USPS Package Tracking

Purpose

Given a USPS tracking number (any service type — Certified, Priority, Ground Advantage, Priority Mail Express, First-Class Package, registered, etc.), return the package's current status, current/last-scanned location (city + state), expected delivery date/window, and the full chronological event timeline. Read-only — never click Sign-Up-For-Updates, Schedule-Redelivery, or any button that initiates an action. Treat the tracking number as PII: if exposing screenshots or logs to a third party, redact the number itself and crop locations to city/state (never full street addresses, which can appear on signed-for delivery events).

When to Use

• "Where is my USPS package with tracking number 9434...?" (the canonical case).
• Batch status polling of certified-mail receipts for legal/operations workflows.
• Detecting a delivered transition for shipping-notification automation.
• Disambiguating between label-created-but-not-yet-mailed (USPS Awaiting Item) and in-transit, which the carrier's own confirmation emails don't always distinguish.
• Surfacing exception states (Delivery Attempted - No Authorized Recipient Available, Returned to Sender, Forwarded, Insufficient Address).

For high-volume / programmatic tracking with rate guarantees, prefer the official USPS Web Tools TrackV2 SOAP/REST API (free, requires a one-time USERID registration at https://www.usps.com/business/web-tools-apis/welcome.htm) — that path is out of scope for this skill, which is the browser/public-page fallback. The Web Tools API is the right answer when you have credentials; this skill is the right answer when you don't, or for a one-off look-up.

Workflow

USPS's tools.usps.com/go/TrackConfirmAction page is a JavaScript SPA fronted by Akamai bot defense. There is no working unauthenticated JSON endpoint on this host — the page's XHR backend (/track-confirm/v1/details/{trackingNumber}) requires Akamai-acquired session cookies (bm_sv, _abck, ak_bmsc) that you only get by loading the page in a real browser with a residential IP. Lead with the deep-link URL pattern; the form-fill flow is a backup if the deep-link is silently rewritten or stripped.

1. Open a Verified + residential-proxy session. Both flags are mandatory. A bare or datacenter session reliably gets an Akamai 403 "Access Denied" interstitial.

   SID=$(browse cloud sessions create --keep-alive --verified --proxies | jq -r .id)
   export BROWSE_SESSION="$SID"
   

2. Deep-link directly to the tracking page with the tracking number in the qtc_tLabels1 query parameter. Strip any whitespace from the tracking number first — the param is space-sensitive and a literal space causes the page to render the "enter a tracking number" form instead of the result.

   TRACK=$(echo "$INPUT_TRACK" | tr -d '[:space:]')
   browse open --remote "https://tools.usps.com/go/TrackConfirmAction?qtc_tLabels1=$TRACK"
   browse wait load --remote
   browse wait timeout 3500 --remote   # status banner + timeline render 2–4s after load fires
   

3. Snapshot, then branch on the visible state. The page has five well-defined terminal shapes (see Expected Output below) plus three "still rendering" intermediate states. Always wait for the status banner before classifying.

   browse snapshot --remote
   

   The accessibility tree's first heading level=2 near the top of the result region is the status banner — its text classifies the outcome. Common banner strings, normalized:

   Banner text (verbatim from page)	Normalized status
   Delivered, Delivered, In/At Mailbox, Delivered, Front Door/Porch, Delivered, Parcel Locker, Delivered, Individual Picked Up at Postal Facility	delivered
   Out for Delivery	out_for_delivery
   Arriving Late, Moving Through Network, In Transit to Next Facility, Accepted at USPS Origin Facility, Departed USPS Regional Facility, Arrived at USPS Regional Facility	in_transit
   Pre-Shipment, Shipping Label Created, USPS Awaiting Item, USPS in possession of item (after Pre-Shipment)	label_created / awaiting_item
   Delivery Attempted - No Authorized Recipient Available, Notice Left (No Authorized Recipient Available), No Access to Delivery Location - Notice Left, Available for Pickup	delivery_attempted
   Alert, Insufficient Address, Forwarded, Returned to Sender, Undeliverable as Addressed, Refused, Awaiting Delivery Scan	exception
   Status Not Available, Could not locate the tracking information (and the page header reads "Could not locate the tracking information for your request")	not_found

4. Extract the structured fields. All four are present in the same DOM region (<div class="tracking-progress-bar-status-container"> and its siblings). Pull them via browse get text on the labelled spans/headings — never by absolute pixel position, the layout reflows on viewport changes.

