageId: source.messages[1].id },
+  });
+  assert.equal(forkResponse.statusCode, 200, forkResponse.body);
+  const forkSummary = forkResponse.json().chat;
+  assert.equal(forkSummary.parentChatId, source.id);
+  assert.equal(forkSummary.title, "Fork of 'First assistant response'");
+  assert.equal(forkSummary.titleGenerationPending, true);
+  assert.equal(forkSummary.starred, false);
+
+  const detailResponse = await app.inject({ method: "GET", url: `/v1/chats/${forkSummary.id}` });
+  assert.equal(detailResponse.statusCode, 200, detailResponse.body);
+  const fork = detailResponse.json().chat;
+  assert.deepEqual(
+    fork.messages.map((message: any) => [message.role, message.content]),
+    [
+      ["user", "Plan a trip"],
+      ["assistant", "First assistant response"],
+    ]
+  );
+  assert.notEqual(fork.messages[0].id, source.messages[0].id);
+  assert.equal(fork.messages[0].createdAt, timestamp.toISOString());
+  assert.deepEqual(fork.messages[0].metadata, {
+    attachments: [{ kind: "text", filename: "notes.txt" }],
+  });
+  assert.deepEqual(fork.messages[1].metadata, { citations: ["https://example.com"] });
+  assert.equal(fork.initiatedProvider, "openai");
+  assert.equal(fork.initiatedModel, "gpt-4.1-mini");
+  assert.equal(fork.lastUsedProvider, "anthropic");
+  assert.equal(fork.lastUsedModel, "claude-sonnet-4-20250514");
+  assert.equal(fork.additionalSystemPrompt, "Keep answers concise.");
+  assert.deepEqual(fork.enabledTools, ["web_search"]);
+  assert.deepEqual(fork.calls, []);
+
+  const childForkResponse = await app.inject({
+    method: "POST",
+    url: `/v1/chats/${forkSummary.id}/fork`,
+    payload: {},
+  });
+  assert.equal(childForkResponse.statusCode, 200, childForkResponse.body);
+  const childFork = childForkResponse.json().chat;
+  assert.equal(childFork.parentChatId, source.id);
+  assert.equal(childFork.title, "Fork of Fork of 'First assistant response'");
+  assert.equal(childFork.titleGenerationPending, true);
+
+  const wholeForkResponse = await app.inject({
+    method: "POST",
+    url: `/v1/chats/${source.id}/fork`,
+    payload: {},
+  });
+  assert.equal(wholeForkResponse.statusCode, 200, wholeForkResponse.body);
+  const wholeFork = wholeForkResponse.json().chat;
+  assert.equal(wholeFork.parentChatId, source.id);
+  assert.equal(wholeFork.title, "Fork of Planning session");
+  const wholeForkDetail = await app.inject({ method: "GET", url: `/v1/chats/${wholeFork.id}` });
+  assert.equal(wholeForkDetail.statusCode, 200, wholeForkDetail.body);
+  assert.deepEqual(
+    wholeForkDetail.json().chat.messages.map((message: any) => message.content),
+    ["Plan a trip", "First assistant response", "Only visible in a whole-chat fork"]
+  );
+  assert.equal(wholeForkDetail.json().chat.messages[2].metadata, null);
+
+  const suggestedTitleResponse = await app.inject({
+    method: "POST",
+    url: "/v1/chats/title/suggest",
+    payload: { chatId: wholeFork.id, content: "Compare rail and air options" },
+  });
+  assert.equal(suggestedTitleResponse.statusCode, 200, suggestedTitleResponse.body);
+  assert.equal(suggestedTitleResponse.json().chat.title, "Compare rail and air");
+  assert.equal(suggestedTitleResponse.json().chat.titleGenerationPending, false);
+
+  const repeatedTitleResponse = await app.inject({
+    method: "POST",
+    url: "/v1/chats/title/suggest",
+    payload: { chatId: wholeFork.id, content: "This must not overwrite the generated title" },
+  });
+  assert.equal(repeatedTitleResponse.statusCode, 200, repeatedTitleResponse.body);
+  assert.equal(repeatedTitleResponse.json().chat.title, "Compare rail and air");
+
+  const sourceAfterForks = await prisma.chat.findUniqueOrThrow({
+    where: { id: source.id },
+    include: { messages: true, calls: true },
+  });
+  assert.equal(sourceAfterForks.messages.length, 3);
+  assert.equal(sourceAfterForks.calls.length, 1);
+
+  const manualTitleResponse = await app.inject({
+    method: "PATCH",
+    url: `/v1/chats/${forkSummary.id}`,
+    payload: { title: "Manual branch title" },
+  });
+  assert.equal(manualTitleResponse.statusCode, 200, manualTitleResponse.body);
+  assert.equal(manualTitleResponse.json().chat.titleGenerationPending, false);
+
+  const activeForkStream = registerActiveChatStream(wholeFork.id);
+  try {
+    const deleteActiveRootResponse = await app.inject({ method: "DELETE", url: `/v1/chats/${source.id}` });
+    assert.equal(deleteActiveRootResponse.statusCode, 409, deleteActiveRootResponse.body);
+    assert.equal(deleteActiveRootResponse.json().message, "chat or fork has an active stream");
+
+    const deleteActiveForkResponse = await app.inject({ method: "DELETE", url: `/v1/chats/${wholeFork.id}` });
+    assert.equal(deleteActiveForkResponse.statusCode, 409, deleteActiveForkResponse.body);
+  } finally {
+    clearActiveChatStream(wholeFork.id, activeForkStream);
+  }
+
+  const deleteChildResponse = await app.inject({ method: "DELETE", url: `/v1/chats/${childFork.id}` });
+  assert.equal(deleteChildResponse.statusCode, 200, deleteChildResponse.body);
+  assert.equal(await prisma.chat.count({ where: { id: { in: [source.id, forkSummary.id, wholeFork.id] } } }), 3);
+
+  const unrelated = await prisma.chat.create({
+    data: {
+      messages: { create: { role: "assistant", content: "Unrelated response" } },
+    },
+    include: { messages: true },
+  });
+  const countBeforeInvalidForks = await prisma.chat.count();
+
+  const wrongChatResponse = await app.inject({
+    method: "POST",
+    url: `/v1/chats/${source.id}/fork`,
+    payload: { messageId: unrelated.messages[0].id },
+  });
+  assert.equal(wrongChatResponse.statusCode, 404, wrongChatResponse.body);
+  assert.equal(wrongChatResponse.json().message, "message not found in chat");
+
+  const nonAssistantResponse = await app.inject({
+    method: "POST",
+    url: `/v1/chats/${source.id}/fork`,
+    payload: { messageId: source.messages[0].id },
+  });
+  assert.equal(nonAssistantResponse.statusCode, 400, nonAssistantResponse.body);
+  assert.equal(nonAssistantResponse.json().message, "fork message must be an assistant response");
+  assert.equal(await prisma.chat.count(), countBeforeInvalidForks);
+
+  const concurrentTarget = await prisma.chat.create({ data: { title: "Concurrent delete" } });
+  const concurrentDeleteResponses = await Promise.all([
+    app.inject({ method: "DELETE", url: `/v1/chats/${concurrentTarget.id}` }),
+    app.inject({ method: "DELETE", url: `/v1/chats/${concurrentTarget.id}` }),
+  ]);
+  assert.equal(concurrentDeleteResponses.filter((response) => response.statusCode === 200).length, 1);
+  assert.equal(concurrentDeleteResponses.some((response) => response.statusCode >= 500), false);
+
+  const concurrentRoot = await prisma.chat.create({ data: { title: "Concurrent family delete" } });
+  const concurrentChildResponse = await app.inject({
+    method: "POST",
+    url: `/v1/chats/${concurrentRoot.id}/fork`,
+    payload: {},
+  });
+  assert.equal(concurrentChildResponse.statusCode, 200, concurrentChildResponse.body);
+  const concurrentChild = concurrentChildResponse.json().chat;
+  const concurrentFamilyDeleteResponses = await Promise.all([
+    app.inject({ method: "DELETE", url: `/v1/chats/${concurrentRoot.id}` }),
+    app.inject({ method: "DELETE", url: `/v1/chats/${concurrentChild.id}` }),
+  ]);
+  assert.equal(concurrentFamilyDeleteResponses.some((response) => response.statusCode >= 500), false);
+  assert.equal(concurrentFamilyDeleteResponses.some((response) => response.statusCode === 200), true);
+  await prisma.chat.deleteMany({ where: { id: concurrentRoot.id } });
+
+  const deleteRootResponse = await app.inject({ method: "DELETE", url: `/v1/chats/${source.id}` });
+  assert.equal(deleteRootResponse.statusCode, 200, deleteRootResponse.body);
+  assert.equal(await prisma.chat.count({ where: { id: { in: [source.id, forkSummary.id, childFork.id, wholeFork.id] } } }), 0);
+  assert.equal(await prisma.chat.count({ where: { id: unrelated.id } }), 1);
+});

