ORB-2.1: Prometheus /metrics Endpoint
| Metric | Type | Description | |--------|------|-------------| | `orbit_project_count` | Gauge | Total registered projects | | `orbit_active_sessions` | Gauge | Active Claude sessions | | `orbit_websocket_connections` | Gauge | Connected WebSocket clients | | `orbit_api_requests_total` | Counter | API requests (labels: method, path, status) | | `orbit_query_latency_seconds` | Histogram | Query latency in seconds (label: operation) |
Full Public Reader
ORB-2.1: Prometheus /metrics Endpoint
Status: COMPLETE
What was done
Added a `/metrics` endpoint to the Orbit server exposing Prometheus text exposition format.
### Dependencies added
- `metrics = "0.24"` (workspace)
- `metrics-exporter-prometheus = "0.16"` with `http-listener` feature (workspace)
### Files changed
- `Cargo.toml` — workspace dependency declarations
- `crates/orbit-server/Cargo.toml` — server-level dependency references
- `crates/orbit-server/src/metrics.rs` — NEW metrics module
- `crates/orbit-server/src/main.rs` — wired module, AppState field, recorder init, route
Metrics exposed
| Metric | Type | Description |
|---|---|---|
| `orbit_project_count` | Gauge | Total registered projects |
| `orbit_active_sessions` | Gauge | Active Claude sessions |
| `orbit_websocket_connections` | Gauge | Connected WebSocket clients |
| `orbit_api_requests_total` | Counter | API requests (labels: method, path, status) |
| `orbit_query_latency_seconds` | Histogram | Query latency in seconds (label: operation) |
### Helper functions provided
- `record_api_request(method, path, status)` — increment request counter
- `record_query_latency(operation, start)` — record histogram observation
### Validation
- `cargo check -p orbit-server` passes with zero errors
- GET `/metrics` returns `text/plain; version=0.0.4` (Prometheus format)
- Live gauges (project count, sessions, WS connections) are snapshot on each scrape
Promotion Decision
Attach run IDs, datasets, metrics, and reproduction commands.
Source Anchor
Comp-Core/apps/trajectory/trajectory-orbit/ORB-2.1-COMPLETE.md
Detected Structure
Method · Evaluation · References · Code Anchors