OpenAPI to MCP Conversion Architecture Specification

1. Why Automated OpenAPI Translation?

With thousands of public REST APIs available across developer ecosystems, manually writing native MCP server wrappers for every API is impractical. The MCP Bridge converter automates this process by transforming OpenAPI 3.0 JSON or YAML definitions directly into MCP servers.

2. Path to Tool Schema Translation Pipeline

The converter pipeline parses OpenAPI operational paths, HTTP methods (GET, POST, PUT, DELETE), path variables, query strings, and JSON body parameters:

1. Operation ID Mapping: Each OpenAPI operation is assigned a unique MCP tool name (e.g. `POST /v1/charges` -> `stripe_create_charge`).

2. Parameter Validation: Query, header, and body schemas are converted into standard JSON Schema objects.

3. Authentication Translation: Bearer tokens, API key headers, and Basic Auth definitions are mapped to standard `env` environment variables.

{
  "name": "create_payment_intent",
  "description": "Creates a new Stripe Payment Intent payload.",
  "inputSchema": {
    "type": "object",
    "properties": {
      "amount": { "type": "integer", "description": "Amount in cents" },
      "currency": { "type": "string", "description": "Three-letter ISO currency code" }
    },
    "required": ["amount", "currency"]
  }
}

3. Running Converted Servers via Hosted Config Registries

Converted MCP configurations are published to the MCP Bridge config registry. Developers can reference hosted URLs directly in client setups or download standalone JSON files.