server/tests/provider-adapters.test.ts

@@ -27,6 +27,12 @@ test("provider backend registry selects chat protocol and managed-tool mode", ()
     managedTools: true,
     enabledTools: ["web_search"],
   });
+  assert.deepEqual(describeProviderChatBackend("gemini", ["web_search"]), {
+    provider: "gemini",
+    protocol: "gemini",
+    managedTools: true,
+    enabledTools: ["web_search"],
+  });
   assert.deepEqual(describeProviderChatBackend("hermes-agent", ["web_search"]), {
     provider: "hermes-agent",
     protocol: "chat-completions",

server/tests/provider-ids.test.ts

@@ -5,8 +5,10 @@ import { fromPrismaProvider, serializeProviderFields, toPrismaProvider } from ".
 test("Hermes Agent provider id maps between API and Prisma enum forms", () => {
   assert.equal(toPrismaProvider("hermes-agent"), "hermes_agent");
   assert.equal(fromPrismaProvider("hermes_agent"), "hermes-agent");
-  assert.deepEqual(serializeProviderFields({ initiatedProvider: "hermes_agent", lastUsedProvider: "xai" }), {
+  assert.equal(toPrismaProvider("gemini"), "gemini");
+  assert.equal(fromPrismaProvider("gemini"), "gemini");
+  assert.deepEqual(serializeProviderFields({ initiatedProvider: "hermes_agent", lastUsedProvider: "gemini" }), {
     initiatedProvider: "hermes-agent",
-    lastUsedProvider: "xai",
+    lastUsedProvider: "gemini",
   });
 });

tui/src/config.ts

@@ -1,6 +1,6 @@
 import type { Provider } from "./types.js";
 
-const PROVIDERS: Provider[] = ["openai", "anthropic", "xai", "hermes-agent"];
+const PROVIDERS: Provider[] = ["openai", "anthropic", "xai", "gemini", "hermes-agent"];
 
 function normalizeBaseUrl(value: string) {
   const trimmed = value.trim();

tui/src/index.ts

@@ -42,12 +42,13 @@ type ToolLogMetadata = {
   resultPreview?: string | null;
 };
 
-const BASE_PROVIDERS: Provider[] = ["openai", "anthropic", "xai"];
+const BASE_PROVIDERS: Provider[] = ["openai", "anthropic", "xai", "gemini"];
 const PROVIDERS: Provider[] = [...BASE_PROVIDERS, "hermes-agent"];
 const PROVIDER_FALLBACK_MODELS: Record<Provider, string[]> = {
   openai: ["gpt-4.1-mini"],
   anthropic: ["claude-3-5-sonnet-latest"],
   xai: ["grok-3-mini"],
+  gemini: ["gemini-3.5-flash", "gemini-flash-latest"],
   "hermes-agent": ["hermes-agent"],
 };
 
@@ -55,6 +56,7 @@ const EMPTY_MODEL_CATALOG: ModelCatalogResponse["providers"] = {
   openai: { models: [], loadedAt: null, error: null },
   anthropic: { models: [], loadedAt: null, error: null },
   xai: { models: [], loadedAt: null, error: null },
+  gemini: { models: [], loadedAt: null, error: null },
 };
 
 function escapeTags(value: string) {
@@ -79,6 +81,7 @@ function getProviderLabel(provider: Provider | null | undefined) {
   if (provider === "openai") return "OpenAI";
   if (provider === "anthropic") return "Anthropic";
   if (provider === "xai") return "xAI";
+  if (provider === "gemini") return "Gemini";
   if (provider === "hermes-agent") return "Hermes Agent";
   return "";
 }
@@ -124,21 +127,27 @@ function upsertWorkspaceItem(items: WorkspaceItem[], item: WorkspaceItem) {
 }
 
 function buildSidebarItems(items: WorkspaceItem[]): SidebarItem[] {
+  const chatsById = new Map<string, ChatSummary>();
+  for (const item of items) {
+    if (item.type === "chat") chatsById.set(item.id, item);
+  }
+
   return items.map((item) => {
     if (item.type === "chat") {
       const chat = item;
+      const starOwner = chatsById.get(chat.parentChatId ?? chat.id) ?? chat;
       return {
-      kind: "chat" as const,
-      id: chat.id,
-      title: getChatTitle(chat),
-      updatedAt: chat.updatedAt,
-      createdAt: chat.createdAt,
-      starred: chat.starred,
-      starredAt: chat.starredAt,
-      initiatedProvider: chat.initiatedProvider,
-      initiatedModel: chat.initiatedModel,
-      lastUsedProvider: chat.lastUsedProvider,
-      lastUsedModel: chat.lastUsedModel,
+        kind: "chat" as const,
+        id: chat.id,
+        title: getChatTitle(chat),
+        updatedAt: chat.updatedAt,
+        createdAt: chat.createdAt,
+        starred: starOwner.starred,
+        starredAt: starOwner.starredAt,
+        initiatedProvider: chat.initiatedProvider,
+        initiatedModel: chat.initiatedModel,
+        lastUsedProvider: chat.lastUsedProvider,
+        lastUsedModel: chat.lastUsedModel,
       };
     }
 
