> **Experimental**
>
> `@aws-cdk/aws-bedrock-alpha` is an [**experimental**](/stability) (alpha) package: its API may change in any release, without a major version bump.
# ToolChoice

Defines how the model should choose which tool to use.

- Stability: [Experimental](/cdk/api/stability.html)
- Source: [`bedrock/prompts/tool-choice.ts`](https://github.com/aws/aws-cdk/blob/v2.274.0-alpha.0/packages/@aws-cdk/aws-bedrock-alpha/bedrock/prompts/tool-choice.ts#L80)

## Example

```ts
const cmk = new kms.Key(this, 'cmk', {});

const variantChat = bedrock.PromptVariant.chat({
  variantName: 'variant1',
  model: bedrock.BedrockFoundationModel.ANTHROPIC_CLAUDE_3_5_SONNET_V1_0,
  messages: [
    bedrock.ChatMessage.user('From now on, you speak Japanese!'),
    bedrock.ChatMessage.assistant('Konnichiwa!'),
    bedrock.ChatMessage.user('From now on, you speak {{language}}!'),
  ],
  system: 'You are a helpful assistant that only speaks the language you`re told.',
  promptVariables: ['language'],
  toolConfiguration: {
    toolChoice: bedrock.ToolChoice.AUTO,
    tools: [
      bedrock.Tool.function({
        name: 'top_song',
        description: 'Get the most popular song played on a radio station.',
        inputSchema: {
          type: 'object',
          properties: {
            sign: {
              type: 'string',
              description: 'The call sign for the radio station for which you want the most popular song. Example calls signs are WZPZ and WKR.',
            },
          },
          required: ['sign'],
        },
      }),
    ],
  },
});

new bedrock.Prompt(this, 'prompt1', {
  promptName: 'prompt-chat',
  description: 'my first chat prompt',
  defaultVariant: variantChat,
  variants: [variantChat],
  kmsKey: cmk,
});
```

## Initializer

```ts
new ToolChoice(any: any, auto: any, tool?: string)
```

## Properties

- `any`: any — Configuration for ANY tool choice.

- `ANY`: [ToolChoice](/cdk/api/v2/docs/@aws-cdk_aws-bedrock-alpha.ToolChoice.html) (required) (static) — The model must request at least one tool (no text is generated).

- `auto`: any — Configuration for AUTO tool choice.

- `AUTO`: [ToolChoice](/cdk/api/v2/docs/@aws-cdk_aws-bedrock-alpha.ToolChoice.html) (required) (static) — (Default).

  The Model automatically decides if a tool should be called or whether to generate text instead.

- `tool`: string — The specific tool name if using specific tool choice.

## Methods

- `specificTool(toolName: string): ToolChoice // chainable` (static) — The Model must request the specified tool.

  Only supported by some models like Anthropic Claude 3 models.

  **Parameters**

  - `toolName` — - The name of the specific tool to use.

  **Returns:** A ToolChoice instance configured for the specific tool