parallel-tool-use changedagents-and-tools/tool-use/parallel-tool-use
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44description: Enable, format, and disable parallel tool calls, with message-history guidance and troubleshooting.
55featureMetadata:
66 supportedModels:
7 - claude-fable-5-2
8 - claude-mythos-5-2
79 - claude-fable-5-1
810 - claude-mythos-5-1
911 - claude-fable-5
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11561158
11571159### Exactly one tool call
11581160
1159When the `tool_choice` type is `any` or `tool`, setting `disable_parallel_tool_use: true` means Claude calls exactly one tool. Claude Opus 5.5, Claude Sonnet 5.5, Claude Fable 5.1, and Claude Mythos 5.1 don’t support these `tool_choice` types (see [Forcing tool use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/define-tools#forcing-tool-use)). The following example uses `any`. The same field works with `tool`:
1161When the `tool_choice` type is `any` or `tool`, setting `disable_parallel_tool_use: true` means Claude calls exactly one tool. Claude Fable 5.2, Claude Mythos 5.2, Claude Opus 5.5, Claude Sonnet 5.5, Claude Fable 5.1, and Claude Mythos 5.1 don’t support these `tool_choice` types (see [Forcing tool use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/define-tools#forcing-tool-use)). The following example uses `any`. The same field works with `tool`:
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11611163<CodeGroup>
11621164 ```bash cURL
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