@@ -266,6 +275,7 @@ async function main() {
     openai: null,
     anthropic: null,
     xai: null,
+    gemini: null,
     "hermes-agent": null,
   };
   let model: string = config.defaultModel ?? pickProviderModel(getModelOptions(modelCatalog, provider), null);
@@ -975,11 +985,11 @@ async function main() {
     focusComposer();
   }
 
-  async function maybeSuggestTitle(chatId: string, content: string) {
-    const chatSummary = chats.find((chat) => chat.id === chatId);
-    const hasExistingTitle = Boolean(selectedChat?.id === chatId ? selectedChat.title?.trim() : chatSummary?.title?.trim());
-    if (hasExistingTitle || pendingTitleGeneration.has(chatId)) return;
+  async function maybeSuggestTitle(chat: ChatDetail, content: string) {
+    const needsGeneratedTitle = chat.titleGenerationPending || !chat.title?.trim();
+    if (!needsGeneratedTitle || pendingTitleGeneration.has(chat.id)) return;
 
+    const chatId = chat.id;
     pendingTitleGeneration.add(chatId);
     try {
       const updated = await api.suggestChatTitle({ chatId, content });
@@ -989,6 +999,8 @@ async function main() {
         selectedChat = {
           ...selectedChat,
           title: updated.title,
+          parentChatId: updated.parentChatId,
+          titleGenerationPending: updated.titleGenerationPending,
           updatedAt: updated.updatedAt,
           starred: updated.starred,
           starredAt: updated.starredAt,
@@ -1045,6 +1057,8 @@ async function main() {
       selectedChat = {
         id: chat.id,
         title: chat.title,
+        parentChatId: chat.parentChatId,
+        titleGenerationPending: chat.titleGenerationPending,
         createdAt: chat.createdAt,
         updatedAt: chat.updatedAt,
         starred: chat.starred,
@@ -1064,13 +1078,13 @@ async function main() {
       throw new Error("Unable to initialize chat");
     }
 
-    void maybeSuggestTitle(chatId, content);
-
     let baseChat = selectedChat;
     if (!baseChat || baseChat.id !== chatId) {
       baseChat = await api.getChat(chatId);
     }
 
+    void maybeSuggestTitle(baseChat, content);
+
     const requestMessages: CompletionRequestMessage[] = [
       ...baseChat.messages
         .filter((message) => !isToolCallLogMessage(message))
@@ -1388,6 +1402,8 @@ async function main() {
       selectedChat = {
         ...selectedChat,
         title: updated.title,
+        parentChatId: updated.parentChatId,
+        titleGenerationPending: updated.titleGenerationPending,
         updatedAt: updated.updatedAt,
         initiatedProvider: updated.initiatedProvider,
         initiatedModel: updated.initiatedModel,
@@ -1401,12 +1417,16 @@ async function main() {
   async function handleToggleStarSelection() {
     if (!selectedItem) return;
 
-    const currentItem = getSidebarItems().find((item) => item.kind === selectedItem?.kind && item.id === selectedItem?.id);
-    const nextStarred = !currentItem?.starred;
     setError(null);
 
     if (selectedItem.kind === "chat") {
-      const updated = await api.updateChatStar(selectedItem.id, nextStarred);
+      const selectedSummary = chats.find((chat) => chat.id === selectedItem?.id);
+      const selectedParentChatId = selectedChat?.id === selectedItem.id
+        ? selectedChat.parentChatId
+        : selectedSummary?.parentChatId;
+      const rootChatId = selectedParentChatId ?? selectedItem.id;
+      const rootSummary = chats.find((chat) => chat.id === rootChatId);
+      const updated = await api.updateChatStar(rootChatId, !rootSummary?.starred);
       chats = chats.map((chat) => (chat.id === updated.id ? updated : chat));
       if (!chats.some((chat) => chat.id === updated.id)) chats = [updated, ...chats];
       workspaceItems = workspaceItems.map((item) => (item.type === "chat" && item.id === updated.id ? chatWorkspaceItem(updated) : item));
@@ -1417,6 +1437,8 @@ async function main() {
         selectedChat = {
           ...selectedChat,
           title: updated.title,
+          parentChatId: updated.parentChatId,
+          titleGenerationPending: updated.titleGenerationPending,
           updatedAt: updated.updatedAt,
           starred: updated.starred,
           starredAt: updated.starredAt,
@@ -1427,7 +1449,8 @@ async function main() {
         };
       }
     } else {
-      const updated = await api.updateSearchStar(selectedItem.id, nextStarred);
+      const currentItem = getSidebarItems().find((item) => item.kind === "search" && item.id === selectedItem?.id);
+      const updated = await api.updateSearchStar(selectedItem.id, !currentItem?.starred);
       searches = searches.map((search) => (search.id === updated.id ? updated : search));
       if (!searches.some((search) => search.id === updated.id)) searches = [updated, ...searches];
       workspaceItems = workspaceItems.map((item) => (item.type === "search" && item.id === updated.id ? searchWorkspaceItem(updated) : item));

tui/src/types.ts

@@ -1,4 +1,4 @@
-export type Provider = "openai" | "anthropic" | "xai" | "hermes-agent";
+export type Provider = "openai" | "anthropic" | "xai" | "gemini" | "hermes-agent";
 
 export type ProviderModelInfo = {
   models: string[];
@@ -13,6 +13,8 @@ export type ModelCatalogResponse = {
 export type ChatSummary = {
   id: string;
   title: string | null;
+  parentChatId: string | null;
+  titleGenerationPending: boolean;
   createdAt: string;
   updatedAt: string;
   starred: boolean;
@@ -68,6 +70,8 @@ export type ToolCallEvent = {
 export type ChatDetail = {
   id: string;
   title: string | null;
+  parentChatId: string | null;
+  titleGenerationPending: boolean;
   createdAt: string;
   updatedAt: string;
   starred: boolean;

web/package.json

@@ -7,6 +7,7 @@
     "dev": "vite",
     "build": "tsc -b && vite build",
     "preview": "vite preview",
+    "test": "node --test --experimental-strip-types tests/*.test.mjs",
     "typecheck": "tsc --noEmit"
   },
   "dependencies": {

web/public/sw.js

@@ -3,10 +3,24 @@ self.addEventListener("install", () => {
 });
 
 self.addEventListener("activate", (event) => {
-  event.waitUntil(self.clients.claim());
+  event.waitUntil(
+    (async () => {
+      await self.clients.claim();
+      const windows = await self.clients.matchAll({ type: "window", includeUncontrolled: true });
+      await Promise.all(
+        windows.map(async (client) => {
+          try {
+            await client.navigate(client.url);
+          } catch {
+            // The client may have closed while the new worker was activating.
+          }
+        })
+      );
+    })()
+  );
 });
 
