llm-backend

Backend API for:

• LLM multiplexer (OpenAI / Anthropic / xAI (Grok))
• Personal chat database (chats/messages + LLM call log)

Stack

• Node.js + TypeScript
• Fastify (HTTP)
• Prisma + SQLite (dev)

Quick start

cd llm-backend
cp .env.example .env
npm run db:migrate
npm run dev

Open docs: http://localhost:8787/docs

Auth

Set ADMIN_TOKEN and send:

Authorization: Bearer <ADMIN_TOKEN>

If ADMIN_TOKEN is not set, the server runs in open mode (dev).

Env

• OPENAI_API_KEY
• ANTHROPIC_API_KEY
• XAI_API_KEY

API

• GET /health
• GET /v1/chats
• POST /v1/chats
• GET /v1/chats/:chatId
• POST /v1/chats/:chatId/messages
• POST /v1/chat-completions
• POST /v1/chat-completions/stream (SSE)

POST /v1/chat-completions body example:

{
  "chatId": "<optional chat id>",
  "provider": "openai",
  "model": "gpt-4.1-mini",
  "messages": [
    {"role":"system","content":"You are helpful."},
    {"role":"user","content":"Say hi"}
  ],
  "temperature": 0.2,
  "maxTokens": 256
}

Next steps (planned)

• Better streaming protocol compatibility (OpenAI-style chunks + cancellation)
• Tool/function calling normalization
• User accounts + per-device API keys
• Postgres support + migrations for prod
• Attachments + embeddings + semantic search