Track 4PX parcels through customs clearance and OnTrac final-mile delivery.

4PX consolidates cross-border e-commerce parcels under an origin waybill (304170156856) and injects them into OnTrac (1LS729108273411) via LAX / EWR customs release to OnTrac sort hub. Querying lastscanned with ?carrier=4px returns origin export and linehaul events, while querying the OnTrac tracking number returns domestic final-mile delivery scans.

Try a live tracking number:

Barcode transition: 4PX to OnTrac

When 4PX clears customs and hands off to OnTrac, lastscanned surfaces the secondary tracking number in the top-level message field.

Origin / middle-mile carrier
4PX (4px)
4PX Waybill
4PX… or 12-digit numeric waybill
Origin example
304170156856
Final-mile carrier
OnTrac (ontrac)
OnTrac Barcode
1LS… or C/D + 14 digits
Final-mile example
1LS729108273411
Extracted in .message
Handed over to final-mile carrier OnTrac (1LS729108273411) — LAX / EWR customs release to OnTrac sort hub

How the 4PX → OnTrac handoff works

Follow the parcel across both networks without waiting on asynchronous webhooks or losing visibility at the handoff boundary.

1. Origin induction (4PX)
The merchant inducts the parcel into 4PX under origin tracking ID 304170156856.
2. Linehaul & customs (LAX / EWR customs release to OnTrac sort hub)
The shipment clears customs at LAX / EWR customs release to OnTrac sort hub and receives domestic OnTrac barcode 1LS729108273411.
3. Final-mile delivery (OnTrac)
OnTrac completes local regional sortation and doorstep delivery with photo confirmation.
Origin Carrier Slug
4px
Destination Carrier Slug
ontrac
Primary Injection Gateway
LAX / EWR customs release to OnTrac sort hub

Chain 4PX → OnTrac in code or MCP

Resolve both legs synchronously in TypeScript, curl, or your AI support agent via Streamable HTTP MCP. Want automatic alerts when this handoff updates? Add the tracking number in Dashboard Watches, or use the Free API (5/day), Pro ($4.99/mo for 1,000 numbers), or an Instant 25-Pack ($0.50).

REST (Synchronous GET)

# 1. Query 4PX origin waybill (extracts final-mile barcode in .message):
curl "https://api.lastscanned.com/v1/track/304170156856" \
  -H "Authorization: Bearer lsk_live_YOUR_API_KEY"

# 2. Query the extracted OnTrac barcode:
curl "https://api.lastscanned.com/v1/track/1LS729108273411" \
  -H "Authorization: Bearer lsk_live_YOUR_API_KEY"

TypeScript (Automatic Handoff Chaining)

const headers = { Authorization: `Bearer ${process.env.LASTSCANNED_API_KEY}` };
const originRes = await fetch(`https://api.lastscanned.com/v1/track/${encodeURIComponent(number)}`, { headers });
const originPkg = await originRes.json();

// Extract secondary barcode from top-level message ("Handed over to final-mile carrier OnTrac (1LS729108273411) — LAX / EWR customs release to OnTrac sort hub")
const handoff = originPkg.message?.match(/^Handed to (.+?) as ([A-Z0-9-]+)$/i);
if (handoff) {
  const [, , lastMileNumber] = handoff;
  const destRes = await fetch(`https://api.lastscanned.com/v1/track/${encodeURIComponent(lastMileNumber)}`, { headers });
  const destPkg = await destRes.json();
}

Remote MCP (Claude Code / Cursor / ChatGPT)

claude mcp add --transport http lastscanned https://mcp.lastscanned.com \
  --header "Authorization: Bearer lsk_live_YOUR_API_KEY"

4PX to OnTrac Handoff Tracking FAQ

How do I track a 4PX parcel handed off to OnTrac?
Query GET /v1/track/304170156856?carrier=4px for origin and customs milestones, and GET /v1/track/1LS729108273411?carrier=ontrac for OnTrac final-mile delivery scans.
Can I get automatic alerts when 4PX hands off to OnTrac?
Yes. Add 304170156856 or 1LS729108273411 in lastscanned Dashboard Watches at https://app.lastscanned.com/watches or subscribe via webhook.

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