OpenAPI to AI Agent Tool Definitions Converter
Convert an OpenAPI specification into tool definitions for OpenAI-style function calling, Anthropic tool use or MCP. Free, private and instant.
How to use the OpenAPI to AI Agent Tool Definitions Converter
- Choose your file using the file picker above. It stays on your device.
- Adjust any options that appear.
- Download the finished file.
About this tool
Upload or paste an OpenAPI 3 specification in JSON or YAML. The converter turns each operation into a tool definition with a safe name, a description, and a JSON Schema for its parameters and request body, in the format you choose: OpenAI function calling, Anthropic tool use or MCP. It resolves local $ref references and warns about missing descriptions, long names and large schemas. It produces definitions only: your application still has to make the HTTP calls and handle authentication. Your spec stays in your browser.
OpenAPI to AI Agent Tool Definitions Converter is part of ToolStack Hub's Developer Tools. It runs entirely in your browser, which keeps your data private and makes results instant. There is nothing to install, no account to create and no usage limit.
Frequently asked questions
Does it call my API?
No. It only converts the specification into tool definitions. Your code makes the real HTTP requests and decides which operations the model may use.
Which OpenAPI versions work?
OpenAPI 3.x in JSON or YAML works best. Swagger 2 specs often convert, but body and parameter handling is simpler for 3.x.
Is the OpenAPI to AI Agent Tool Definitions Converter free?
Yes. OpenAPI to AI Agent Tool Definitions Converter is completely free with no sign-up, limits or watermarks.
Is my data private when I use the OpenAPI to AI Agent Tool Definitions Converter?
Yes. It runs in your browser, so your input is not uploaded to our servers.
Does it work on mobile?
Yes. ToolStack Hub tools work on phones, tablets and desktop browsers.
Keep going
Need this automated for your business?
Vantalume builds custom AI and web automation workflows so your team can stop doing repetitive work.