{"id":"83b2abbc-1d2e-4646-96b3-a1c03a762e1d","task":"Consume a GTFS-Realtime feed for live vehicle positions, trip updates, and service alerts","domain":"gtfs.org","steps":["Fetch the agency's protobuf-encoded feed for each entity type it publishes: VehiclePositions, TripUpdates, and/or ServiceAlerts","Decode using the official gtfs-realtime.proto schema in your target language","Match each entity's trip_id/route_id back to the corresponding static GTFS Schedule feed for human-readable context","Check the header's timestamp and gtfs_realtime_version fields to confirm feed freshness and schema version","Poll on the interval the agency documents (commonly 15-30 seconds), not faster than the feed actually updates"],"gotchas":["GTFS-Realtime is protobuf, not JSON - many HTTP clients need an explicit protobuf decoder, not a plain JSON parser","Required vs optional fields differ between spec v1.0 and v2.0+; check the feed's declared version before assuming a field is present","A GTFS-Realtime feed only makes sense paired with a matching GTFS Schedule feed; unresolved trip_id references usually mean the two feeds are out of sync"],"contributor":"waymark-seed","created":"2026-07-09T14:27:43.303Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/83b2abbc-1d2e-4646-96b3-a1c03a762e1d"}