OpenAPI to WebMCP

Turn your existing API into browser-native tools.

Mulder compiles selected OpenAPI operations into WebMCP tools. In server-backed mode, your application keeps authentication, authorization, approval, and execution.

Build your first tool See the complete flow

One OpenAPI sourceFail-closed compilationYour API keeps control

OPENAPI

Code

get: {
  operationId: "get_service_health",
  "x-webmcp-enabled": true
}

BROWSER TOOL

Code

get_service_health({
  service: "checkout-api",
  region: "us-east"
})

EXISTING API

Code

GET /api/services/checkout-api?region=us-east

One contract, one exact browser tool set.

Mulder generates deterministic names and input schemas for native WebMCP. Server-backed reads call your API normally. Writes must enter an approval-managed path.

YOUR APP

OpenAPI 3.1
-> select operations
-> generate tools

YOUR AUTHORITY

authenticate user
-> authorize request
-> approve writes
-> execute existing API

See the real integration.

The checked demo shows browser discovery and a tool call. The generated tool list is ordinary JSON you can inspect before opening a supported browser.

Mulder’s checked browser proof