hasToolCall

API Reference for hasToolCall.

Creates a stop condition that stops when any specified tool is called in the most recent step.

This function is used with stopWhen in generateText and streamText to control when a tool-calling loop should stop based on whether one of the specified tools has been invoked.

import { generateText, hasToolCall } from 'ai';

const result = await generateText({
  model: "anthropic/claude-sonnet-5.5",
  tools: {
    weather: weatherTool,
    finalAnswer: finalAnswerTool,
  },
  // Stop when the finalAnswer tool is called
  stopWhen: hasToolCall('finalAnswer'),
});

Import

import { hasToolCall } from "ai"

API Signature

Parameters

...toolNames:

string[]
One or more tool names. The stop condition triggers when any of them is called in the most recent step.

Returns

A StopCondition function that returns true when any of the specified tools is called in the most recent step. The function can be used with the stopWhen parameter in generateText and streamText.

Examples

Basic Usage

Stop when a specific tool is called:

import { generateText, hasToolCall } from 'ai';

const result = await generateText({
  model: yourModel,
  tools: {
    submitAnswer: submitAnswerTool,
    search: searchTool,
  },
  stopWhen: hasToolCall('submitAnswer'),
});

Match Multiple Tools

Stop when any of several tools is called in the most recent step:

import { generateText, hasToolCall } from 'ai';

const result = await generateText({
  model: yourModel,
  tools: {
    weather: weatherTool,
    search: searchTool,
    finalAnswer: finalAnswerTool,
  },
  stopWhen: hasToolCall('weather', 'finalAnswer'),
});

Combining with Other Conditions

You can combine multiple stop conditions in an array:

import { generateText, hasToolCall, isStepCount } from 'ai';

const result = await generateText({
  model: yourModel,
  tools: {
    weather: weatherTool,
    search: searchTool,
    finalAnswer: finalAnswerTool,
  },
  // Stop when weather tool is called OR finalAnswer is called OR after 5 steps
  stopWhen: [
    hasToolCall('weather'),
    hasToolCall('finalAnswer'),
    isStepCount(5),
  ],
});

Agent Pattern

Common pattern for agents that run until they provide a final answer:

import { generateText, hasToolCall } from 'ai';

const result = await generateText({
  model: yourModel,
  tools: {
    search: searchTool,
    calculate: calculateTool,
    finalAnswer: {
      description: 'Provide the final answer to the user',
      inputSchema: z.object({
        answer: z.string(),
      }),
      execute: async ({ answer }) => answer,
    },
  },
  stopWhen: hasToolCall('finalAnswer'),
});

See also