Container tracking API and webhooks. Same data, right inside your system.

Who it's for

Building a TMS, an ERP or your own app?

End to end

Track a box, get the change, check the signature.

1. 1

   Start tracking

   One call per container, with the terminal code from GET /terminals.

   curl -X POST https://api.dwellzero.com/tracking \
     -H "Authorization: Bearer $DWELLZERO_KEY" \
     -H "Content-Type: application/json" \
     -d '{"terminalCode":"NWK-MAH","containerNumber":"MSCU1234566","notifyEmails":["dispatch@example.com"]}'
   
   # 201 Created
   { "success": true, "trackingId": "tracking-uuid", "status": "syncing", "isNew": true, ... }

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2. 2

   Receive container.changed

   When the box becomes available, DwellZero POSTs the event to your endpoint: the container as it is now, and what changed.

   {
     "id": "evt_8sKq2mXbV3rT0yPzL1nW4eHd",
     "event": "container.changed",
     "createdAt": "2026-10-26T18:00:05.000Z",
     "trackingId": "tracking-uuid",
     "container": {
       "containerNumber": "MSCU1234566",
       "terminalCode": "NWK-MAH",
       "terminal": "Maher Terminal",
       "location": "New Jersey",
       "status": "active",
       "lifecycle": "AVAILABLE",
       "lastFreeDay": "2026-10-30",
       "available": true,
       "transitState": "IN YARD",
       "freightReleased": true,
       "customsReleased": true,
       "hasHolds": false,
       "holds": [],
       "dischargedAt": "2026-10-25T10:00:00Z",
       "gateOutAt": null,
       "vessel": { "name": "OCEAN ANNA", "voyage": "123W" },
       "line": { "name": "Ocean Line" },
       "lastCheckedAt": "2026-10-26T18:00:00Z",
       "lastChangeAt": "2026-10-26T18:00:00Z",
       "billOfLading": "MEDU1234567"
     },
     "changes": [{ "field": "available", "oldValue": false, "newValue": true }],
     "shareUrl": "https://app.dwellzero.com/c/<token>"
   }

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3. 3

   Verify the signature

   Check it on the raw body before parsing the JSON. Node.js, no libraries:

   const crypto = require('crypto');
   
   // Express: app.post('/dwellzero/webhook', express.raw({ type: 'application/json' }), handler)
   function verifyDwellZeroWebhook(rawBody, headers, secret) {
     const id = headers['webhook-id'];
     const timestamp = headers['webhook-timestamp'];
     const signatures = headers['webhook-signature'] || '';
     const ts = Number(timestamp);
     if (!id || !timestamp || !Number.isFinite(ts) || Math.abs(Date.now() / 1000 - ts) > 300) return false; // missing, or older than 5 minutes
   
     const key = Buffer.from(secret.replace(/^whsec_/, ''), 'base64');
     const expected = crypto.createHmac('sha256', key)
       .update(`${id}.${timestamp}.${rawBody}`)
       .digest();
   
     return signatures.split(' ').some((entry) => {
       const [version, sig] = entry.split(',');
       const candidate = Buffer.from(sig || '', 'base64');
       return version === 'v1' && candidate.length === expected.length
         && crypto.timingSafeEqual(candidate, expected);
     });
   }

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   A complete Express receiver is in the webhook guide.