Integration

USPS integration

USPS APIs for shipping in the United States. An agent can standardize addresses and look up ZIP Codes, price domestic and international packages, letters and extra services, compare shipping options with delivery commitments, get delivery estimates and service standards, find post offices, parcel lockers and drop-off facilities, track packages and get tracking emails or proof of delivery, manage tracking webhook subscriptions, and schedule, change or cancel carrier pickups. Not exposed: label printing, payment authorization, SCAN forms, containers and other mailer and contract APIs, and the legacy Tracking 3.0. Authentication: OAuth2 client credentials with the Consumer Key and Consumer Secret of an app in the USPS Customer Onboarding Portal; the default API product covers addresses, prices, locations, service standards, shipping options and tracking, while carrier pickup, tracking subscriptions and the service standards directory need access requested from USPS. Calls are limited by an hourly quota (HTTP 429 when exceeded). USPS terms allow the APIs and their data to be used only to facilitate USPS shipping or mailing transactions.

Connect USPS How integrations work

Ask it in chat

Say what should happen.
The workflow builds itself.

When this happens, do that in USPS.Built from the 39 USPS tools below, on the connection you add once.

What you can do with USPS

Each of these is one operation on one endpoint, available both as a workflow step and as a tool an AI agent can call on its own. Nothing bundles several operations into one action, so what a run did stays readable afterwards.

Most endpoints run on the free plan. A few, mainly the ones that publish on your behalf, need a paid plan.

Search, 11 operations

search_domestic_base_rateSearch domestic base ratePOSTGet the domestic postage price (SKU and price) for one package: mail class, processing category, rate indicator, destination entry facility, price type, weight, dimensions and ZIPs.
search_domestic_extra_service_ratesSearch domestic extra service ratesPOSTGet prices, descriptions and SKUs of domestic extra services (tracking, signature, insurance, certified mail, COD, hazmat) for a mail class and price type.
search_domestic_letter_rateSearch domestic letter ratePOSTGet the First-Class Mail price for a letter, flat or postcard (weight, dimensions, thickness, processing category), with optional extra services.
search_domestic_rate_listSearch domestic rate listPOSTList the domestic postage prices available for a package (size, weight, origin and destination ZIP), for one or more mail classes. Contract prices need accountType, accountNumber and a mail class.
search_domestic_total_ratesSearch domestic total ratesPOSTList domestic prices including extra service fees for a package (dimensions, weight, origin and destination ZIP). Without extraServices every available extra service is returned.
search_international_base_rateSearch international base ratePOSTGet the international postage price (SKU and price) for one package: mail class, processing category, rate indicator, weight and dimensions, origin ZIP and destination country.
search_international_extra_service_ratesSearch international extra service ratesPOSTGet prices of international extra services (insurance, duties-paid fee, hazmat) for a package of a given mail class, weight and destination country.
search_international_letter_rateSearch international letter ratePOSTGet the First-Class Mail International price for a letter or flat (weight, dimensions, destination country), with optional Registered Mail or Return Receipt.
search_international_rate_listSearch international rate listPOSTList the international postage rates available for a package (size, weight, origin ZIP, destination country), optionally for one mail class. Contract rates need accountType, accountNumber and a mailClass.
search_international_total_ratesSearch international total ratesPOSTList international rate options with base price plus extra service fees for a package; set requestDutiesTaxesFees with items to also get duties and taxes. Without itemValue, insurance and registered mail are not priced.
search_shipping_optionsSearch shipping optionsPOSTCompare USPS shipping options for one package in one call: prices per mail class plus delivery commitments (domestic), or prices with optional duties and taxes (international). shippingFilter keeps only the cheapest or fastest.

Subscription, 5 operations

create_tracking_subscriptionCreate tracking subscriptionPOSTSubscribe a webhook URL to tracking events for a Mailer ID or a tracking number. USPS posts events to listenerURL; an identical subscription is not duplicated. Needs Subscriptions - Tracking API access.
delete_tracking_subscriptionDelete tracking subscriptionDELETEDelete a tracking subscription. Needs the etag from get_tracking_subscription as If-Match.
get_tracking_subscriptionGet tracking subscriptionGETGet one tracking subscription by id, with its etag (needed to update or delete it).
list_tracking_subscriptionsList tracking subscriptionsGETList your tracking webhook subscriptions, optionally filtered by Mailer ID or tracking number.
update_tracking_subscriptionUpdate tracking subscriptionPUTChange the listener URL, secret or status of a tracking subscription (filters cannot change: create a new one). Send the etag from get_tracking_subscription as If-Match.

Carrier pickup, 4 operations

cancel_carrier_pickupCancel carrier pickupDELETECancel a scheduled carrier pickup by confirmation number. A cancelled pickup can no longer be updated or cancelled.
get_carrier_pickupGet carrier pickupGETGet a scheduled carrier pickup by confirmation number, with its etag (needed by update_carrier_pickup and cancel_carrier_pickup).
schedule_carrier_pickupSchedule carrier pickupPOSTSchedule a real USPS carrier pickup at an address (Monday to Saturday, until 2:00 AM CT on the pickup day, up to a year ahead). Check check_carrier_pickup_eligibility first. Needs Carrier Pickup API access.
update_carrier_pickupUpdate carrier pickupPUTChange a scheduled carrier pickup (date, packages, weight, location). Read it with get_carrier_pickup first: send its etag as If-Match and the full carrierPickupRequest with your changes.

