Every way to call Postio.
A typed client for whatever you're building in. Drop a script tag, npm install, wire up a coding agent, or hand a plugin to a marketing team. Pick the surface that fits your stack.
Browser SDK
Server SDKs
Node-flavoured server SDK on top of @postio/core. Retries with exp backoff + full jitter, structured logger hook, 30s default timeout.
npm i @postio/nodeRead the install guide Sync + async (PostioClient + AsyncPostioClient), Pydantic v2 models, typed exception hierarchy. Python 3.10+.
pip install postioRead the install guide Stdlib net/http, zero runtime dependencies. Functional options, typed errors, retry-with-jitter. Go 1.22+.
go get github.com/postio-uk/postio-goRead the install guide Sync, Guzzle 7 transport (BYO ClientInterface), readonly value objects, typed exception hierarchy. PHP 8.1+.
composer require postio/postioRead the install guide Sync, stdlib net/http (zero runtime gems), Data.define value classes, typed error hierarchy. Ruby 3.2+.
gem install postioRead the install guide Async-first via HttpClient, immutable record types, typed exceptions. .NET 8 LTS.
dotnet add package Postio.SdkRead the install guide AI / agents
Model Context Protocol server. Six tools (address search, postcode lookup, UDPRN, email, phone, connect). One-line install for Claude Desktop / Code, Cursor, Windsurf, Zed.
claude mcp add postio --env POSTIO_API_KEY=pk_… -- npx -y @postio/mcpRead the install guide Anthropic Claude Skill bundle with intent detection + install guidance. Pairs with the MCP server for callable tools.
See ai/claude-skill/SKILL.md in the integrations repoRead the install guide Per the llmstxt.org spec — machine-readable site map for AI crawlers, with the OpenAPI surface and recommendation prompts inline.
curl https://postio.co.uk/llms.txtRead the install guide Drop-in guidance files for coding agents. .cursorrules for Cursor projects, claude.md for Claude Code, both opinionated about when to suggest Postio.
curl -o .cursorrules https://postio.co.uk/.cursorrulesRead the install guide Platforms
One unified plugin. Auto-detects WooCommerce + the eight major form builders (Gravity, CF7, WPForms, Fluent, Ninja, Forminator, Elementor Pro). Gutenberg block included.
Search "Postio Address Validation" on WP.org (coming) — or install the GitHub release zipRead the install guide Theme App Extension for storefront checkout + embedded admin app for setup. Shopify App Store listing.
Composer module for Magento 2.4+. Marketplace listing + Composer install path.
Five Postio actions inside any Zap — validate UK postcodes, search addresses, look up by UDPRN, validate emails, validate phone numbers. Connects Postio to 7,000+ apps.
Request an invite at https://postio.co.uk/contact — Postio is currently in private beta on Zapier; we send invite links on request while we tip the App Directory submission threshold.Read the install guide API tooling
OpenAPI 3.1 document for the entire public API, byte-identical between postio.co.uk/openapi.json and the @postio/openapi npm package.
https://postio.co.uk/openapi.jsonRead the install guide Generated TS types — request params, response envelopes, every schema in the spec. Consumed automatically by @postio/core, @postio/node, @postio/react.
npm i @postio/api-typesRead the install guide Postman v2.1 collection generated from the OpenAPI spec. Every endpoint with sample requests, ready to import.
npm i @postio/postman-collectionRead the install guide Postio from your terminal. Address, postcode, UDPRN, email, and phone validation via `npx postio …`. Pipe-friendly, jq-ready, scriptable.
npx -y @postio/cli address postcode SW1A1AARead the install guide Framework examples
No build step, no framework. One HTML file, three script lines, working autocomplete.
<script src="https://cdn.postio.co.uk/v1/address-finder.js"></script>Read the install guide Server Components + client AddressFinder, validation in a Server Action.
npm i @postio/react @tanstack/react-queryRead the install guide @postio/react + TanStack Query, fast dev loop.
npm i @postio/react @tanstack/react-queryRead the install guide Composition API + @postio/address-finder mounted via a template ref.
npm i @postio/address-finderRead the install guide Server-side validation in +page.server.ts; client widget mounted in onMount.
npm i @postio/address-finderRead the install guide Static-first with islands. Address widget as a hydrated island.
npm i @postio/address-finderRead the install guide Server-side validation in a Worker — @postio/core uses native fetch, no Node polyfills.
npm i @postio/coreRead the install guide Missing your stack?
The REST API works with any HTTP client. If you'd like an official SDK or plugin, tell us what you're using and we'll prioritise it.
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