What is an MCP server?
The Model Context Protocol (MCP) is an open standard that lets AI clients such as Claude, Cursor and VS Code discover and call external tools. An MCP server publishes a list of tools with typed inputs and runs them when an agent calls them. SpecSync hosts that server for your API.
How do I turn my OpenAPI spec into an MCP server?
Give SpecSync the URL of your OpenAPI document, or paste the JSON. Each operation becomes an MCP tool whose input schema comes from its parameters and request body. You pick which tools to expose, and SpecSync gives you a hosted MCP endpoint you can add to any MCP client.
Can the MCP server run on my own domain?
Yes. Add a CNAME record pointing a hostname such as mcp.yourcompany.com at mcp.specsync.io, then verify it in the dashboard. SpecSync issues TLS automatically, and clients connect to your hostname.
How does authentication to my API work?
SpecSync doesn't ask for or store your API's credentials. The MCP client sends its own auth headers (Authorization, x-api-key or any X- header), and SpecSync forwards them to your API on each tool call.
Which spec formats are supported?
OpenAPI 3.0 and 3.1, plus Swagger 2.0, in JSON. If your spec is YAML, convert it to JSON first.
Which MCP clients can connect?
Any client that supports MCP over HTTP with Server-Sent Events. That includes Claude Code, Cursor and VS Code. Claude Desktop connects through the mcp-remote adapter.
What counts toward my monthly limit?
Each tool call made through any of your bridges counts as one request. You can see the total, and the count for each tool, on the dashboard for the current billing cycle.
Can I connect an API that runs on localhost?
Not directly, because SpecSync has to reach your API over the public internet. For testing, expose it with a tunnel such as ngrok or cloudflared and use the public URL.
What happens if my spec changes?
Bridges are generated from the spec as it was when you created them. To pick up new or changed operations, create a new bridge from the updated spec.
Is there a free plan?
Yes. You can create a bridge and try it with real clients before choosing a paid plan. Current limits are listed on the pricing section of the homepage.