 self.addEventListener("fetch", (event) => {
   if (event.request.mode !== "navigate") return;
-  event.respondWith(fetch(event.request));
+  event.respondWith(fetch(new Request(event.request, { cache: "no-store" })));
 });

web/src/components/chat/chat-composer.tsx

@@ -0,0 +1,140 @@
+import { useLayoutEffect, useRef, useState } from "preact/hooks";
+import { Paperclip, Search, SendHorizontal } from "lucide-preact";
+import { Button } from "@/components/ui/button";
+import { Textarea } from "@/components/ui/textarea";
+import { cn } from "@/lib/utils";
+
+type MutableValueRef = {
+  current: string;
+};
+
+type Props = {
+  draftRef: MutableValueRef;
+  draftRevision: number;
+  error: string | null;
+  isSearchMode: boolean;
+  isSending: boolean;
+  pendingAttachmentCount: number;
+  attachmentButtonDisabled: boolean;
+  onOpenAttachmentPicker: () => void;
+  onPaste: (event: ClipboardEvent) => void;
+  onSend: (draft: string) => void | Promise<void>;
+};
+
+const MIRROR_SENTINEL = "\u200b";
+const HAS_NON_WHITESPACE = /\S/;
+
+export function ChatComposer({
+  draftRef,
+  draftRevision,
+  error,
+  isSearchMode,
+  isSending,
+  pendingAttachmentCount,
+  attachmentButtonDisabled,
+  onOpenAttachmentPicker,
+  onPaste,
+  onSend,
+}: Props) {
+  // The draft stays in the DOM/ref so typing never schedules a render of the workspace transcript.
+  const textareaContainerRef = useRef<HTMLDivElement>(null);
+  const mirrorRef = useRef<HTMLDivElement>(null);
+  const [hasDraft, setHasDraft] = useState(() => HAS_NON_WHITESPACE.test(draftRef.current));
+  const hasDraftRef = useRef(hasDraft);
+
+  const getTextarea = () => textareaContainerRef.current?.querySelector("textarea") ?? null;
+
+  const updateMirror = (value: string) => {
+    // The overlapping mirror lets normal layout size the textarea without synchronous scrollHeight reads.
+    if (mirrorRef.current) mirrorRef.current.textContent = `${value}${MIRROR_SENTINEL}`;
+  };
+
+  const updateHasDraft = (value: string) => {
+    const nextHasDraft = HAS_NON_WHITESPACE.test(value);
+    if (nextHasDraft !== hasDraftRef.current) {
+      hasDraftRef.current = nextHasDraft;
+      setHasDraft(nextHasDraft);
+    }
+  };
+
+  useLayoutEffect(() => {
+    const value = draftRef.current;
+    const textarea = getTextarea();
+    if (textarea && textarea.value !== value) {
+      textarea.value = value;
+    }
+    updateMirror(value);
+    updateHasDraft(value);
+  }, [draftRevision]);
+
+  const submit = () => {
+    const textarea = getTextarea();
+    const draft = textarea?.value ?? draftRef.current;
+    const canSend = HAS_NON_WHITESPACE.test(draft) || (!isSearchMode && pendingAttachmentCount > 0);
+    if (isSending || !canSend) return;
+
+    draftRef.current = "";
+    if (textarea) textarea.value = "";
+    updateMirror("");
+    updateHasDraft("");
+    void onSend(draft);
+  };
+
+  return (
+    <>
+      <div ref={textareaContainerRef} className="grid max-h-40 min-h-0 overflow-hidden">
+        <div
+          ref={mirrorRef}
+          className="pointer-events-none invisible col-start-1 row-start-1 max-h-40 min-h-0 overflow-x-hidden overflow-y-auto whitespace-pre-wrap break-words px-3 py-3 text-base"
+          aria-hidden="true"
+        />
+        <Textarea
+          id="composer-input"
+          rows={1}
+          onInput={(event) => {
+            const value = event.currentTarget.value;
+            draftRef.current = value;
+            updateMirror(value);
+            updateHasDraft(value);
+          }}
+          onPaste={(event) => {
+            onPaste(event);
+          }}
+          onKeyDown={(event) => {
+            if (event.key === "Enter" && !event.shiftKey && !event.isComposing) {
+              event.preventDefault();
+              submit();
+            }
+          }}
+          placeholder={isSearchMode ? "Search the web" : "Enter prompt..."}
+          className="col-start-1 row-start-1 h-full max-h-40 min-h-0 resize-none overflow-y-auto border-0 bg-transparent px-3 py-3 text-base text-violet-50 shadow-none placeholder:text-violet-200/45 focus-visible:ring-0"
+          disabled={isSending}
+        />
+      </div>
+      <div className={cn("flex items-center gap-3 px-2 pb-1", error ? "justify-between" : "justify-end")}>
+        {error ? <p className="min-w-0 truncate text-xs text-rose-300">{error}</p> : null}
+        {!isSearchMode ? (
+          <Button
+            className="h-10 w-10 rounded-lg"
+            onClick={onOpenAttachmentPicker}
+            size="icon"
+            variant="secondary"
+            disabled={attachmentButtonDisabled}
+            aria-label="Attach files"
+          >
+            <Paperclip className="h-4 w-4" />
+          </Button>
+        ) : null}
+        <Button
+          className="h-10 w-10 rounded-lg"
+          onClick={submit}
+          size="icon"
+          disabled={isSending || (!hasDraft && (isSearchMode || pendingAttachmentCount === 0))}
+          aria-label={isSearchMode ? "Search" : "Send message"}
+        >
+          {isSearchMode ? <Search className="h-4 w-4" /> : <SendHorizontal className="h-4 w-4" />}
+        </Button>
+      </div>
+    </>
+  );
+}

web/src/components/chat/chat-messages-panel.tsx

@@ -10,6 +10,7 @@ type Props = {
   messages: Message[];
   isLoading: boolean;
   isSending: boolean;
+  onMessageContextMenu?: (event: MouseEvent, messageId: string) => void;
 };
 