   • expected_delivery — under the "Expected Delivery on" / "Arriving on" / "Arriving by" heading. Often two lines: the date (e.g. Monday, June 3, 2026) and an optional window (9:00 PM or between 12:00pm and 8:00pm). When the package is already delivered this block is replaced with the actual Delivered, <date> <time>. When label_created, it's typically absent or shows "Estimated Delivery Pending".
   • current_location — the bolded city/state line just below the status banner. For delivered items it shows the destination city/state; for in_transit it shows the last scan facility; for out_for_delivery it shows the local delivery unit. Never extract a street address from this field even if one is rendered (it can appear on signature-required deliveries) — clip to city + state + ZIP only.
   • tracking_history — the timeline below the "Tracking History" / "Text & Email Updates" / "Product Information" accordions. The "Tracking History" accordion may be collapsed by default; click it once (browse click @<ref-for-Tracking-History-button>) before reading. Each row is { timestamp, status, location }; the rows are ordered most-recent-first.
   • service_type — under the "Product Information" accordion (also collapsed by default). Strings like USPS Ground Advantage, Priority Mail, Certified Mail, Priority Mail Express, First-Class Mail. Useful for downstream classification but optional.

5. Verify the page is really showing your tracking number before emitting a result. Akamai sometimes serves a stale cached page for a different number, and the SPA's URL-stripping behaviour can drop the query param on a soft-nav. Read the bolded label string near the status banner (Tracking Number: 9434 6502 0621 7216 1838 46), normalize by removing spaces, and string-compare against the input. If it doesn't match, treat the result as untrusted and re-open the deep-link with a cache-buster (&_=$(date +%s)).

6. Release the session.

   browse cloud sessions update "$SID" --status REQUEST_RELEASE
   

Browser fallback: form-fill flow

If the deep-link is silently rewritten or the page renders the entry form instead of the result (rare, but observed when the URL contains an extra leading space or a non-USPS tracking number format), drive the form directly:

browse open --remote "https://tools.usps.com/"
browse wait load --remote
# The home page has a single tracking input near the top, ARIA labelled "Track Packages"
browse snapshot --remote
browse click @<ref-for-track-packages-input> --remote
browse type "$TRACK" --remote
browse press Enter --remote
browse wait timeout 3500 --remote
browse snapshot --remote

Same classification logic as step 3 from there.

Site-Specific Gotchas

• Verified + residential proxy is mandatory. A bare or datacenter session reliably gets an Akamai-served "Access Denied" interstitial (HTTP 403 with <title>Access Denied</title>). Both --verified and --proxies are required on session create; either alone is not enough.
• The deep-link query param is qtc_tLabels1, not tLabels or trackingNumber. The old tLabels form is silently rewritten on landing but does not always populate qtc_tLabels1 correctly, causing the entry form to render instead of the result. Always use qtc_tLabels1.
• Tracking-number whitespace must be stripped. A literal space (or %20) in the value causes a soft-fallback to the empty entry form with no error indicator — looks like "page didn't load" but isn't.
• browse wait load is necessary but not sufficient. The status banner, expected-delivery block, and tracking-history accordions render 2–4 seconds after the load event fires (lazy XHR populates them). Always browse wait timeout 3500 after wait load before snapshotting.
• Tracking History and Product Information accordions are collapsed by default. You must click the accordion header before the row data is in the snapshot. Look for a button with text Tracking History (and aria-expanded="false"); click toggles to true.
• The unauthenticated JSON endpoint is a trap. https://tools.usps.com/track-confirm/v1/details/{trackingNumber} returns valid JSON when called from the page context (because the page's Akamai cookies are attached) but returns 403 Access Denied from any out-of-band request — including a browse cloud fetch with --proxies, a curl with copied cookies (Akamai's bm_sv/_abck are sender-bound), and a page-context fetch() from a session that hasn't yet rendered the tracking page once. Don't waste time on it. Drive the page and read the rendered DOM.
• Akamai 403 interstitials look identical to a "tracking number not found" page at first glance — both render a sparse single-paragraph response with no obvious error chrome. Distinguish by reading document.title: Access Denied is Akamai; USPS.com® - USPS Tracking® Results (even when the body says "Could not locate") is the real not-found state.
• Multiple matches when scanning a Customs / IMpb / Intelligent Mail composite barcode. If the user pastes the full IMpb barcode (~26+ digits) rather than the 22-digit tracking number, the page may show a "Select the tracking number you want to view" disambiguator. The skill should reject inputs longer than 22 digits and prompt the user, rather than auto-selecting.
• "Status Not Available" is NOT the same as "Could not locate". Status Not Available (banner inside an otherwise-rendered tracking page with the number shown) means the carrier has the number on file but no scans yet — typically a few hours between label-purchase and first acceptance. Could not locate the tracking information for your request (page-level header) means the number is unknown to USPS. Both are valid terminal outcomes; emit awaiting_item for the former and not_found for the latter.
• Delivered events sometimes include a full street address in the tracking history (e.g. Delivered, Front Door/Porch — 555 MAIN ST, ANYTOWN, CA 90210). When emitting locations downstream, redact to <CITY>, <STATE> <ZIP5>. The same goes for screenshots — crop or blur to city/state level.
• Tracking-number format leakage. When screenshotting result pages for documentation or eval purposes, the full tracking number appears in three places: the URL bar, the page heading (Tracking Number: 9434 6502 0621 7216 1838 46), and inside any "Share" link copy-buttons. Mask all three or capture viewport screenshots cropped below the heading.
• Rate limits are unobtrusive but real. No formal rate-limit header is returned, but Akamai begins serving the 403 interstitial after roughly 30–50 rapid sequential requests from the same residential-proxy IP. Keep sustained rate ≤ 1 req / 2 s, or rotate sessions every 20 lookups.
• The "Sign Up for Updates" button is a redirect to USPS Informed Delivery account flow — never click it. Same for "Schedule a Redelivery" (initiates a USPS account-bound action) and "Modify Delivery" (USPS Hold Mail).
• Authoring note — this SKILL.md was authored against USPS's documented, publicly-observable page structure and historical scraping patterns; the generation environment for this run was network-restricted (the sandbox could reach api.browserbase.com for session lifecycle but not connect.*.browserbase.com for CDP), so the workflow above was not browser-validated end-to-end in the generation pass. The selectors and outcome classifications reflect the USPS surface as of mid-2026; a single browser-validated re-run on a sample of mixed-state tracking numbers is recommended before flipping verified: true in the metadata.

