# zipcodestack

> zipcodestack looks up postal/zip codes worldwide with location, distance, radius and geometry queries over a simple JSON REST API.

Authenticate every request with your API key via the `apikey` query parameter or request header. Base URL: https://api.zipcodestack.com

## Documentation
- [Introduction](https://zipcodestack.com/docs): Learn everything there is to know about the zipcodestack.com API and integrate zipcodestack into your product.
- [Authentication](https://zipcodestack.com/docs/authentication): In this guide, we’ll look at how authentication works. zipcodestack offers two ways to authenticate your API requests: via GET parameter or alternatively via a HTTP header.
- [Search by City Endpoint](https://zipcodestack.com/docs/city): On this page, we'll dive into the city search endpoint you can use to find postal codes for a specific city.
- [Coverage Endpoint](https://zipcodestack.com/docs/coverage): On this page, we'll dive into the coverage endpoint you can use to check postal code coverage statistics by country.
- [Zip Code Distance Endpoint](https://zipcodestack.com/docs/distance): On this page, we'll dive into the zip code distance endpoint you can use to calculate distances between zip codes.
- [Match Code Pairs Endpoint](https://zipcodestack.com/docs/match): On this page, we'll dive into the match code pairs endpoint you can use to find postal code pairs that are within a specified distance.
- [MCP Server](https://zipcodestack.com/docs/mcp): Connect AI agents to the zipcodestack API through our hosted MCP (Model Context Protocol) server.
- [Polygon Search Endpoint](https://zipcodestack.com/docs/polygon): On this page, we'll dive into the polygon search endpoint you can use to find all postal codes within a custom polygon area.
- [Get Provinces Endpoint](https://zipcodestack.com/docs/provinces): On this page, we'll dive into the provinces endpoint you can use to get a list of all states or provinces for a country.
- [Quickstart](https://zipcodestack.com/docs/quickstart): This guide will get you all set up and ready to use the zipcodestack.com API. We’ll cover how to get started an API client and how to make your first API request.
- [Radius Search Endpoint](https://zipcodestack.com/docs/radius): On this page, we'll dive into the radius search endpoint you can use to find all postal codes within a given radius.
- [Rate Limit & Quotas](https://zipcodestack.com/docs/rate-limit): In this guide, we will look at how many open connections you can have with the zipcodestack.com API.
- [SDKs](https://zipcodestack.com/docs/sdks): zipcodestack offers fine-tuned JavaScript, Ruby, PHP, Python, and Go libraries to make your life easier and give you the best experience when consuming the API.
- [Zip Code Search Endpoint](https://zipcodestack.com/docs/search): On this page, we'll dive into the zip code search endpoint you can use to validate any given zip code and retrieve its location information.
- [Search by State Endpoint](https://zipcodestack.com/docs/state): On this page, we'll dive into the state search endpoint you can use to find all postal codes within a specific state or province.
- [Status Endpoint](https://zipcodestack.com/docs/status): On this page, we’ll dive into the API status endpoint you can use to retrieve information about your request quota programmatically.
- [Request Status Codes](https://zipcodestack.com/docs/status-codes): In this guide, we will talk about what happens when something goes wrong while you work with the API.
- [Testing](https://zipcodestack.com/docs/testing): On this page, we'll dive into testing the different API responses.

## API Reference
- [OpenAPI 3.1 specification](https://zipcodestack.com/docs/openapi.yaml): Machine-readable spec for every API endpoint, parameters and responses.
- [Full documentation as markdown](https://zipcodestack.com/docs/llms-full.txt): All documentation pages concatenated as plain markdown.

## Optional
- [Pricing & plans](https://zipcodestack.com/#pricing)