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Sweep 06 Nov 2026 · 01:32Z Build v2.1.319 537 read Stable v2.1.311 Latest v2.1.319 Next v2.1.319 Feeds RSS JSON llms.txt llms-full.txt Unofficial
HomeDocsClaude Code CLI 2 Nov 2026
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Connect Claude Code to tools via MCP changedmcp

Nearest release: v2.1.317, published 2 hours after upstream edited the page. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.

Upstream edited this page at 2 Nov 2026 21:44 UTC, give or take a minute or two: the time comes from Anthropic’s own sitemap rather than from a commit. This site recorded the change at 2 Nov 2026 22:07 UTC.

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First seen 14 Aug 2026 this site's first read of the page
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18221822> * **You've set `CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS`**: see [how it affects tool search](#configure-tool-search)
18231823> * **A request failed with an error that names `defer_loading` or `tool_reference`**: see [Extra inputs are not permitted](https://code.claude.com/docs/en/errors.md#extra-inputs-are-not-permitted)
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1825When `ANTHROPIC_BASE_URL` points to a gateway, tool search is on by default, so requests include `defer_loading` tool fields and `tool_reference` blocks for the gateway to forward. While tool search is on, MCP tools are [deferred](#scale-with-mcp-tool-search). To load every tool upfront instead, set `ENABLE_TOOL_SEARCH=false` in your shell or your [settings `env`](https://code.claude.com/docs/en/settings-reference#env). Before v2.1.304, tool search was off behind a gateway unless `ENABLE_TOOL_SEARCH` was `true`, `auto`, or `auto:N`.
1825When `ANTHROPIC_BASE_URL` points to a gateway, Claude Code expects the gateway to forward `defer_loading` tool fields and `tool_reference` blocks [along with the `anthropic-beta` header](https://code.claude.com/docs/en/llm-gateway-protocol#beta-header-and-body-field-pairs). Tool search is on by default behind the gateway, so MCP tools are [deferred](#scale-with-mcp-tool-search) and requests include those fields and blocks. Before v2.1.304, tool search was off behind a gateway unless `ENABLE_TOOL_SEARCH` was `true`, `auto`, or `auto:N`.
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1827On v2.1.305 or later, Claude Code can [retry a request without tool search](https://code.claude.com/docs/en/llm-gateway-protocol.md#retry-without-tool-search) after a `400` or `422` whose cause it doesn't recognize. When the retry works, nothing shows on screen and you don't need to do anything: MCP tools load upfront instead. Claude Code tries tool search again later, at the cost of another rejected request. To skip those requests, set `ENABLE_TOOL_SEARCH=false`.
1827On v2.1.305 or later, Claude Code can [retry a request without tool search](https://code.claude.com/docs/en/llm-gateway-protocol.md#retry-without-tool-search) after a `400` or `422` whose cause it doesn't recognize. When the retry works, nothing shows on screen and you don't need to do anything: MCP tools load upfront instead. Claude Code tries tool search again later, at the cost of another rejected request.
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18291829#### Tools that stay deferred below the `ENABLE_TOOL_SEARCH=auto` threshold
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