php-sdk

This is the official PHP SDK for the Model Context Protocol, a framework-agnostic API for implementing MCP servers and clients in PHP. The README says it is a collaboration between the PHP Foundation and the Symfony project and follows Symfony's coding standards and backward-compatibility promise. Until the first major release it is considered experimental, with a roadmap for what comes next. Weekly conformance workflows are linked from the badges.

Install with `composer require mcp/sdk`. On the server side you define capabilities with PHP attributes (`#[McpTool]`, `#[McpResource]`), build a server with `Server::builder()`, let it auto-discover attributes in your code and run it over a transport such as stdio; other registration methods exist for different architectures. Server capabilities include tools, resources, resource templates, prompts and server-initiated communication such as elicitation, sampling, logging and progress. The README also documents transports, session management and a client SDK for connecting to MCP servers from PHP. GitHub's license detection shows none, so check the repository for the terms.