Week 36 · August 31 – September 4, 2026 changedwhats-new/2026-w36
Nearest release: v2.1.272, published an hour before 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 15 Sep 2026 00:38 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 22 Oct 2026 18:07 UTC.
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33> Switch to Claude Fable 5.1, let computer use run in the background on Desktop, and watch Claude's edits in a live /diff panel.
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5Releases [v2.1.251 → v2.1.261](/docs/en/changelog#2-1-251)
5Releases [v2.1.251 → v2.1.261](/docs/en/changelog.md#2-1-251)
664 features · August 31 – September 4
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88Claude Fable 5.1
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1919On the Anthropic API, the picker lists Fable only once the server reports it available for your organization, but typing `/model fable` checks with the server directly.
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21[Work with Fable](/docs/en/model-config#work-with-fable)
21[Work with Fable](/docs/en/model-config.md#work-with-fable)
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2323Computer use runs in the background on Desktop
2424Desktop
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30[Let Claude use your computer](/docs/en/desktop#let-claude-use-your-computer)
30[Let Claude use your computer](/docs/en/desktop.md#let-claude-use-your-computer)
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3232Live diff panel in fullscreen rendering
3333v2.1.260
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4545Run `/diff` again or click the `✕` in its header to close it.
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47[Diff panel](/docs/en/interactive-mode#diff-panel)
47[Diff panel](/docs/en/interactive-mode.md#diff-panel)
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4949Find unused skills with /skill-doctor
5050CLI
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52`/skill-doctor` shows what each of your skills costs in context and how often it gets used, so you can decide which ones to turn off. Every skill in the [skill listing](/docs/en/skills#skill-descriptions-are-cut-short) adds to your context on every turn, whether or not Claude ever uses it. Requires v2.1.252 or later and isn't available in sessions that skip [feature-flag fetching](/docs/en/env-vars#features-that-need-feature-flag-fetching).
52`/skill-doctor` shows what each of your skills costs in context and how often it gets used, so you can decide which ones to turn off. Every skill in the [skill listing](/docs/en/skills.md#skill-descriptions-are-cut-short) adds to your context on every turn, whether or not Claude ever uses it. Requires v2.1.252 or later and isn't available in sessions that skip [feature-flag fetching](/docs/en/env-vars.md#features-that-need-feature-flag-fetching).
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5454Run it in an interactive session to open the report in the `/plugin` manager's **Stats** tab:
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6060In non-interactive mode with `-p`, Claude Code prints the report as text instead.
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62[Find unused skills](/docs/en/skills#find-unused-skills)
62[Find unused skills](/docs/en/skills.md#find-unused-skills)
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6464Other wins
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66A [`PreModelSwitch`](/docs/en/hooks#premodelswitch) hook can block a model switch you request, and a [`PostModelSwitch`](/docs/en/hooks#postmodelswitch) hook can add context for Claude after the session's model changes[`/cost`](/docs/en/costs#prompt-cache-statistics) adds a `Prompt cache (main)` line: the share of input tokens served from cache, the cache misses, whether the cache is warm, and a likely cause for the last miss when Claude Code can name one. Status line scripts get a matching `prompt_cache` objectOrganizations can list HTTP and SSE MCP servers under the [`managedMcpServers`](/docs/en/managed-mcp#provide-servers-through-managed-settings) managed setting to give them to every user, in addition to the servers that users add on their own`/effort` and the `/model` picker now [save a separate effort level for each model](/docs/en/model-config#adjust-effort-level); press `s` instead of `Enter` to apply a level to the current session onlyBy default, the auto mode classifier [now also blocks](/docs/en/permission-modes#what-the-classifier-blocks-by-default) actions such as requesting credentials from the cloud instance-metadata endpoint or connecting to sibling