 type ToolLogMetadata = {
@@ -395,7 +396,7 @@ function ToolCallStack({
   );
 }
 
-export function ChatMessagesPanel({ messages, isLoading, isSending }: Props) {
+export function ChatMessagesPanel({ messages, isLoading, isSending, onMessageContextMenu }: Props) {
   const hasPendingAssistant = messages.some((message) => message.id.startsWith("temp-assistant-") && message.content.trim().length === 0);
   const renderItems = useMemo(() => buildMessageRenderItems(messages), [messages]);
   const toolCallMessageIDs = useMemo(() => getToolCallMessageIDs(messages), [messages]);
@@ -467,6 +468,11 @@ export function ChatMessagesPanel({ messages, isLoading, isSending }: Props) {
                     ? "rounded-xl border border-violet-300/24 bg-[linear-gradient(135deg,hsl(258_86%_48%_/_0.86),hsl(278_72%_29%_/_0.86))] px-4 py-3 text-sm leading-6 text-fuchsia-50 shadow-sm"
                     : "text-base leading-7 text-violet-50"
                 )}
+                onContextMenu={
+                  message.role === "assistant" && !message.id.startsWith("temp-") && onMessageContextMenu
+                    ? (event) => onMessageContextMenu(event, message.id)
+                    : undefined
+                }
               >
                 {attachments.length ? <ChatAttachmentList attachments={attachments} tone={isUser ? "user" : "assistant"} /> : null}
                 {isPendingAssistant ? (
@@ -478,6 +484,7 @@ export function ChatMessagesPanel({ messages, isLoading, isSending }: Props) {
                 ) : message.content.trim() ? (
                   <MarkdownContent
                     markdown={message.content}
+                    openLinksInNewTab
                     className={cn("[&_a]:text-inherit [&_a]:underline", isUser ? "leading-[1.78] text-fuchsia-50" : "leading-[1.82] text-violet-50")}
                   />
                 ) : null}

web/src/components/markdown/markdown-content.tsx

@@ -10,6 +10,7 @@ type Props = {
   className?: string;
   mode?: MarkdownMode;
   resolveCitationIndex?: (href: string) => number | undefined;
+  openLinksInNewTab?: boolean;
 };
 
 function replaceMarkdownLinksWithCitationTokens(markdown: string, resolveCitationIndex?: (href: string) => number | undefined) {
@@ -28,17 +29,30 @@ markdownRenderer.table = (token) => {
   return `<div class="md-table-scroll">${renderTable(token)}</div>`;
 };
 
-function renderMarkdown(markdown: string) {
-  const rawHtml = marked.parse(markdown, { gfm: true, breaks: true, renderer: markdownRenderer }) as string;
-  return DOMPurify.sanitize(rawHtml, { ADD_ATTR: ["class", "target", "rel"] });
+function setNewTabLinkAttributes(currentNode: Element) {
+  if (currentNode.tagName !== "A") return;
+  currentNode.setAttribute("target", "_blank");
+  currentNode.setAttribute("rel", "noopener noreferrer");
 }
 
-export function MarkdownContent({ markdown, className, mode = "default", resolveCitationIndex }: Props) {
+function renderMarkdown(markdown: string, openLinksInNewTab: boolean) {
+  const rawHtml = marked.parse(markdown, { gfm: true, breaks: true, renderer: markdownRenderer }) as string;
+  if (!openLinksInNewTab) return DOMPurify.sanitize(rawHtml, { ADD_ATTR: ["class", "target", "rel"] });
+
+  DOMPurify.addHook("afterSanitizeAttributes", setNewTabLinkAttributes);
+  try {
+    return DOMPurify.sanitize(rawHtml, { ADD_ATTR: ["class", "target", "rel"] });
+  } finally {
+    DOMPurify.removeHook("afterSanitizeAttributes", setNewTabLinkAttributes);
+  }
+}
+
+export function MarkdownContent({ markdown, className, mode = "default", resolveCitationIndex, openLinksInNewTab = false }: Props) {
   const html = useMemo(() => {
     const prepared =
       mode === "citationTokens" ? replaceMarkdownLinksWithCitationTokens(markdown, resolveCitationIndex) : markdown;
-    return renderMarkdown(prepared);
-  }, [markdown, mode, resolveCitationIndex]);
+    return renderMarkdown(prepared, openLinksInNewTab);
+  }, [markdown, mode, openLinksInNewTab, resolveCitationIndex]);
 
   return <div className={cn("md-content", className)} dangerouslySetInnerHTML={{ __html: html }} />;
 }

web/src/index.css

@@ -131,6 +131,45 @@ textarea {
   }
 }
 
+@media (horizontal-viewport-segments: 2) {
+  .app-safe-frame {
+    padding:
+      max(0.5rem, var(--safe-area-top))
+      max(0.5rem, var(--safe-area-right))
+      max(0.5rem, var(--safe-area-bottom))
+      max(0.5rem, var(--safe-area-left));
+  }
+
+  .workspace-shell {
+    display: grid;
+    grid-template-columns:
+      calc(env(viewport-segment-width 0 0) - max(0.5rem, var(--safe-area-left)))
+      calc(env(viewport-segment-width 1 0) - max(0.5rem, var(--safe-area-right)));
+    column-gap: calc(env(viewport-segment-left 1 0) - env(viewport-segment-right 0 0));
+  }
+
+  .workspace-sidebar {
+    position: static;
+    width: 100%;
+    max-width: none;
+    transform: none;
+    border-width: 1px;
+    border-radius: 1rem;
+  }
+
+  .workspace-content {
+    min-width: 0;
+    border-width: 1px;
+    border-radius: 1rem;
+    touch-action: auto;
+  }
+
+  .workspace-sidebar-backdrop,
+  .workspace-sidebar-trigger {
+    display: none;
+  }
+}
+
 .glass-panel {
   background:
     linear-gradient(180deg, hsl(243 42% 12% / 0.88), hsl(236 48% 5% / 0.92)),

web/src/lib/api.ts

@@ -1,6 +1,8 @@
 export type ChatSummary = {
   id: string;
   title: string | null;
+  parentChatId: string | null;
+  titleGenerationPending: boolean;
   createdAt: string;
   updatedAt: string;
   starred: boolean;
@@ -58,6 +60,8 @@ export type ToolCallEvent = {
 export type ChatDetail = {
   id: string;
   title: string | null;
+  parentChatId: string | null;
+  titleGenerationPending: boolean;
   createdAt: string;
   updatedAt: string;
   starred: boolean;
@@ -149,7 +153,7 @@ export type CompletionRequestMessage = {
   attachments?: ChatAttachment[];
 };
 
-export type Provider = "openai" | "anthropic" | "xai" | "hermes-agent";
+export type Provider = "openai" | "anthropic" | "xai" | "gemini" | "hermes-agent";
 
 export type ProviderModelInfo = {
   models: string[];
@@ -291,6 +295,14 @@ export async function getChat(chatId: string) {
   return data.chat;
 }
 
+export async function forkChat(chatId: string, messageId?: string) {
+  const data = await api<{ chat: ChatSummary }>(`/v1/chats/${chatId}/fork`, {
+    method: "POST",
+    body: JSON.stringify(messageId ? { messageId } : {}),
+  });
+  return data.chat;
+}
+
 export async function updateChatTitle(chatId: string, title: string) {
   const data = await api<{ chat: ChatSummary }>(`/v1/chats/${chatId}`, {
     method: "PATCH",
@@ -450,6 +462,7 @@ async function readSseStream(response: Response, dispatch: (eventName: string, p
   let buffer = "";
   let eventName = "message";
   let dataLines: string[] = [];
+  let sawTerminalEvent = false;
 
   const flushEvent = () => {
     if (!dataLines.length) {
@@ -466,6 +479,9 @@ async function readSseStream(response: Response, dispatch: (eventName: string, p
     }
 
     dispatch(eventName, payload);
+    if (eventName === "done" || eventName === "error") {
+      sawTerminalEvent = true;
+    }
 
     dataLines = [];
     eventName = "message";
@@ -505,6 +521,10 @@ async function readSseStream(response: Response, dispatch: (eventName: string, p
     }
   }
   flushEvent();
+
+  if (!sawTerminalEvent) {
+    throw new Error("Stream disconnected before completion");
+  }
 }
 
 export async function runSearchStream(
@@ -528,87 +548,14 @@ export async function runSearchStream(
     signal: options?.signal,
   });
 
