nanochat/services/chat-api

Chat API Service

Orchestration layer for samosaChaat conversations. Manages conversation state in PostgreSQL, authenticates every request via the auth service, and proxies streaming inference requests via Server-Sent Events.

Endpoints

Method	Path	Description
GET	/api/health	Liveness probe (unauthenticated)
GET	/api/conversations	List the authenticated user's conversations, grouped by date
POST	/api/conversations	Create a new conversation
GET	/api/conversations/{id}	Fetch a conversation + full message history
PUT	/api/conversations/{id}	Update the conversation title
DELETE	/api/conversations/{id}	Delete a conversation (cascade deletes messages)
POST	/api/conversations/{id}/messages	Append a user message and stream the assistant response
POST	/api/conversations/{id}/regenerate	Delete the last assistant message and regenerate it
GET	/api/models	Proxy to inference GET /models
POST	/api/models/swap	Proxy to inference POST /models/swap (admin only)

All authenticated endpoints expect Authorization: Bearer <jwt>. The chat API validates the token by calling the auth service POST /auth/validate with the shared X-Internal-API-Key header and caches the result for 5 minutes.

Environment

Variable	Default	Purpose
DATABASE_URL	postgresql+asyncpg://localhost/samosachaat	PostgreSQL connection string
AUTH_SERVICE_URL	http://auth:8001	Base URL of the auth service
INFERENCE_SERVICE_URL	http://inference:8000	Base URL of the inference service
INTERNAL_API_KEY	—	Shared key for internal service auth
MAX_CONVERSATION_HISTORY	50	Max messages included in each inference call
MAX_TOKEN_BUDGET	6000	Character budget proxy for the above
FRONTEND_URL	http://localhost:3000	Origin allowed by CORS
LOG_LEVEL	INFO	Python log level

Running locally

uv pip install -e ".[dev]"
uvicorn src.main:app --reload --port 8002

Running tests

cd services/chat-api
pytest

Tests use SQLite + aiosqlite for a throwaway database, respx to mock the auth service, and hand-crafted httpx mocks for the inference SSE stream.