Interface ToolUseStart

Information about a tool use that is starting.

interface ToolUseStart {
    type: "toolUseStart";
    name: string;
    toolUseId: string;
    reasoningSignature?: string;
}

Properties

type: "toolUseStart"

Discriminator for tool use start.

name: string

The name of the tool being used.

toolUseId: string

Unique identifier for this tool use.

reasoningSignature?: string

Reasoning signature from thinking models (e.g., Gemini). Must be preserved and sent back to the model for multi-turn tool use.