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Direct REST API conversion lets you create a hosted MCP server without first writing an OpenAPI document. In 0mcp, provide your REST API details, configure the endpoints and authentication, and choose which operations should become MCP tools.

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What you configure

For each operation, define:
  • HTTP method and path
  • Purpose and tool description
  • Path, query, header, and body inputs
  • Expected response
  • Upstream authentication requirements
  • Whether the operation is read-only or changes data
Start with a small set of useful read-only operations. Add write operations after you have tested authentication, authorization, logging, and user confirmation.

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Preview before creating the server

Before creating the MCP server, 0mcp shows a preview of the generated tools. Use the preview to:
  • Confirm the upstream base URL.
  • Review detected authentication.
  • Select only the endpoints you want to expose.
  • Rename generated tool names.
  • Improve tool and input descriptions.
  • Check validation findings.
  • Download the generated OpenAPI document.
Blocking validation findings must be fixed before import. Warnings, such as missing descriptions, should be reviewed because clear metadata helps AI clients call tools correctly.

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What 0mcp provides

The direct REST workflow includes:
  • A hosted MCP endpoint
  • Tools created from selected REST operations
  • Resources and reusable prompts
  • Playground testing
  • Published versions and rollback
  • Usage analytics and activity logs
  • Setup guidance for supported MCP clients
Your REST API remains the source of truth for data, business logic, authentication, and authorization. 0mcp provides the MCP-facing adapter. If your API already has an OpenAPI 3.x or Swagger 2.0 document, you can use the OpenAPI source instead. For a detailed migration process, read From REST API to MCP server.