Developer portal
Reference documentation for the Trackser Live API and infrastructure — the server-side system that fetches, merges and enriches TfL data for all 11 Underground lines, then serves it to the Trackser app.
Access is currently internal. The API serves the Trackser app exclusively today — keys are issued by arrangement, not self-serve. These docs describe how the system works; if you have a project that would benefit from this data, get in touch.
Every documented endpoint — live snapshots, journeys, stations, timetables and replay — with parameters and response shapes.
Read the reference →The Cloudflare Workers + Durable Object design, storage layout, cron cadence, and the request flow from edge to snapshot.
See the architecture →How TfL TrackerNet and the Unified API are polled and merged, the per-station polling model, and line coverage.
Explore data sources →Domain terms — stall detection, reformation, railway day, stopping patterns, leading car numbers and more.
Open the glossary →Endpoints are keyed by a line slug:
bakerloo central circle district hammersmith-city jubilee
metropolitan northern piccadilly victoria waterloo-city
Associated services also resolve as line IDs where relevant:
chiltern, lioness, mildmay,
weaver, windrush and elizabeth.
| Endpoint | Returns |
|---|---|
GET /live/{lineId}/map/latest.json |
Latest map-area snapshot for a line (superset including adjacent services), gzip-compressed. Primary app feed. |
GET /live/{lineId}/line/latest.json |
Latest single-line snapshot including terminals. |
GET /live/{lineId}/line/latest-stats.json |
Stats only — train count, build time, source health. No trains[] array. |
GET /live/all/line/latest.json |
All lines merged into one response. |
GET /station/{code}/board |
Live departure board across every line serving a station. |
GET /admin/status |
Per-line pipeline health snapshot. |
For technical questions, data-accuracy issues, or API-access enquiries: [email protected].