STO Express (sto)→USPS / Cross-Border Last-Mile (usps)

Track STO Express (申通快递) domestic China linehaul and cross-border USPS / last-mile handoffs.

STO Express (申通快递) handles high-volume Taobao, Tmall, 1688, and cross-border consolidation legs across China using 13-to-15-digit waybills (often starting with 77…) before handing international parcels to Cainiao, export consolidators, or USPS at destination gateways.

Try a live tracking number:

Barcode transition: STO Express to USPS / Cross-Border Last-Mile

Domestic STO Express parcels keep the same 92… / 420… barcode from pickup to mailbox. Pass ?carrier=sto to inspect middle-mile sort scans before USPS induction.

STO Express lookup →USPS / Cross-Border Last-Mile lookup →Format & check-digit detector →
Origin / middle-mile carrier
STO Express (sto)
STO Express 13–15 digit waybill (77…)
^(77\d{11,13}|\d{12,15})$
Origin example
773289104567890
Final-mile carrier
USPS / Cross-Border Last-Mile (usps)
USPS 22-digit IMpb or S10 barcode
^(92\d{20,24}|[A-Z]{2}\d{9}[A-Z]{2})$
Final-mile example
9200190302951157303009
Middle-mile resolution
Transferred to international export warehouse / USPS handoff

How the STO → USPS handoff works

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

1. Merchant pickup & STO origin sort
STO Express collects the parcel from the factory or warehouse in Yiwu, Hangzhou, or Guangzhou and assigns a 77… waybill.
2. Hub transfer (快件已发车) & export warehouse arrival
The parcel moves across STO regional hubs to the international consolidation warehouse in Dongguan, Shanghai, or Cainiao’s export hub.
3. Export linehaul & USPS final delivery
The consolidator applies an international barcode (920019… / 926129…) and hands the cleared parcel to USPS or a regional US courier.
STO Express query
GET /v1/track/773289104567890?carrier=sto
USPS last-mile query
GET /v1/track/9200190302951157303009?carrier=usps
Chinese scan normalization
Automatically maps Chinese STO scans (已揽收, 快件已发车, 已签收) to standard status enums

Chain STO → USPS in code or MCP

Resolve both legs synchronously in TypeScript, curl, or your AI support agent via Streamable HTTP MCP.

Get an API keyWISMO agent guide

REST (Synchronous GET)

# 1. Query STO Express middle-mile scans on the 92… barcode:
curl "https://api.lastscanned.com/v1/track/773289104567890?carrier=sto" \
  -H "Authorization: Bearer lsk_live_YOUR_API_KEY"

# 2. Query USPS final-mile scans on the same barcode:
curl "https://api.lastscanned.com/v1/track/9200190302951157303009" \
  -H "Authorization: Bearer lsk_live_YOUR_API_KEY"

TypeScript (Automatic Handoff Chaining)

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

// If USPS is still waiting on the consolidator parcel, query STO Express middle-mile hubs:
if (pkg.carrier === "usps" && pkg.status === "label_created" && /^(420\d{5})?9[2345]/.test(number)) {
  const mid = await fetch(`https://api.lastscanned.com/v1/track/${encodeURIComponent(number)}?carrier=sto`, { headers });
  if (mid.ok) pkg = await mid.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"

STO Express (77…) to USPS & Cross-Border Last-Mile Handoff Tracking FAQ

How do I track a 15-digit STO Express tracking number starting with 77?
Pass your 77… tracking number to GET /v1/track/{number}?carrier=sto or paste it into /lookup/sto to inspect normalized STO Express hub scans.
Why did my STO Express package mark as Delivered at a warehouse in Dongguan or Shanghai?
For Taobao Direct and cross-border consolidation orders, STO Express completes the domestic Chinese leg by delivering to the export forwarder warehouse, which then issues a new international tracking number for USPS or last-mile delivery.

Other carrier handoff guides

Explore cross-border last-mile barcode extraction and domestic USPS consolidator overrides across all 273 carriers.

"USPS Currently Awaiting Package" 92… Checker →Tracking Number Format & Check-Digit Detector →

All 273 supported carriers

Major carriers

Regional and last mile

International posts and couriers

Cross-border