-  if (!response.ok) {
-    const fallback = `${response.status} ${response.statusText}`;
-    let message = fallback;
-    try {
-      const body = (await response.json()) as { message?: string };
-      if (body.message) message = body.message;
-    } catch {
-      // keep fallback message
-    }
-    throw new Error(message);
-  }
-
-  if (!response.body) {
-    throw new Error("No response stream");
-  }
-
-  const reader = response.body.getReader();
-  const decoder = new TextDecoder();
-  let buffer = "";
-  let eventName = "message";
-  let dataLines: string[] = [];
-
-  const flushEvent = () => {
-    if (!dataLines.length) {
-      eventName = "message";
-      return;
-    }
-
-    const dataText = dataLines.join("\n");
-    let payload: any = null;
-    try {
-      payload = JSON.parse(dataText);
-    } catch {
-      payload = { message: dataText };
-    }
-
+  await readSseStream(response, (eventName, payload) => {
     if (eventName === "search_results") handlers.onSearchResults?.(payload);
     else if (eventName === "search_error") handlers.onSearchError?.(payload);
     else if (eventName === "answer") handlers.onAnswer?.(payload);
     else if (eventName === "answer_error") handlers.onAnswerError?.(payload);
     else if (eventName === "done") handlers.onDone?.(payload);
     else if (eventName === "error") handlers.onError?.(payload);
-
-    dataLines = [];
-    eventName = "message";
-  };
-
-  while (true) {
-    const { value, done } = await reader.read();
-    if (done) break;
-
-    buffer += decoder.decode(value, { stream: true });
-    let newlineIndex = buffer.indexOf("\n");
-
-    while (newlineIndex >= 0) {
-      const rawLine = buffer.slice(0, newlineIndex);
-      buffer = buffer.slice(newlineIndex + 1);
-      const line = rawLine.endsWith("\r") ? rawLine.slice(0, -1) : rawLine;
-
-      if (!line) {
-        flushEvent();
-      } else if (line.startsWith("event:")) {
-        eventName = line.slice("event:".length).trim();
-      } else if (line.startsWith("data:")) {
-        dataLines.push(line.slice("data:".length).trimStart());
-      }
-
-      newlineIndex = buffer.indexOf("\n");
-    }
-  }
-
-  buffer += decoder.decode();
-  if (buffer.length) {
-    const line = buffer.endsWith("\r") ? buffer.slice(0, -1) : buffer;
-    if (line.startsWith("event:")) {
-      eventName = line.slice("event:".length).trim();
-    } else if (line.startsWith("data:")) {
-      dataLines.push(line.slice("data:".length).trimStart());
-    }
-  }
-  flushEvent();
+  });
 }
 
 export async function attachSearchStream(searchId: string, handlers: RunSearchStreamHandlers, options?: { signal?: AbortSignal }) {
@@ -654,6 +601,7 @@ export async function runCompletionStream(
   body: {
     chatId?: string | null;
     persist?: boolean;
+    clientRequestId?: string;
     provider: Provider;
     model: string;
     messages: CompletionRequestMessage[];
@@ -679,86 +627,13 @@ export async function runCompletionStream(
     signal: options?.signal,
   });
 
-  if (!response.ok) {
-    const fallback = `${response.status} ${response.statusText}`;
-    let message = fallback;
-    try {
-      const body = (await response.json()) as { message?: string };
-      if (body.message) message = body.message;
-    } catch {
-      // keep fallback message
-    }
-    throw new Error(message);
-  }
-
-  if (!response.body) {
-    throw new Error("No response stream");
-  }
-
-  const reader = response.body.getReader();
-  const decoder = new TextDecoder();
-  let buffer = "";
-  let eventName = "message";
-  let dataLines: string[] = [];
-
-  const flushEvent = () => {
-    if (!dataLines.length) {
-      eventName = "message";
-      return;
-    }
-
-    const dataText = dataLines.join("\n");
-    let payload: any = null;
-    try {
-      payload = JSON.parse(dataText);
-    } catch {
-      payload = { message: dataText };
-    }
-
+  await readSseStream(response, (eventName, payload) => {
     if (eventName === "meta") handlers.onMeta?.(payload);
     else if (eventName === "tool_call") handlers.onToolCall?.(payload);
     else if (eventName === "delta") handlers.onDelta?.(payload);
     else if (eventName === "done") handlers.onDone?.(payload);
     else if (eventName === "error") handlers.onError?.(payload);
-
-    dataLines = [];
-    eventName = "message";
-  };
-
-  while (true) {
-    const { value, done } = await reader.read();
-    if (done) break;
-
-    buffer += decoder.decode(value, { stream: true });
-    let newlineIndex = buffer.indexOf("\n");
-
-    while (newlineIndex >= 0) {
-      const rawLine = buffer.slice(0, newlineIndex);
-      buffer = buffer.slice(newlineIndex + 1);
-      const line = rawLine.endsWith("\r") ? rawLine.slice(0, -1) : rawLine;
-
-      if (!line) {
-        flushEvent();
-      } else if (line.startsWith("event:")) {
-        eventName = line.slice("event:".length).trim();
-      } else if (line.startsWith("data:")) {
-        dataLines.push(line.slice("data:".length).trimStart());
-      }
-
-      newlineIndex = buffer.indexOf("\n");
-    }
-  }
-
-  buffer += decoder.decode();
-  if (buffer.length) {
-    const line = buffer.endsWith("\r") ? buffer.slice(0, -1) : buffer;
-    if (line.startsWith("event:")) {
-      eventName = line.slice("event:".length).trim();
-    } else if (line.startsWith("data:")) {
-      dataLines.push(line.slice("data:".length).trimStart());
-    }
-  }
-  flushEvent();
+  });
 }
 
 export async function attachCompletionStream(chatId: string, handlers: CompletionStreamHandlers, options?: { signal?: AbortSignal }) {

