The tracking API that shows its work.
REST + GraphQL, HMAC-signed webhooks with a dead-letter queue, an embeddable widget, deterministic sandbox fixtures and carbon estimates — built for teams that ship.
REST API v1 + OpenAPI 3.1
Detect numbers, resolve carriers, fetch tracking surfaces and shipment events. Rate-limited per key, idempotency keys on writes, problem+json errors. Full OpenAPI spec.
API reference →Webhooks with receipts
shipment.status_changed deliveries signed with per-endpoint HMAC secrets, automatic retries, exponential redrive and a dead-letter queue you can inspect. Test-fire any webhook with one call.
Webhook docs →Deterministic sandbox
TJTEST-* numbers return byte-stable synthetic lifecycles — delivered, exception, customs hold, stale, returned — so your integration tests never depend on a real parcel.
Sandbox catalogue →Embeddable widget
Drop a tracking widget into your order-status page with a signed embed token. Your customers track without leaving your site.
Widget setup →Carbon estimates
Great-circle distance + vertical emission factors, honestly labelled as estimates, available per shipment and over the API for your ESG reporting.
Carbon endpoint →MCP server for AI agents
Twelve read-only tools — detection, carrier info, transit stats, delivery probability, timeline verification — served over Model Context Protocol for Claude and friends.
MCP docs →curl -H "Authorization: Bearer $TRACKJET_API_KEY" \
"https://trackjet.world/api/v1/track/TJTEST-DELIVERED"Early access: the API is live and free while billing is off — no card, no surprise invoices. Plans