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LLM Tool Schema Converter

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Convert a function/tool definition between OpenAI function calling, Anthropic tool use and Gemini function declaration formats.

function calling schemaopenai tools to anthropictool use convertergemini function declaration
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Input: any of these formats, or a bare JSON Schema (set name/description below).
Continue with:
Frequently Asked Questions
How do the formats differ?
OpenAI wraps a function with "parameters", Anthropic uses "input_schema" at the top level of a tool, and Gemini uses "functionDeclarations" with its own schema subset.
Will the converted schema always work?
The core name, description and JSON Schema carry over, but providers support different JSON Schema keywords, so test with your target API.
Can I paste a list of tools?
Paste a single tool or an array; the converter handles both.
Is anything sent to a server?
No, conversion happens locally in your browser.
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