Tool & function calling

Native function schemas

Declare functions in a tools array. When the model decides to use one, it stops generating text and returns the function name and arguments for you to execute.

{
  "name": "run_javascript",
  "description": "Executes JavaScript in a sandbox",
  "parameters": {
    "type": "object",
    "properties": {
      "code": { "type": "string", "description": "JS script text" }
    },
    "required": ["code"]
  }
}

The tool loop

The orchestration follows a simple loop:

• Match — the engine detects a tool call in the stream.
• Execute — generation halts and the requested tool runs.
• Format — the result is wrapped as a system message.
• Resume — the result is appended to context and generation continues.

{ "role": "system", "content": "[TOOL RESULT: Weather in New Delhi is 32°C]" }

Built-in tools

Standard dialogue completions can also trigger built-in tools by emitting a structured call in the stream:

{ "tool": "WebSearch-1", "query": "current weather in New Delhi" }

• WebSearch-1 — live web search and synthesis.
• search_internet — general internet lookup.
• run_javascript — execute code in a sandbox.

Streaming notifications

When streaming, a tool_call event is emitted so your UI can show that a tool is running before the final answer arrives. See /docs/streaming.