Ship MCP servers that models can actually use
Lint your MCP tool definitions against the spec, turn an OpenAPI document into MCP tools, and read short guides that cite the primary sources. Free, and everything runs in your browser.
- Nothing uploaded
- No cookies or trackers
- Rules cite the spec
Two tools for the slow parts of building an MCP server
Most teams wanting an MCP server already have an HTTP API. The slow part is describing each operation well, then checking the result is safe for a model to call.
MCP tool linter
Paste a
tools/listresult and get errors, warnings and notes based on the 2026-07-28 spec: names, input schemas, annotations,x-mcp-headerand credential-looking parameters.OpenAPI → MCP converter
Paste an OpenAPI 3.0 or 3.1 JSON document and get one MCP tool per operation, with merged input schemas and suggested annotations, ready to check and ship.
From API to working MCP server
A short path that keeps the model's view of your tools accurate.
- DraftConvert your OpenAPI document into tool definitions with the converter.
- CheckRun them through the linter, fix names and descriptions, and set honest annotations.
- TestImplement them with an official SDK and test with MCP Inspector before you ship.
Guides, written against the spec
Each guide states the spec version it covers and links to the primary source, with the date it was checked.
- Start here
What is the Model Context Protocol (MCP)?
Hosts, clients, servers, tools and transports in plain English.
- Start here
MCP vs function calling vs APIs
They aren't rivals. Where each one fits, and when MCP is worth a server.
- Start here
MCP server examples
Official reference servers, a minimal server, and real tool definitions.
- Build
How to test an MCP server
MCP Inspector, scripted CLI checks and a CI smoke test.
- Spec 2026-07-28
How to migrate an MCP server to spec 2026-07-28
A step-by-step upgrade path for server authors.
- Security
MCP security best practices
The attacks the spec names, and who must do what about them.
Frequently asked questions
What is MCPmatic?
MCPmatic is a free, independent site for Model Context Protocol (MCP) developers. It has two in-browser tools, an MCP tool linter and an OpenAPI to MCP converter, plus short guides written against MCP spec 2026-07-28 that cite the primary sources.
What does the MCP tool linter check?
Paste a tools/list result and the linter reports errors, warnings and notes based on the 2026-07-28 spec: tool names, input schemas, annotations, x-mcp-header and credential-looking parameters.
Can I convert an OpenAPI spec into MCP tools?
Yes. Paste an OpenAPI 3.0 or 3.1 JSON document into the OpenAPI to MCP converter and it produces one MCP tool per operation, with merged input schemas and suggested annotations, ready to check and ship.
Is anything uploaded to a server?
No. Both tools run entirely in your browser, nothing you paste is uploaded, and the site uses no cookies or trackers.
Is MCPmatic affiliated with Anthropic or the MCP project?
No. MCPmatic is an independent project and is not affiliated with or endorsed by Anthropic, the Model Context Protocol project or any vendor mentioned on the site.