web/src/lib/chat-forking.ts

@@ -0,0 +1,82 @@
+export type ForkGroupingItem = {
+  kind: "chat" | "search";
+  id: string;
+  parentChatId: string | null;
+};
+
+type ChatTitleState = {
+  title: string | null;
+  titleGenerationPending: boolean;
+};
+
+type ForkPresentationItem = ForkGroupingItem & {
+  updatedAt: string;
+  starred: boolean;
+  starredAt: string | null;
+};
+
+export function groupForkedChatItems<T extends ForkGroupingItem>(items: T[]): T[][] {
+  const groups = new Map<string, { firstIndex: number; items: Array<{ item: T; index: number }> }>();
+
+  items.forEach((item, index) => {
+    const groupKey = item.kind === "chat" ? `chat:${item.parentChatId ?? item.id}` : `search:${item.id}`;
+    const group = groups.get(groupKey);
+    if (group) {
+      group.items.push({ item, index });
+      return;
+    }
+    groups.set(groupKey, { firstIndex: index, items: [{ item, index }] });
+  });
+
+  return [...groups.values()]
+    .sort((a, b) => a.firstIndex - b.firstIndex)
+    .map((group) =>
+      group.items
+        .sort((a, b) => {
+          const aIsRoot = a.item.kind === "chat" && a.item.parentChatId === null;
+          const bIsRoot = b.item.kind === "chat" && b.item.parentChatId === null;
+          if (aIsRoot !== bIsRoot) return aIsRoot ? -1 : 1;
+          return a.index - b.index;
+        })
+        .map(({ item }) => item)
+    );
+}
+
+export function filterSidebarItemsWithForkGroups<T extends ForkGroupingItem>(items: T[], matches: (item: T) => boolean): T[] {
+  return groupForkedChatItems(items)
+    .flatMap((group) => {
+      const matchingItems = group.filter(matches);
+      if (!matchingItems.length) return [];
+      const root = group.find((item) => item.kind === "chat" && item.parentChatId === null);
+      if (!root || matchingItems.includes(root)) return group;
+      return group.filter((item) => item === root || matchingItems.includes(item));
+    });
+}
+
+export function getForkGroupPresentation<T extends ForkPresentationItem>(groupItems: T[], allItems: T[]) {
+  const firstItem = groupItems[0];
+  if (!firstItem) return null;
+
+  const rootId = firstItem.kind === "chat" ? firstItem.parentChatId ?? firstItem.id : null;
+  const familyItems = rootId
+    ? allItems.filter((item) => item.kind === "chat" && (item.id === rootId || item.parentChatId === rootId))
+    : groupItems;
+  const updatedAt = familyItems.reduce(
+    (newest, item) => (new Date(item.updatedAt).getTime() > new Date(newest).getTime() ? item.updatedAt : newest),
+    firstItem.updatedAt
+  );
+  const starOwner = rootId
+    ? familyItems.find((item) => item.kind === "chat" && item.parentChatId === null)
+    : firstItem;
+
+  return {
+    updatedAt,
+    starred: starOwner?.starred ?? false,
+    starredAt: starOwner?.starredAt ?? null,
+  };
+}
+
+export function shouldRequestChatTitle(chat: ChatTitleState | null | undefined, isRequestInFlight: boolean) {
+  if (!chat || isRequestInFlight) return false;
+  return chat.titleGenerationPending || !chat.title?.trim();
+}

web/src/lib/chat-model-selection.ts

@@ -0,0 +1,24 @@
+import type { Provider } from "./api";
+
+type PersistedChatModel = {
+  lastUsedProvider: Provider | null;
+  lastUsedModel: string | null;
+};
+
+export type ChatModelSelection = {
+  provider: Provider;
+  model: string;
+};
+
+export function getChatModelSelection(chat: PersistedChatModel | null): ChatModelSelection | null {
+  if (!chat?.lastUsedProvider || !chat.lastUsedModel?.trim()) return null;
+  return {
+    provider: chat.lastUsedProvider,
+    model: chat.lastUsedModel.trim(),
+  };
+}
+
+export function getChatModelSelectionSyncKey(chatId: string | null, selection: ChatModelSelection | null) {
+  if (!chatId || !selection) return null;
+  return JSON.stringify([chatId, selection.provider, selection.model]);
+}

web/src/lib/sidebar-selection.ts

@@ -0,0 +1,31 @@
+export type SidebarSelection = { kind: "chat" | "search"; id: string };
+
+type WorkspaceSelectionItem = { type: SidebarSelection["kind"]; id: string };
+
+type ResolveSidebarSelectionOptions = {
+  initialSelection?: SidebarSelection;
+  selectFallback?: boolean;
+};
+
+export function resolveSidebarSelectionAfterRefresh(
+  current: SidebarSelection | null,
+  workspaceItems: WorkspaceSelectionItem[],
+  { initialSelection, selectFallback = false }: ResolveSidebarSelectionOptions = {}
+): SidebarSelection | null {
+  const hasItem = (candidate: SidebarSelection | null | undefined) => {
+    if (!candidate) return false;
+    return workspaceItems.some((item) => item.type === candidate.kind && item.id === candidate.id);
+  };
+
+  if (hasItem(current)) {
+    return current;
+  }
+  if (hasItem(initialSelection)) {
+    return initialSelection ?? null;
+  }
+  if (!selectFallback) {
+    return null;
+  }
+  const first = workspaceItems[0];
+  return first ? { kind: first.type, id: first.id } : null;
+}

web/src/pwa.ts

@@ -2,8 +2,11 @@ export function registerServiceWorker() {
   if (!import.meta.env.PROD || !("serviceWorker" in navigator)) return;
 
   window.addEventListener("load", () => {
-    void navigator.serviceWorker.register("/sw.js").catch((error: unknown) => {
-      console.warn("Sybil service worker registration failed", error);
-    });
+    void navigator.serviceWorker
+      .register("/sw.js", { updateViaCache: "none" })
+      .then((registration) => registration.update())
+      .catch((error: unknown) => {
+        console.warn("Sybil service worker registration failed", error);
+      });
   });
 }

