Reference · built on requestConnectorShipping & logistics

USPS

Tracking, scan-event subscriptions, prices, addresses, and domestic labels from the USPS APIs under OAuth 2.0.

Request accessPricing ↗

About

The United States Postal Service publishes its APIs at developers.usps.com under OAuth 2.0. The default product covers Addresses, Domestic and International Prices, Locations, Service Standards, Shipping Options, and Tracking. Tracking 3.2 returns scan events with date, time, and location. Subscriptions - Tracking 3.2 sends new scan activity to your server URL by Mailer ID or tracking number. The Labels API creates and cancels domestic labels for USPS Ground Advantage, Priority Mail, Priority Mail Express, and other classes.

An operator on Fibric listens for scan activity on your Mailer ID, ties each event to an order, and proposes a customer reply, a label cancellation, or a return label for you to approve.

This is a reference listing. It documents what Fibric would read from USPS and what it could propose, based on the vendor's published interfaces. Fibric builds it under a managed deployment when you request it; selecting it here installs nothing.

Inputs

  • Package status, scan events with date, time, and location, and delivery expectations via POST /tracking in Tracking 3.2
  • Pushed tracking events for a Mailer ID or a tracking number through Subscriptions - Tracking 3.2, delivered to your server URL
  • Standardized addresses with ZIP + 4, plus city/state and ZIP Code lookups from Addresses 3.0
  • Domestic and International Prices for a package's characteristics, and Shipping Options in a single call
  • Service Standards: the number of days between acceptance and delivery that USPS considers timely
  • Reconciliation Adjustments by Package Identification Code, and your CRIDs, MIDs, and payment accounts from UserInfo 3.0

Proposed actions

  • Target capability: propose a domestic label through POST /label, or a return label through POST /return-label
  • Target capability: propose cancelling a label or requesting its refund through DELETE /label/{trackingNumber}
  • Target capability: propose editing weight, dimensions, or rate indicator on a created label through PATCH /label/{trackingNumber}
  • Target capability: propose a Carrier Pickup for the next USPS delivery day, or a SCAN Form linking labels under one Electronic File Number
  • Target capability: propose a tracking subscription for your Mailer ID so scan events arrive without polling

Proposed actions are target capabilities. Every action runs propose-first and needs a validated deployment and the appropriate permissions.

What you can build

  • Answer where-is-my-order from the scan feed

    Subscribe your Mailer ID to tracking events. When a customer writes in, propose a reply built from the latest scan and the expected delivery window.

    With WISMO Deflection, Stalled Shipment

  • Standardize the address before the label

    Run the ship-to address through Addresses 3.0 and propose the ZIP + 4 corrected version when it differs from what the customer typed.

    With Address Repair

  • Issue a return label on approval

    For an approved return, propose the POST /return-label request with the right mail class and attach the label to the conversation.

    With Returns Triage

Requirements

  • A USPS Business Account with a Customer Registration ID (CRID) and Mailer ID (MID)
  • An app in the Customer Onboarding Portal with a Consumer Key and Consumer Secret
  • For labels: enrollment in USPS Ship for outbound and return labels, an Enterprise Payment Account, and a Payments 3.0 payment authorization token
  • A public HTTPS server URL for Subscriptions - Tracking notifications; an HMAC secret and IP allowlisting are optional
Authentication
OAuth 2.0 client credentials (authorization code is also offered): the Consumer Key and Consumer Secret of an app registered through the USPS Customer Onboarding Portal, exchanged at /oauth2/v3/token.

Limits

  • Quotas are enforced per hour; exceeding them returns HTTP 429. Increases go through a USPS API service request
  • Tracking 3.0 is legacy and retires on July 31, 2027; new integrations use Tracking 3.2
  • A label can be canceled only before its Shipping Services File is created; afterward the same call becomes a refund request
  • Labels made in the Testing Environment for Mailers (apis-tem.usps.com) are watermarked and never billed

Access and pricing

Reference listing. Fibric builds the connector under a managed deployment when you request it. Your quote covers the build, capabilities, usage, and support.

Request USPS ↗

Questions and answers

Does USPS push tracking events?
Yes. Subscriptions - Tracking 3.2 creates a subscription by Mailer ID or tracking number and posts new scan activity to the server URL you provide. You can secure the endpoint with an HMAC secret and by accepting only USPS IP addresses. Both are optional.
What is needed to print USPS labels through the API?
Enrollment in USPS Ship for outbound and return labels and an Enterprise Payment Account. The Labels API authorizes each request with a payment authorization token issued by Payments 3.0. The Labels APIs are not in the default product; request them through a USPS API service request.
Is there a test environment?
Yes. Change the base URL from apis.usps.com to apis-tem.usps.com to reach the Testing Environment for Mailers. Labels generated there are watermarked and are not processed for payment.
Ask about USPS

Ask about the capabilities and requirements in this listing.

For project-specific requirements, contact Fibric.

This connector listing is developed, published, and supported by Fibric. It describes integration with USPS through published interfaces. Third-party names and logos identify the systems an integration connects to; they are the property of their respective owners, who are not affiliated with Fibric and do not sponsor or endorse this listing. Trademark policy