Documentation Index
Fetch the complete documentation index at: https://docs.langsight.dev/llms.txt
Use this file to discover all available pages before exploring further.
Usage
langsight serve [OPTIONS]
Options
| Option | Default | Description |
|---|
--host | 0.0.0.0 | Host to bind to |
--port, -p | 8000 | Port to listen on |
--config | auto-discovered | Path to .langsight.yaml |
--reload | false | Enable auto-reload (development only) |
What it does
Starts the FastAPI REST API server and (as of v0.9.0) an embedded background monitor loop. The API is used by:
- The LangSight SDK (
POST /api/traces/spans)
- OTLP integrations (
POST /api/traces/otlp)
- The dashboard
- Any custom tooling querying health/security data
Embedded monitor (v0.9.0+): langsight serve now starts a continuous health check loop in the background alongside the API. The loop runs every 60 seconds by default. Before v0.9.0, you needed a separate langsight monitor process. Control the embedded monitor with:
| Environment variable | Default | Effect |
|---|
LANGSIGHT_MONITOR_ENABLED | true | Set false to disable the embedded loop |
LANGSIGHT_MONITOR_INTERVAL_SECONDS | 60 | Seconds between health check cycles |
Start the server
Starting LangSight API on http://0.0.0.0:8000
Docs: http://localhost:8000/docs
API documentation
Once running, interactive docs are available at:
- Swagger UI:
http://localhost:8000/docs
- ReDoc:
http://localhost:8000/redoc
Endpoints
| Method | Path | Description |
|---|
| GET | /api/liveness | Instant liveness probe — no dependencies checked |
| GET | /api/readiness | Readiness probe — checks storage; returns 503 if unhealthy |
| GET | /api/status | API health check |
| GET | /api/health/servers | Latest health for all servers |
| GET | /api/health/servers/{name} | Latest health for one server |
| GET | /api/health/servers/{name}/history | Health history |
| POST | /api/health/check | Trigger on-demand health check |
| POST | /api/security/scan | Trigger security scan |
| POST | /api/traces/spans | Ingest SDK spans |
| POST | /api/traces/otlp | Ingest OTLP/JSON traces |
Authentication
When LANGSIGHT_API_KEYS is set, all routes require an X-API-Key header:
export LANGSIGHT_API_KEYS=key-abc123,key-def456 # comma-separated; any one is accepted
curl http://localhost:8000/api/health/servers \
-H "X-API-Key: key-abc123"
/api/liveness) and readiness (/api/readiness) probes are always unauthenticated — they are safe to expose to orchestrators such as Kubernetes.
Rate limits
| Endpoint | Limit |
|---|
POST /api/traces/spans | 200 req/min |
POST /api/traces/otlp | 60 req/min |
POST /api/users/verify | 10 req/min |
| All other endpoints | 200 req/min (global default) |
SlowAPIMiddleware. The global default of 200 requests/minute applies to any route without a specific override.
Production deployment
For production, use the root docker-compose.yml:
See Self-Hosting for the full production setup.
