Make your API usable by AI agents, without guessing at the MCP spec

MCPmatic is a small set of free tools and guides for people building Model Context Protocol (MCP) servers. Everything runs in your browser. Your specs and tool lists never leave your machine.

MCP tool linter

Paste a tools/list result and get errors, warnings and notes based on the 2026-07-28 spec: names, schemas, annotations, x-mcp-header and credential-looking parameters.

Lint my tools

OpenAPI → MCP tools

Paste an OpenAPI 3.0 or 3.1 JSON spec and get one MCP tool definition per operation, with merged input schemas and suggested annotations.

Convert a spec

Guides

What is the Model Context Protocol? Hosts, clients, servers, tools and transports in plain English.
What changed in MCP 2026-07-28: the stateless core, server/discover, multi round-trip requests and what server authors need to update.
MCP tool annotations explained: readOnlyHint, destructiveHint, idempotentHint, openWorldHint and their defaults.
Add an MCP server to Claude Desktop and Cursor, with config file locations and copy-paste JSON.
MCP server security checklist drawn from the spec's own security guidance.

Why these two tools

Most teams that want an MCP server already have an HTTP API with an OpenAPI description. The slow parts are turning each operation into a well-described tool and then checking the result is something a model can use safely. The converter does the first draft. The linter checks it, or any other server's tool list, against the rules the specification actually states.

The linter's rules quote the MCP spec where the spec uses MUST or SHOULD, and are labelled as guidance where they're MCPmatic's own advice. Generated tool definitions are a starting point. Review every description and annotation before you ship.