United States Postal Service
The United States Postal Service (USPS) provides a modern REST API platform at developers.usps.com that gives ecommerce websites, shipping software, and logistics systems access to postal data and services. APIs cover address validation, package tracking, domestic and international shipping labels, pricing, carrier pickup scheduling, location finding, and Informed Delivery campaign management. The legacy Web Tools platform was retired January 25, 2026, with all functionality migrated to the new OAuth 2.0-secured API platform.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles United States Postal Service the way a machine reads it — 104 machine-readable artifacts across 12 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — United States Postal Service scores 58.7/100 (developing), with a separate agent-readiness read of 48/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile United States Postal Service
Each block below is one kind of artifact we hold for United States Postal Service. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 12
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
USPS International Prices API
Provides pricing for international USPS products based on shipment characteristics including destination country, weight, dimensions, and service class.
USPS Domestic Labels API
Creates domestic shipping labels with barcodes in multiple formats and generates Shipping Services Files. Requires USPS Ship enrollment and Enterprise Payment Account.
USPS International Labels API
Creates international shipping labels and generates required Shipping Services Files for customs compliance.
USPS Locations API
Identifies drop-off facilities and destination entry points for various USPS services. Supports post office locator and drop-off location finder.
USPS Service Standards API
Provides delivery benchmarks showing expected transit times between origin and destination ZIP Codes for USPS mail classes.
USPS Shipping Options API
Returns a comprehensive list of pricing, service standards, and shipping options for USPS products in a single API call, eliminating the need to query multiple APIs separately.
USPS SCAN Forms API
Links multiple domestic and international labels through a single electronic file number, creating Shipment Confirmation Acceptance Notice forms for batch shipping operations.
USPS OAuth API
Industry-standard OAuth 2.0 Client Credentials authentication protecting access to all USPS APIs. Returns Bearer Tokens used in the Authorization header for all USPS API calls.
United States Postal Service Addresses API
Address validation and standardization operations
United States Postal Service Carrier Pickup API
Schedule and manage USPS carrier pickup requests
United States Postal Service Domestic Prices API
Domestic postage pricing and rate calculation operations
United States Postal Service Tracking API
Package tracking status and event operations
Scroll within the panel for all 12 ·
Open Collections 4
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
USPS Addresses API
OPEN COLLECTIONUSPS Carrier Pickup API
OPEN COLLECTIONUSPS Domestic Prices API
OPEN COLLECTIONUSPS Tracking API
OPEN COLLECTIONPricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.
Published pricing tiers and plan structures.
Rate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
United States Postal Service Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Features 8
The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.
Notable capabilities this provider offers.
OAuth 2.0 Authentication
Secure API access using industry-standard OAuth 2.0 Client Credentials flow with Bearer Token authentication.
RESTful Architecture
All APIs follow RESTful conventions with JSON request and response bodies.
Sandbox Testing Environment
Testing Environment for Mailers (TEM) at apis-tem.usps.com for safe API testing before going to production.
Address Standardization
USPS Coding Accuracy Support System (CASS) compliant address validation and standardization.
Delivery Point Validation
DPV confirmation codes ensure packages can be delivered to the validated address.
Real-Time Tracking
Live package tracking with scan events, timestamps, and location details from USPS systems.
Webhook Subscriptions
Event-driven subscription APIs for tracking events, adjustments, and disputes delivered via webhooks.
Batch Processing
Support for bulk operations including multiple tracking lookups and SCAN Form generation.
Scroll within the panel for all 8 ·
Semantic Vocabularies 4
JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.
JSON-LD contexts and semantic vocabularies used across these APIs.
Spectral Rules 2
Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.
JSON Schema 18
Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.
Standalone JSON Schema definitions for this provider's data models.
Address
JSON SCHEMACityState
JSON SCHEMAZIPCodeResult
JSON SCHEMAPickupAddress
JSON SCHEMAPickupPackage
JSON SCHEMAPickupRequest
JSON SCHEMAPickupResponse
JSON SCHEMAPickupUpdateRequest
JSON SCHEMABaseRateRequest
JSON SCHEMAExtraServiceRateRequest
JSON SCHEMAExtraServiceRateResponse
JSON SCHEMARateResponse
JSON SCHEMATotalRateRequest
JSON SCHEMATotalRateResponse
JSON SCHEMAMultipleTrackingRequest
JSON SCHEMAMultipleTrackingResult
JSON SCHEMATrackingEvent
JSON SCHEMATrackingResult
JSON SCHEMAScroll within the panel for all 18 ·
JSON Structure 18
JSON Structure captures the data shapes in a form built for tooling — a complement to JSON Schema that keeps the model machine-legible.
