llm-backend/prisma/schema.prisma

// Prisma schema for the personal chat DB + LLM call log

generator client {
  provider = "prisma-client-js"
}

datasource db {
  provider = "sqlite"
  url      = env("DATABASE_URL")
}

enum Provider {
  openai
  anthropic
  xai
}

enum MessageRole {
  system
  user
  assistant
  tool
}

model User {
  id        String   @id @default(cuid())
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  // minimal for now (single-user is fine). Keep extensible.
  handle String? @unique

  chats Chat[]
}

model Chat {
  id        String   @id @default(cuid())
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  title String?

  user   User?   @relation(fields: [userId], references: [id])
  userId String?

  messages Message[]
  calls    LlmCall[]

  @@index([userId])
}

model Message {
  id        String      @id @default(cuid())
  createdAt DateTime    @default(now())

  chat   Chat   @relation(fields: [chatId], references: [id], onDelete: Cascade)
  chatId String

  role    MessageRole
  content String

  // for tool messages or attachments later
  name     String?
  metadata Json?

  @@index([chatId, createdAt])
}

model LlmCall {
  id        String   @id @default(cuid())
  createdAt DateTime @default(now())

  chat   Chat   @relation(fields: [chatId], references: [id], onDelete: Cascade)
  chatId String

  provider Provider
  model    String

  // request/response snapshots for debugging + replay
  request  Json
  response Json?

  // usage/cost basics
  inputTokens  Int?
  outputTokens Int?
  totalTokens  Int?

  latencyMs Int?

  error   String?

  @@index([chatId, createdAt])
  @@index([provider, model, createdAt])
}