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.
LangSight uses two storage backends with distinct responsibilities. This page maps every feature to the backend(s) it requires so you can choose a deployment topology with confidence.
Quick summary
| Mode | PostgreSQL | ClickHouse | Use case |
|---|
dual (default) | Required | Required | Production — all features available |
postgres | Required | — | User management, security scanning, alerts — no span analytics |
clickhouse | — | Required | Span analytics, sessions, costs — no user management |
sqlite | — | — | Local evaluation only; not for production |
Full feature matrix
Agent tracing & sessions
| Feature | PostgreSQL | ClickHouse | Notes |
|---|
| Ingest spans via SDK | — | Required | Written to mcp_tool_calls |
langsight sessions CLI | — | Required | Aggregated from mv_agent_sessions |
| Sessions dashboard page | — | Required | |
| Session trace / call tree | — | Required | |
| Session health tags | — | Required | success, loop_detected, budget_exceeded, etc. |
| Token & cost per session | — | Required | |
langsight costs CLI | — | Required | |
| Costs dashboard page | — | Required | |
| Anomaly detection | — | Required | Uses mv_tool_reliability materialized view |
| Blast radius (lineage DAG) | — | Required | |
| Loop detection (runtime) | — | — | In-process SDK check; no storage needed |
| Budget guardrails (runtime) | — | — | In-process SDK check; no storage needed |
| Circuit breaker | — | — | In-process; Redis optional for multi-worker state sharing |
MCP health monitoring
| Feature | PostgreSQL | ClickHouse | Notes |
|---|
langsight mcp-health CLI | — | Required | Health results stored in ClickHouse |
| Health dashboard page | — | Required | |
| Schema drift detection | Either | Either | schema_snapshots (Postgres/SQLite) or mcp_schema_snapshots (ClickHouse); whichever backend is active |
| Uptime / latency history | — | Required | |
| MCP server registry (config) | Required | — | Server metadata stored in PostgreSQL |
| Per-project server scoping | Required | — | |
Security scanning
| Feature | PostgreSQL | ClickHouse | Notes |
|---|
langsight security-scan CLI | Required | — | Reads server config from PostgreSQL |
| CVE scanning (OSV) | Required | — | |
| OWASP MCP Top 10 checks | Required | — | |
| Tool poisoning / prompt injection detection | Required | — | |
| Auth configuration audit | Required | — | |
| Security dashboard page | Required | — | |
SLOs & alerting
| Feature | PostgreSQL | ClickHouse | Notes |
|---|
| SLO definitions | Required | — | Stored in agent_slos |
| SLO evaluation | Required | Required | Config from PostgreSQL; span stats from ClickHouse |
| Alert rules | Required | — | |
| Alert history & deduplication | Required | — | |
| Slack alerts | Required | — | Config in PostgreSQL; payload built at runtime |
| Webhook alerts | Required | — | |
| Live view (SSE) | — | Required | Stream built from ClickHouse spans |
User management & access control
| Feature | PostgreSQL | ClickHouse | Notes |
|---|
| User accounts | Required | — | users table; passwords hashed with bcrypt |
| Invite flow | Required | — | invite_tokens table |
| RBAC (admin / viewer) | Required | — | Enforced on all write endpoints |
| Projects | Required | — | projects + project_members |
| API keys (admin / viewer scopes) | Required | — | SHA-256 hash stored; never plaintext |
| Login lockout | Required | — | login_failures table; 5 failures → 15 min lockout |
| Audit log | Required | — | audit_logs table |
Dashboard & CLI infrastructure
| Feature | PostgreSQL | ClickHouse | Notes |
|---|
| Dashboard login | Required | — | NextAuth session backed by PostgreSQL users |
| Model pricing config | Required | — | model_pricing table; editable in dashboard |
| OTLP span ingestion endpoint | — | Required | /api/traces/otlp |
Prometheus metrics (/metrics) | — | — | In-process counters; no storage |
| Liveness / readiness probes | — | — | /api/liveness, /api/readiness |
Choosing a topology
All features → dual (default)
Both backends start automatically. No further config needed.
Metadata only (no tracing yet) → postgres
storage:
mode: postgres
postgres_url: postgresql://user:pass@localhost:5432/langsight
dual when ready — existing users and projects are preserved.
Analytics only (no auth yet) → clickhouse
storage:
mode: clickhouse
clickhouse_url: http://localhost:8123
clickhouse_database: langsight
Local evaluation → sqlite
No Docker needed. Metadata features work. No span analytics.
SQLite is not supported for production. Use dual mode for any shared or persistent deployment.
