# USPS Developer Portal MCP > USPS Developer Portal connects your AI agent directly to the official United States Postal Service data. Instantly audit addresses, track packages across the country, verify ZIP codes, and calculate accurate shipping rates for domestic and international mail. It turns complex postal logistics into simple conversation. ## Overview - **Category:** industry-titans - **Price:** Free - **Tags:** address-verification, package-tracking, zip-codes, postal-services, logistics ## Description Need to manage US mailing logistics? This MCP gives your agent access to the definitive source for USPS data. You can skip manually checking websites just to confirm an address or figure out a rate. Your agent handles everything: verifying if an address is valid, looking up what ZIP code belongs to a specific city, and tracking where a package actually is right now. It takes all that complex postal knowledge—rate tables, address formatting rules, real-time delivery commitments—and makes it conversational. If you're managing e-commerce deliveries or running regional audits, your agent works like an instant logistics consultant. Once connected through Vinkius, your AI client gets access to this entire catalog of services, making sure your data is always accurate and up to date. ## Tools ### calculate_domestic_rate Figures out the cost for sending a package across state lines using USPS domestic service rates. ### calculate_international_rate Determines the shipping cost when sending a package outside of the United States. ### get_delivery_commitments Retrieves current service estimates, letting you know how quickly mail classes are expected to arrive. ### lookup_usps_city_state Finds the city and state names associated with a specific US ZIP code. ### lookup_usps_zip_code Identifies the precise, official five-digit or nine-digit ZIP code for any given mailing address. ### track_usps_package_advanced Gathers comprehensive and detailed tracking information for a USPS package shipment. ### track_usps_package Checks the current status of a package using only its primary tracking number. ### verify_usps_address Standardizes and validates an entire US address so it conforms to official USPS formatting rules. ## Prompt Examples **Prompt:** ``` Verify address '1600 Pennsylvania Avenue NW, Washington, DC 20500' using USPS. ``` **Response:** ``` I've retrieved the verification metadata from USPS! The address is identified as valid and standardized. Would you like the full XML response or the ZIP+4 metadata for this location? ``` **Prompt:** ``` Track my package with tracking number '9400100000000000000000'. ``` **Response:** ``` I've checked the status for that tracking number. It is currently identified as 'Delivered' at [Time]. I can assist you with the full event history metadata for this shipment if you'd like. ``` **Prompt:** ``` Lookup ZIP code for 'Seattle, WA'. ``` **Response:** ``` I've retrieved the ZIP code metadata for Seattle! Notable codes include 98101 and 98104. I can provide the specific address-level ZIP details to assist in your regional logistics audit. ``` ## Capabilities ### Validate US Addresses It checks and standardizes any United States address against official USPS records. ### Calculate Shipping Costs You get precise, real-time cost estimates for shipping packages both within the US and internationally. ### Monitor Package Status It retrieves detailed tracking history for USPS shipments using only a tracking number. ### Map ZIP Codes to Locations You can look up the city and state associated with any given five-digit or nine-digit ZIP code. ### Forecast Delivery Timelines It queries current service commitments, telling you estimated delivery times for various mail classes. ## Use Cases ### Pre-Sale Shipping Quote A client needs a quote for a large shipment across state lines. They ask their agent, 'What's the cost to ship 10 lbs from Texas to California?' The agent immediately uses `calculate_domestic_rate` and returns the exact price, saving minutes of manual calculation. ### Data Cleaning for Manifests An operations manager has a spreadsheet full of addresses that might be wrong. They instruct their agent to run an address audit using `verify_usps_address`, which standardizes every entry and flags any invalid records instantly. ### Tracking Missing Inventory A sales team member needs to know if a shipment is delayed. They tell their agent, 'Check the status of tracking number X.' The agent uses `track_usps_package` and provides the current status and delay details. ### Market Research for New Routes A regional auditor needs to know what ZIP codes service a major metropolitan area. They ask their agent to use `lookup_usps_zip_code` for a specific city, generating a list of relevant postal markers. ## Benefits - Stop guessing shipping costs. Use the `calculate_domestic_rate` and `calculate_international_rate` tools to get precise, real-time pricing for any package shipment. - Eliminate bad data entry. Run `verify_usps_address` on customer inputs so your records always use standardized, official USPS address formats. - Gain instant visibility into packages. Instead of calling customer service, run `track_usps_package` or `track_usps_package_advanced` to get the full event history immediately. - Boost regional knowledge with ZIP codes. The `lookup_usps_zip_code` tool lets you map a location name back to its exact postal code for auditing purposes. - Automate planning with delivery estimates. Use `get_delivery_commitments` to accurately set expectations and plan e-commerce fulfillment timelines. ## How It Works The bottom line is you use natural language prompts instead of navigating multiple postal websites and filling out forms. 1. Subscribe to the USPS Developer Portal MCP and provide your specific USPS Web Tools User ID. 2. Connect this MCP to your preferred AI client (like Claude, Cursor, or Windsurf). 3. Ask your agent a question—for example, 'What is the best rate for shipping three pounds from Miami to NYC?'—and it returns the data. ## Frequently Asked Questions **Does USPS Developer Portal MCP handle international tracking?** It handles both domestic and international rates. While it focuses on USPS services, you can calculate costs for various global destinations using the `calculate_international_rate` tool. **How do I ensure an address is correct with verify_usps_address?** Simply ask your agent to run `verify_usps_address` on the specific address string. The MCP standardizes it and confirms its validity based on official USPS records. **Can I get a cost estimate without knowing the exact weight?** You can use the `calculate_domestic_rate`, but you must provide accurate details like weight and package dimensions. The more specific you are, the better the rate estimate. **What is the best way to check if a ZIP code belongs to a state?** You should use `lookup_usps_city_state`. This tool cross-references a given ZIP code and provides the corresponding city and state data. **What kind of tracking details does track_usps_package_advanced provide?** It provides advanced, granular information. You get detailed facility-level events and comprehensive history for a package, going beyond just 'In Transit'.