JSON Structure definitions describing this provider's data shapes.
Addresses Address Structure
JSON STRUCTUREAddresses City State Structure
JSON STRUCTUREAddresses Zip Code Result Structure
JSON STRUCTURECarrier Pickup Pickup Address Structure
JSON STRUCTURECarrier Pickup Pickup Package Structure
JSON STRUCTURECarrier Pickup Pickup Request Structure
JSON STRUCTURECarrier Pickup Pickup Response Structure
JSON STRUCTURECarrier Pickup Pickup Update Request Structure
JSON STRUCTUREDomestic Prices Base Rate Request Structure
JSON STRUCTUREDomestic Prices Extra Service Rate Request Structure
JSON STRUCTUREDomestic Prices Extra Service Rate Response Structure
JSON STRUCTUREDomestic Prices Rate Response Structure
JSON STRUCTUREDomestic Prices Total Rate Request Structure
JSON STRUCTUREDomestic Prices Total Rate Response Structure
JSON STRUCTURETracking Multiple Tracking Request Structure
JSON STRUCTURETracking Multiple Tracking Result Structure
JSON STRUCTURETracking Tracking Event Structure
JSON STRUCTURETracking Tracking Result Structure
JSON STRUCTUREScroll within the panel for all 18 ·
Examples 18
Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.
Example request and response payloads for these APIs.
Addresses Address Example
EXAMPLEAddresses City State Example
EXAMPLEScroll within the panel for all 18 ·
Security Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Use Cases 8
What developers actually build with this provider — captured so the catalogue answers 'what is this for', not just 'what does this expose'.
What developers build with this provider.
E-Commerce Shipping Integration
Calculate shipping rates, generate labels, and provide package tracking directly within e-commerce checkout flows.
Address Verification at Checkout
Validate and standardize customer addresses during checkout to reduce failed deliveries and return rates.
Shipping Label Generation
Programmatically create domestic and international USPS shipping labels with barcodes for fulfillment operations.
Carrier Pickup Automation
Schedule and manage USPS carrier pickups automatically based on order fulfillment triggers.
Logistics Rate Shopping
Compare USPS service options and pricing to select the most cost-effective shipping method.
Delivery Time Estimation
Display accurate expected delivery dates to customers using USPS service standards data.
Post Office Finder
Help customers locate the nearest USPS facility for drop-offs or in-person services.
Informed Delivery Campaigns
Enhance customer engagement by adding digital content to mail pieces viewed through Informed Delivery.
Scroll within the panel for all 8 ·
Integrations 6
Pre-built integrations with other platforms tell you where this provider already fits in a stack.
Pre-built integrations with other platforms and tools.
Shopify
USPS shipping integration available through Shopify Shipping for label generation and rate calculation.
WooCommerce
WooCommerce shipping plugins integrate USPS APIs for rate calculation and label printing.
Magento
Adobe Commerce and Magento integrate USPS for shipping rate display and fulfillment.
ShipStation
ShipStation multi-carrier shipping platform integrates USPS APIs for ecommerce fulfillment.
EasyPost
EasyPost shipping API aggregator provides access to USPS services alongside other carriers.
Stamps.com
Stamps.com and Pitney Bowes shipping platforms integrate USPS APIs for postage and label printing.
Resources
Every other property we hold for United States Postal Service — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 2
Portal, sign-up, and the first successful call
Documentation 1
Reference material describing how the API behaves
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 2
Pagination, idempotency, versioning, errors, and events
Build 2
SDKs, sample code, and the tooling you integrate with
Access & Security 2
Authentication, authorization, and security posture
Operate 2
Status, limits, changes, and where to get help
Commercial 1
Pricing, plans, and the legal terms of use
Company 1
The organization behind the API
← All providers · Data indexed from github.com/api-evangelist/united-states-postal-service · machine-readable index on apis.io