File, 2 operations

list_location_filesList location filesGETList the bulk location files (for example all post office locations) available for download. Pass a file id to get_location_file_download_url.
list_service_standard_filesList service standard filesGETList the bulk service standard files available for download. Pass a file id to get_service_standard_file_download_url.

Generate signed url, 2 operations

get_location_file_download_urlGet location file download urlGETGet a temporary signed URL to download a location file, by the file id from list_location_files.
get_service_standard_file_download_urlGet service standard file download urlGETGet a temporary signed URL to download a service standard file, by the file id from list_service_standard_files.

Address, 1 operation

standardize_addressStandardize addressGETStandardize a US address: returns the USPS form of the street, city and state, the ZIP Code and ZIP+4, and delivery details. Give streetAddress plus state and city, or ZIPCode (or all three).

City state, 1 operation

lookup_city_stateLookup city stateGETGet the city and state for a 5-digit ZIP Code.

Dropoff location, 1 operation

list_dropoff_locationsList dropoff locationsGETFind USPS entry facilities where destination-entry parcels for a 5-digit destination ZIP Code can be dropped off, with accepted package types and drop-off times.

Eligibility, 1 operation

check_carrier_pickup_eligibilityCheck carrier pickup eligibilityGETCheck whether USPS carrier pickup is available at an address: street address plus city and state, or ZIP Code. An eligible address comes back standardized.

Estimate, 1 operation

get_delivery_estimatesGet delivery estimatesGETEstimate delivery dates between two ZIP Codes for the chosen mail classes, given the acceptance date and time. For USPS_GROUND_ADVANTAGE without a weight, two estimates come back (under and from 1 lb).

International service standard, 1 operation

get_international_service_standardGet international service standardGETGet the USPS service standard message (typical delivery time) for an international mail class to a destination country.

Notification, 1 operation

subscribe_tracking_emailsSubscribe tracking emailsPOSTRegister up to 3 email addresses to get USPS emails about a package: expected delivery, delivery activity or all updates. USPS sends those emails. Needs uniqueTrackingID from track_packages.

Parcel locker location, 1 operation

list_parcel_lockersList parcel lockersGETFind operational USPS Parcel Lockers by city and state, or by ZIP Code; returns each locker facilityID, address, coordinates, status and size limits. Paginate with offset and limit.

Post office location, 1 operation

list_post_officesList post officesGETFind post offices near an address, a city and state, a ZIP Code or a latitude/longitude, filtered by radius, office type, services offered and opening hours.

Proof of delivery, 1 operation

request_proof_of_deliveryRequest proof of deliveryPOSTHave USPS email a Proof of Delivery letter (signature image, recipient name, address) or an electronic Return Receipt for a delivered package to up to 3 addresses. Needs uniqueTrackingID from track_packages.

Reporter, 1 operation

search_service_standards_directorySearch service standards directoryPOSTGet service standard data (days to deliver) for origin and destination ZIP Codes (3 or 5 digits, lists or ranges) and mail classes. Needs Service Standards Directory API access.

Standard, 1 operation

get_service_standardsGet service standardsGETGet the average number of days a package takes between two ZIP Codes for a mail class. For USPS_GROUND_ADVANTAGE without a weight, two standards come back (under and from 1 lb).

Tracking, 1 operation

track_packagesTrack packagesPOSTGet tracking status, delivery details and scan events for one or more USPS packages by tracking number (add mailingDate or destinationZIPCode when one number matches several items).

Zip5 code, 1 operation

list_service_standard_zip_codesList service standard zip codesGETList the valid 5-digit origin and destination ZIP Codes that have service standards and are not exempt. Needs Service Standards Directory API access.

Zipcode, 1 operation

lookup_zip_codeLookup zip codeGETGet the ZIP Code and ZIP+4 for a street address, city and state (USPS state abbreviation).

Use USPS from Claude Code, Cursor or Codex

Connect USPS in LiveContext, create an API key in Settings, then add the LiveContext MCP server to your client. Its USPS operations become tools the client can call, next to every other integration you connected.

Claude Code

claude mcp add --transport http livecontext https://livecontext.ai/mcp --header "X-API-Key: YOUR_API_KEY"

Codex (~/.codex/config.toml)

[mcp_servers.livecontext]
url = "https://livecontext.ai/mcp"

[mcp_servers.livecontext.http_headers]
"X-API-Key" = "YOUR_API_KEY"

Cursor, Claude Desktop and other JSON configs

{
  "mcpServers": {
    "livecontext": {
      "type": "http",
      "url": "https://livecontext.ai/mcp",
      "headers": {
        "X-API-Key": "YOUR_API_KEY"
      }
    }
  }
}

Set up the MCP server step by step

How to connect USPS

Create your workspace
Sign up free. Nothing to install.
Connect USPS once
Add your USPS connection in Settings. Every tool from this integration reuses it, and secrets are encrypted at rest and visible only to you.
Describe the job in chat
The workflow builds itself in front of you and picks the endpoints it needs. Drag the steps yourself on the canvas whenever you would rather be explicit.