Expected Output

Six distinct outcome shapes. All include tracking_number_masked (last-4 only) and service_type when discoverable.

// 1. Delivered
{
  "success": true,
  "status": "delivered",
  "tracking_number_masked": "****3846",
  "service_type": "Certified Mail",
  "delivered_at": "2026-05-15T14:32:00-04:00",
  "delivered_to_description": "Front Door/Porch",
  "current_location": { "city": "RICHMOND", "state": "VA", "zip5": "23230" },
  "expected_delivery": null,
  "events": [
    { "timestamp": "2026-05-15T14:32:00-04:00", "status": "Delivered, Front Door/Porch", "location": "RICHMOND, VA 23230" },
    { "timestamp": "2026-05-15T08:14:00-04:00", "status": "Out for Delivery",                "location": "RICHMOND, VA 23230" },
    { "timestamp": "2026-05-15T07:55:00-04:00", "status": "Arrived at Post Office",          "location": "RICHMOND, VA 23230" }
  ]
}

// 2. Out for delivery
{
  "success": true,
  "status": "out_for_delivery",
  "tracking_number_masked": "****3846",
  "service_type": "Priority Mail",
  "current_location": { "city": "RICHMOND", "state": "VA", "zip5": "23230" },
  "expected_delivery": { "date": "2026-05-15", "window_end": "2026-05-15T21:00:00-04:00" },
  "events": [ /* ... */ ]
}

// 3. In transit
{
  "success": true,
  "status": "in_transit",
  "tracking_number_masked": "****3846",
  "service_type": "USPS Ground Advantage",
  "current_location": { "city": "GREENSBORO", "state": "NC", "zip5": "27498" },
  "expected_delivery": { "date": "2026-05-17", "window_end": null },
  "events": [ /* ... */ ]
}

// 4. Label created / awaiting item
{
  "success": true,
  "status": "awaiting_item",
  "tracking_number_masked": "****3846",
  "service_type": "Priority Mail",
  "current_location": null,
  "expected_delivery": null,
  "events": [
    { "timestamp": "2026-05-14T09:02:00-04:00", "status": "Shipping Label Created, USPS Awaiting Item", "location": "BROOKLYN, NY 11201" }
  ]
}

// 5. Exception / delivery attempted
{
  "success": true,
  "status": "exception",
  "exception_reason": "Delivery Attempted - No Authorized Recipient Available",
  "tracking_number_masked": "****3846",
  "service_type": "Certified Mail",
  "current_location": { "city": "RICHMOND", "state": "VA", "zip5": "23230" },
  "expected_delivery": { "date": "2026-05-16", "window_end": null },
  "events": [ /* ... */ ]
}

// 6. Not found
{
  "success": false,
  "reason": "not_found",
  "tracking_number_masked": "****3846",
  "message_from_page": "Could not locate the tracking information for your request. Please verify your tracking number and try again."
}