# Iris MCP > MCP servers give an Iris extra tools: git, a database, a mailbox, your own service. Each one lists its address or command, its credential references and its tools before you install it. Ours are hosted here for every house. ## Guide - [Build a shared MCP server](https://mcp.okayiris.com/docs.md): the whole guide in Markdown, including the exact format, what is refused, and how to publish. - [Catalog, JSON](/api/mcp): every entry with its newest version, tags, license and sources. - [index.json](/api/mcp/index): the same list as one object, written after every change. ## How to use one install the MCP server Every entry has a Markdown twin: https://mcp.okayiris.com/m/.md, and packages are plain JSON at https://mcp.okayiris.com/api/mcp/[/]. ## Entries - [registry](https://mcp.okayiris.com/m/registry.md): Search the shared skills and read an MCP server's entry, so an assistant can use what every other house already reconned. (by Iris, MIT, tags: knowledge, developer)