web/tests/chat-forking.test.mjs

@@ -0,0 +1,59 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import {
+  filterSidebarItemsWithForkGroups,
+  getForkGroupPresentation,
+  groupForkedChatItems,
+  shouldRequestChatTitle,
+} from "../src/lib/chat-forking.ts";
+
+const root = { kind: "chat", id: "root", parentChatId: null };
+const firstFork = { kind: "chat", id: "first-fork", parentChatId: "root" };
+const nestedFork = { kind: "chat", id: "nested-fork", parentChatId: "root" };
+const search = { kind: "search", id: "search", parentChatId: null };
+
+test("fork groups are positioned by their newest member and always render root first", () => {
+  assert.deepEqual(groupForkedChatItems([nestedFork, search, root, firstFork]), [
+    [root, nestedFork, firstFork],
+    [search],
+  ]);
+});
+
+test("sidebar filtering keeps a matching fork with its root", () => {
+  assert.deepEqual(
+    filterSidebarItemsWithForkGroups([search, root, firstFork, nestedFork], (item) => item.id === "nested-fork"),
+    [root, nestedFork]
+  );
+});
+
+test("sidebar filtering keeps all children when their root matches", () => {
+  assert.deepEqual(
+    filterSidebarItemsWithForkGroups([search, root, firstFork, nestedFork], (item) => item.id === "root"),
+    [root, firstFork, nestedFork]
+  );
+});
+
+test("a filtered family keeps its full-family date and root-owned star state", () => {
+  const fullFamily = [
+    { ...root, updatedAt: "2026-08-10T00:00:00.000Z", starred: true, starredAt: "2026-08-15T00:00:00.000Z" },
+    { ...firstFork, updatedAt: "2026-08-11T00:00:00.000Z", starred: false, starredAt: null },
+    { ...nestedFork, updatedAt: "2026-08-16T00:00:00.000Z", starred: false, starredAt: null },
+  ];
+  const filteredFamily = [fullFamily[0], fullFamily[1]];
+
+  assert.deepEqual(getForkGroupPresentation(filteredFamily, fullFamily), {
+    updatedAt: "2026-08-16T00:00:00.000Z",
+    starred: true,
+    starredAt: "2026-08-15T00:00:00.000Z",
+  });
+});
+
+test("a fork placeholder title is replaced on its first submitted prompt", () => {
+  assert.equal(shouldRequestChatTitle({ title: "Fork of original", titleGenerationPending: true }, false), true);
+  assert.equal(shouldRequestChatTitle({ title: "Generated title", titleGenerationPending: false }, false), false);
+});
+
+test("title generation remains compatible with untitled chats and deduplicates in-flight requests", () => {
+  assert.equal(shouldRequestChatTitle({ title: null, titleGenerationPending: false }, false), true);
+  assert.equal(shouldRequestChatTitle({ title: "Fork of original", titleGenerationPending: true }, true), false);
+});

web/tests/chat-model-selection.test.mjs

@@ -0,0 +1,49 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import {
+  getChatModelSelection,
+  getChatModelSelectionSyncKey,
+} from "../src/lib/chat-model-selection.ts";
+
+test("chat model selections are normalized from persisted metadata", () => {
+  assert.deepEqual(
+    getChatModelSelection({
+      lastUsedProvider: "anthropic",
+      lastUsedModel: "  claude-sonnet-4-5  ",
+    }),
+    {
+      provider: "anthropic",
+      model: "claude-sonnet-4-5",
+    }
+  );
+});
+
+test("unrelated chat updates do not change the model synchronization key", () => {
+  const beforeSettingsSave = getChatModelSelection({
+    lastUsedProvider: "openai",
+    lastUsedModel: "gpt-4.1-mini",
+  });
+  const afterSettingsSave = getChatModelSelection({
+    lastUsedProvider: "openai",
+    lastUsedModel: "gpt-4.1-mini",
+  });
+
+  assert.equal(
+    getChatModelSelectionSyncKey("chat-1", beforeSettingsSave),
+    getChatModelSelectionSyncKey("chat-1", afterSettingsSave)
+  );
+});
+
+test("switching chats or persisted models changes the synchronization key", () => {
+  const original = { provider: "openai", model: "gpt-4.1-mini" };
+  const updated = { provider: "gemini", model: "gemini-3.5-flash" };
+
+  assert.notEqual(
+    getChatModelSelectionSyncKey("chat-1", original),
+    getChatModelSelectionSyncKey("chat-2", original)
+  );
+  assert.notEqual(
+    getChatModelSelectionSyncKey("chat-1", original),
+    getChatModelSelectionSyncKey("chat-1", updated)
+  );
+});

web/tests/sidebar-selection.test.mjs

@@ -0,0 +1,45 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { resolveSidebarSelectionAfterRefresh } from "../src/lib/sidebar-selection.ts";
+
+const workspaceItems = [
+  { type: "chat", id: "completed-chat" },
+  { type: "chat", id: "selected-chat" },
+  { type: "search", id: "selected-search" },
+];
+
+test("a collection refresh preserves the current thread selection", () => {
+  assert.deepEqual(
+    resolveSidebarSelectionAfterRefresh({ kind: "chat", id: "selected-chat" }, workspaceItems),
+    { kind: "chat", id: "selected-chat" }
+  );
+});
+
+test("an initial route selection cannot override a current thread selection", () => {
+  assert.deepEqual(
+    resolveSidebarSelectionAfterRefresh(
+      { kind: "search", id: "selected-search" },
+      workspaceItems,
+      { initialSelection: { kind: "chat", id: "completed-chat" }, selectFallback: true }
+    ),
+    { kind: "search", id: "selected-search" }
+  );
+});
+
+test("a collection refresh preserves an intentionally empty selection", () => {
+  assert.equal(resolveSidebarSelectionAfterRefresh(null, workspaceItems), null);
+});
+
+test("initial load can select the URL thread or fall back to the first item", () => {
+  assert.deepEqual(
+    resolveSidebarSelectionAfterRefresh(null, workspaceItems, {
+      initialSelection: { kind: "search", id: "selected-search" },
+      selectFallback: true,
+    }),
+    { kind: "search", id: "selected-search" }
+  );
+  assert.deepEqual(resolveSidebarSelectionAfterRefresh(null, workspaceItems, { selectFallback: true }), {
+    kind: "chat",
+    id: "completed-chat",
+  });
+});

web/tsconfig.tsbuildinfo

@@ -1 +1 @@
-{"root":["./src/App.tsx","./src/main.tsx","./src/pwa.ts","./src/root-router.tsx","./src/vite-env.d.ts","./src/components/sybil-character.tsx","./src/components/auth/auth-screen.tsx","./src/components/chat/chat-attachment-list.tsx","./src/components/chat/chat-messages-panel.tsx","./src/components/markdown/markdown-content.tsx","./src/components/search/search-results-panel.tsx","./src/components/ui/button.tsx","./src/components/ui/input.tsx","./src/components/ui/scroll-area.tsx","./src/components/ui/separator.tsx","./src/components/ui/textarea.tsx","./src/hooks/use-session-auth.ts","./src/lib/api.ts","./src/lib/utils.ts","./src/pages/search-route-page.tsx"],"version":"5.9.3"}
+{"root":["./src/App.tsx","./src/main.tsx","./src/pwa.ts","./src/root-router.tsx","./src/vite-env.d.ts","./src/components/sybil-character.tsx","./src/components/auth/auth-screen.tsx","./src/components/chat/chat-attachment-list.tsx","./src/components/chat/chat-composer.tsx","./src/components/chat/chat-messages-panel.tsx","./src/components/markdown/markdown-content.tsx","./src/components/search/search-results-panel.tsx","./src/components/ui/button.tsx","./src/components/ui/input.tsx","./src/components/ui/scroll-area.tsx","./src/components/ui/separator.tsx","./src/components/ui/textarea.tsx","./src/hooks/use-session-auth.ts","./src/lib/api.ts","./src/lib/chat-forking.ts","./src/lib/chat-model-selection.ts","./src/lib/sidebar-selection.ts","./src/lib/utils.ts","./src/pages/search-route-page.tsx"],"version":"5.9.3"}