MCP Server

zipcodestack ships a hosted Model Context Protocol (MCP) server, so AI agents and assistants can call the API as native tools — no SDK or glue code required.

https://api.zipcodestack.com/mcp

The endpoint speaks the streamable HTTP transport. Listing the available tools works without authentication; executing a tool requires your API key, sent as the apikey header. You can get a free API key here.

Connect

Using Claude Code:

claude mcp add --transport http zipcodestack https://api.zipcodestack.com/mcp --header "apikey: YOUR_API_KEY"

Or add the server to any MCP-capable client (Claude Desktop, Cursor, VS Code, ...):

{
  "mcpServers": {
    "zipcodestack": {
      "url": "https://api.zipcodestack.com/mcp",
      "headers": { "apikey": "YOUR_API_KEY" }
    }
  }
}

Available tools

The tools are generated from the same OpenAPI specification that describes the REST API, so they always match the documented endpoints, parameters and responses.

Tool	Endpoint	Description
`search`	`GET /v1/search`	Look up postal codes
`distance`	`GET /v1/distance`	Distance from one code to others
`radius`	`GET /v1/radius`	Codes within a radius
`polygon`	`POST /v1/polygon`	Codes inside a polygon
`match`	`GET /v1/match`	Match code pairs within a distance
`codesByCity`	`GET /v1/code/city`	Codes for a city
`codesByState`	`GET /v1/code/state`	Codes for a state
`provinces`	`GET /v1/country/province`	Provinces for a country
`coverage`	`GET /v1/coverage`	Coverage by country
`getStatus`	`GET /v1/status`	Account quota status

Quotas and errors

Tool calls are metered exactly like REST requests: they consume your plan quota and return the same status codes and error responses (401, 422, 429, ...). If a call fails, the tool result contains the API's error message including hints on how to proceed.