# Recipes — using TransJakarta live data

Prerequisites: `curl` + `jq` (REST), `node` + `npm install mqtt` (live stream). Any MQTT 3.1.1-over-WSS client works (e.g. MQTTX, paho with websockets transport).

## 1. Live stream (MQTT, anonymous)

```js
// save as live.mjs; run: npm i mqtt && node live.mjs
import mqtt from 'mqtt';

const client = mqtt.connect('wss://mqtt.tj.co.id:8084/mqtt', {
  protocolVersion: 4, clean: true, connectTimeout: 15000
});

// whole fleet: '/mobile_armada/#' — or narrow to map cells, e.g. '/mobile_armada/0018-0022/#'
client.on('connect', () => client.subscribe('/mobile_armada/#', { qos: 0 }));
client.on('message', (topic, payload) => {
  const b = JSON.parse(payload.toString());
  console.log(b.bus_body_no, b.route_code, b.trip_id, b.latitude, b.longitude, b.bearing);
});
```

Notes:
- Expect a retained burst (~2,000 messages) right after subscribing, then live updates.
- `clean: true` avoids stale queues; add simple reconnect handling for long runs.
- Subscribe to specific cells instead of `#` if you only care about one area.

Ready-made snapshot tool: [[transjakarta-live-data/scripts/tj-snapshot.mjs|scripts/tj-snapshot.mjs]]
`node tj-snapshot.mjs --seconds 60 --out snapshot.json`

## 2. REST — guest token + nearby buses

```bash
# 1) guest token (no account)
TOKEN=$(curl -s -X POST 'https://tijeapi.transjakarta.co.id/v1/auth/login/guest' \
  -H 'Content-Type: application/json' -H 'Accept: application/json' \
  -H 'User-Agent: okhttp/4.12.0' -H 'X-App-OS: android' -H 'X-App-Version: 2.10.2' \
  -H 'X-Device-ID: tj-research-01' \
  -d '{"device_id":"tj-research-01"}' | jq -r .token)

# 2) nearby buses (Monas-area example)
curl -s 'https://tijeapi.transjakarta.co.id/v1/bus?latitude=-6.2088&longitude=106.8456&radius=1' \
  -H "Authorization: Bearer $TOKEN" -H 'Accept: application/json' \
  -H 'User-Agent: okhttp/4.12.0' -H 'X-App-OS: android' -H 'X-App-Version: 2.10.2' \
  -H 'X-Device-ID: tj-research-01' | jq '.data[0]'

# 3) discovery: which MQTT topics cover a location?
curl -s -X POST 'https://tijeapi.transjakarta.co.id/v1/bus' \
  -H "Authorization: Bearer $TOKEN" -H 'Content-Type: application/json' -H 'Accept: application/json' \
  -H 'User-Agent: okhttp/4.12.0' -H 'X-App-OS: android' -H 'X-App-Version: 2.10.2' \
  -H 'X-Device-ID: tj-research-01' \
  -d '{"latitude":-6.2088,"longitude":106.8456,"radius":1,"event":"change_loc"}' | jq '.data.topics'
```

- Any stable `X-Device-ID` string appears accepted; tokens last ~24 h.
- `radius` units unverified (try 1–50).

## 3. Static schedule (GTFS)

```bash
curl -LO https://gtfs.transjakarta.co.id/files/file_gtfs.zip
unzip -d gtfs file_gtfs.zip   # stops.txt, routes.txt, trips.txt, shapes.txt, stop_times.txt, ...
```

Join strategy: bus positions arrive with `trip_id` / `route_code`; use GTFS for stop names, shapes, and schedules. Feed stop IDs (`B00436P`-style) match GTFS `stop_id`.

## Cautions

- Undocumented infrastructure: endpoints can change or close without notice. Access is currently open and shared with the official app path — be gentle (one connection goes a long way; avoid aggressive polling).
- Do not open many parallel broker connections or reconnect in tight loops.
- Guest tokens expire; log in again rather than hammering the refresh endpoint.