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Function calling is a way for a model to output structured text automatically. The structured text follows a set of user-defined variables and is formatted in JSON. It can then be used to call any other function or system. Function calling is a safe way to integrate a model with any external service, with common use-cases like:
  • Answering user queries via external API calls.
  • Converting natural language to a structured function call.
  • Extracting structured data from any text.
Tools are only available when Playground is configured with a model compatible with Function Calling. To find compatible models, look for the tools tag in the AI Router. To get started with creating tools, see:

Creating a Function Tool

Create a standard function tool.

Creating a JSON Tool

Create a JSON Schema tool.

Creating an HTTP Tool

Create an HTTP API Backed Tool.

Creating an MCP Tool

Create a Tool connecting to an MCP Server.

Creating a Python Tool

Create a tool using Python Code.
To use tools, see:

Using a tool in a Deployment

Use a tool in any Deployment.

Using a tool with an Agent

Use a tool with an Agent.