computer-use-tool changedagents-and-tools/tool-use/computer-use-tool
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1717 - claude-sonnet-5-5
1818 - claude-sonnet-5
1919 - claude-opus-4-8
20 - claude-haiku-5-5
2021 supportedPlatforms:
2122 Claude API: ga
2223 Claude Platform on AWS: beta
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3536The computer use tool is an Anthropic-defined [client toolset](https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-reference#client-toolsets): one `{"type": "computer_toolset_20260801"}` entry in `tools` gives Claude 17 member tools such as `screenshot`, `left_click`, `type`, and `zoom`, and your application runs every call in an environment you control. It isn't currently available in [Claude Managed Agents](https://platform.claude.com/docs/en/managed-agents/tools). Claude's calls are `tool_use` blocks whose `name` is the member and which carry `"toolset_name": "computer"`, often several per turn (a [batch action](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool#batch-actions)).
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38The Python and TypeScript SDKs include a class that passes these calls to your desktop code and asks your approval callback. See [Browser and computer use with the SDK toolsets](https://platform.claude.com/docs/en/agents-and-tools/tool-use/browser-use-sdk#computer-toolset).
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3740For tasks that stay inside webpages, the [browser use tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/browser-use-tool) is the closer fit: its member tools read and act on the page itself, and it doesn't need a full desktop environment.
3841
3942<Note>
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18301833* Place one `cache_control` breakpoint after the system prompt and tool definitions, and up to three more on the last `tool_result` block of each of the most recent turns, advancing them each turn. Within a [batch action](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool#batch-actions), markers on several blocks act as a single breakpoint but each still counts toward the limit of four, so use one per turn.
18311834* Prune old screenshots in *batches*, not one each turn. Dropping a screenshot every turn changes the prefix every turn and invalidates the cache. A reasonable default is to keep the last three screenshots and prune every 25 turns, so the prefix stays byte-identical between prune events; if your screenshots exceed 2000 px on either side, choose an interval that keeps each request at 20 or fewer images.
1832* On Claude Fable 5.1, Claude Opus 5.5, and Claude Sonnet 5.5, avoid pruning on the client: removing an earlier screenshot [invalidates every later thinking block](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-in-conversation) in every request that still carries those turns. Resize screenshots to 2000 px or less per side instead, and use server-side [tool result clearing](https://platform.claude.com/docs/en/build-with-claude/context-editing#tool-result-clearing) to drop old ones from the context. If you must prune, keep [`prefix_mismatch_behavior: "drop_block"`](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-thinking-controls) set from then on; after each prune, Claude continues without the thinking produced since the pruned screenshot, on that request and every later one. On Claude Sonnet 5.5, `block_binding` works only with `thinking: {"type": "adaptive"}`. With `between_tools`, keep the history append-only, or strip the thinking blocks from the edited turn on.
1835* On Claude Fable 5.1, Claude Opus 5.5, Claude Sonnet 5.5, and Claude Haiku 5.5, avoid pruning on the client: removing an earlier screenshot [invalidates every later thinking block](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-in-conversation) in every request that still carries those turns. Resize screenshots to 2000 px or less per side instead, and use server-side [tool result clearing](https://platform.claude.com/docs/en/build-with-claude/context-editing#tool-result-clearing) to drop old ones from the context. If you must prune, keep [`prefix_mismatch_behavior: "drop_block"`](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-thinking-controls) set from then on; after each prune, Claude continues without the thinking produced since the pruned screenshot, on that request and every later one. On Claude Sonnet 5.5, `block_binding` works only with `thinking: {"type": "adaptive"}`. With `between_tools`, keep the history append-only, or strip the thinking blocks from the edited turn on. On Claude Haiku 5.5, `block_binding` works only with `thinking: {"type": "adaptive"}`; with `thinking: {"type": "disabled"}`, keep the history append-only, or strip the thinking blocks from the edited turn on.
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18341837### Diagnose click issues
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22252228## Next steps
22262229
22272230<CardGroup cols={2}>
2231 <Card title="Browser and computer use with the SDK toolsets" icon="code" href="https://platform.claude.com/docs/en/agents-and-tools/tool-use/browser-use-sdk#computer-toolset">
2232 Write a desktop driver in Python or TypeScript. The SDK runs the loop and the approval callback you pass.
2233 </Card>
2234
22282235 <Card title="Troubleshooting tool use" icon="wrench" href="https://platform.claude.com/docs/en/agents-and-tools/tool-use/troubleshooting-tool-use">
22292236 Fix the most common tool-use errors with symptom-to-fix diagnostic tables.
22302237 </Card>
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