containers that Claude didn't startIn auto mode, Claude Code asks you before Claude [first reads a file outside your working directories](/docs/en/permission-modes#first-read-outside-the-working-directories), with an option to block such reads from then onRaise [`bashOutputMaxChars`](/docs/en/settings-reference#bashoutputmaxchars) and [`taskOutputMaxChars`](/docs/en/settings-reference#taskoutputmaxchars), up to 128,000 characters, so Claude receives more of the output from a successful command or background task inlineThe prompt's [word-editing shortcuts follow readline](/docs/en/interactive-mode#make-ctrl-w-delete-back-to-whitespace) for everyone, and the `keybindingFlavor` setting no longer has any effect. `Ctrl+W` deletes back to the previous whitespace, and `Alt+B`, `Alt+F`, and `Alt+D` treat punctuation such as `/` and `.` as word breaksIf you set `defaultMode` to `"bypassPermissions"` in a project's `.claude/settings.json` or `.claude/settings.local.json`, it [no longer takes effect](/docs/en/permission-modes#which-mode-a-session-starts-in) and the session starts in Manual mode; set `"bypassPermissions"` in user or managed settings instead, or pass `--permission-mode`Seat-based Enterprise plans now [default to Opus 5](/docs/en/model-config#default-model-setting)In the VS Code extension, click the model name at the bottom of the prompt box to [open the model picker](/docs/en/vs-code#use-the-prompt-box)In the VS Code extension, select **Output styles** in the command menu's Customize section to [pick an output style](/docs/en/vs-code#use-the-prompt-box), including your custom ones
66A [`PreModelSwitch`](/docs/en/hooks#premodelswitch) hook can block a model switch you request, and a [`PostModelSwitch`](/docs/en/hooks#postmodelswitch) hook can add context for Claude after the session's model changes[`/cost`](/docs/en/costs#prompt-cache-statistics) adds a `Prompt cache (main)` line: the share of input tokens served from cache, the cache misses, whether the cache is warm, and a likely cause for the last miss when Claude Code can name one. Status line scripts get a matching `prompt_cache` objectOrganizations can list HTTP and SSE MCP servers under the [`managedMcpServers`](/docs/en/managed-mcp#provide-servers-through-managed-settings) managed setting to give them to every user, in addition to the servers that users add on their own`/effort` and the `/model` picker now [save a separate effort level for each model](/docs/en/model-config.md#adjust-effort-level); press `s` instead of `Enter` to apply a level to the current session onlyBy default, the auto mode classifier [now also blocks](/docs/en/permission-modes.md#what-the-classifier-blocks-by-default) actions such as requesting credentials from the cloud instance-metadata endpoint or connecting to sibling containers that Claude didn't startIn auto mode, Claude Code asks you before Claude [first reads a file outside your working directories](/docs/en/permission-modes.md#first-read-outside-the-working-directories), with an option to block such reads from then onRaise [`bashOutputMaxChars`](/docs/en/settings-reference#bashoutputmaxchars) and [`taskOutputMaxChars`](/docs/en/settings-reference#taskoutputmaxchars), up to 128,000 characters, so Claude receives more of the output from a successful command or background task inlineThe prompt's [word-editing shortcuts follow readline](/docs/en/interactive-mode.md#make-ctrl-w-delete-back-to-whitespace) for everyone, and the `keybindingFlavor` setting no longer has any effect. `Ctrl+W` deletes back to the previous whitespace, and `Alt+B`, `Alt+F`, and `Alt+D` treat punctuation such as `/` and `.` as word breaksIf you set `defaultMode` to `"bypassPermissions"` in a project's `.claude/settings.json` or `.claude/settings.local.json`, it [no longer takes effect](/docs/en/permission-modes.md#which-mode-a-session-starts-in) and the session starts in Manual mode; set `"bypassPermissions"` in user or managed settings instead, or pass `--permission-mode`Seat-based Enterprise plans now [default to Opus 5](/docs/en/model-config.md#default-model-setting)In the VS Code extension, click the model name at the bottom of the prompt box to [open the model picker](/docs/en/vs-code.md#use-the-prompt-box)In the VS Code extension, select **Output styles** in the command menu's Customize section to [pick an output style](/docs/en/vs-code.md#use-the-prompt-box), including your custom ones
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68[Full changelog for v2.1.251–v2.1.261 →](/docs/en/changelog#2-1-251)
68[Full changelog for v2.1.251–v2.1.261 →](/docs/en/changelog.md#2-1-251)
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