Claude Code 2.1.283

September 25, 2026

This release introduces new features for auditing your prompts against older model patterns and for precisely controlling available models, including the ability to block specific versions. Significant improvements enhance core platform stability, plugin management, and UI responsiveness, making interactions more reliable and efficient. Users will experience better handling of tool calls, faster startup times, and smoother navigation across various lists. This update also provides crucial fixes for cloud sessions, Code Review, and Slack integration, ensuring a more robust and predictable experience for all workflows.

Added

Added `x-claude-code-prompt-id` to the gateway hint headers so LLM gateways can group the requests that serve one user prompt; opt in with `CLAUDE_CODE_GATEWAY_HINT_HEADERS=1`
Added `availableModelsMatch` managed setting: with `"exact"`, an `availableModels` entry allows only the model version it names, so new releases stay blocked until listed
Added `deniedModels` managed setting to block specific models, even when `availableModels` allows them
Added MCP tool, WebFetch and WebSearch outputs to the `tool.output` OpenTelemetry span event when `OTEL_LOG_TOOL_CONTENT=1`
Added `/doctor prompt-audit` (also `/checkup prompt-audit`) to audit your CLAUDE.md files, skills, agents and commands for prompting patterns written for older models
Added click-to-expand for truncated messages from your other sessions in fullscreen mode
Added `path` to `--plugin-dir` load-failure entries in the stream-json `system/init` `plugin_errors`, naming the directory that did not load
Added an opt-in `load_test_mode` block to the Claude apps gateway config: requests are built and signed but not sent upstream, and clients get a canned reply, so a deployment can be load tested
Added a `mantle` upstream provider to the Claude apps gateway for Amazon Bedrock's Mantle endpoint

Improved

Improved the `/mcp` tool list: it shows more tools at once, scrolls with the page keys and mouse, and marks tools your organization blocked with a warning icon
Improved MCP tool results: images returned by MCP tools are now also saved to a file, so Bash, Read and other tools can open them
Improved `/tasks`: rows show a status icon, the name and whole facts, the title and key hints stay on screen with many tasks, and the list gains paging keys, the mouse wheel and clicks
Improved lists in `/help`, `/hooks`, `/copy`, `/chrome`, `/memory`, `/ide`, `/release-notes`, `/rewind`, `/diff`, `/remote-env`, `/plugin` and other pickers with page keys, mouse wheel and clicks
Improved lists beside a search box, such as `/skills` and `/artifacts`, to draw their pointer dim while the search box has the keys, so only one pointer is highlighted
Improved the compaction spinner: its timer now starts when compaction begins and it counts the summary's tokens as they stream, replacing the percentage bar
Improved the browser page shown after signing in to an MCP server: centered layout, dark mode, and new artwork
Improved the Skill tool's reply when a skill belongs to a plugin that failed to load, so Claude tells you the plugin could not be loaded instead of calling the skill uninstalled
Improved `prompt-audit` on Claude Code configuration: stale paths, stale commands and contradicting instruction files now lead the report, and thinking keywords that Claude Code documents are kept
Improved recovery from an `installed_plugins.json` that cannot be read at all: its contents are kept in a file beside it before it is rebuilt, and `claude plugin list` names that file
Improved artifact database reads: an ordered query that returns a full page now says it is one page and how to read the rest
Improved first-reply latency: a pattern-compile step that ran at the end of a session's first reply now runs while the reply streams in
Improved first-request latency by reusing the preconnected API connection
Improved startup: `claude -p` and Claude Code Remote no longer load the interactive UI, and the auto-mode classifier's rules and the Artifact tool load on first use instead of at launch
Improved startup for claude.ai accounts whose Artifact tool features aren't known yet, as on a first run: the prompt no longer waits up to 1.5 s to check them; the first message waits if needed

Changed

Changed interactive sessions on third-party providers or with telemetry off to start in auto mode when no permission mode is configured; `permissions.defaultMode` still overrides it
Changed the `/ultrareview` launch dialog to say that reviewing a local branch may upload uncommitted changes to tracked files
Changed the `/model` picker's Opus row and the Default model's name to drop "(1M context)" where Opus already has a 1M context window; the window is unchanged
Changed prompt suggestions in the terminal to appear less often after 20 in a row go unused; using one brings them back
Changed `--system-prompt` and `--append-system-prompt` to accept their text and `-file` forms together; the file's text comes first
Changed `Skill(anthropic-skills:<name>)` deny rules to also block that skill when Claude Desktop delivers it as a plugin, and `Skill(skill:<name>)` denies to match the skill's alias and display name
Changed `/rewind` and `/diff` lists to move on the same keybinding actions as every other list (`select:*`); `messageSelector:*`/`diff:*` rebinds still work
Changed the `/workflows` run list to size itself like other lists: half the terminal inline, and it keeps its title on screen when the prompt shows below
Changed `claude plugin eval` to require git 2.31 or later when git is installed; a run on an older git is refused with a message naming the version
Changed artifact watching: a watch that was armed automatically (not one you asked for) now ends after 3.5 hours with no activity; publishing or watching the artifact again re-arms it
Self-hosted runner: Changed lifecycle hooks' git to skip a repository's Git LFS `pre-push` hook, ignore a writable system `core.hooksPath`, and not sign commits without `--configure-git`
Self-hosted runner: Changed `GIT_SSL_CAINFO` and `GIT_SSL_NO_VERIFY` under Anthropic-managed git: the runner's own git always verifies Anthropic's git route, and warning lines say what applies where
Reverted the 2.1.282 reservation of the `claude-ai` name: skills, commands, workflows and MCP servers' skills and prompts so named load again, and `Skill(claude-ai:*)` rules are ordinary prefix rules
[Cloud sessions] Improved adding a repository to a running cloud session: a private repository your GitHub account can read but not push to now attaches for reading
[Cloud sessions] Changed new routine schedules to default to a few minutes past the hour, with a note that routines set exactly on the hour can start several minutes late
[Claude Tag] Added a "Channels Claude can search" admin setting that limits Claude's Slack search to public channels it has been added to, set per organization, workspace or channel
[Claude Tag] Added a Back to Slack button on the page shown after connecting your Claude account, returning you to the thread you started from

Fixed

Fixed SDK sessions losing a deferred tool call or finished tool result when a turn ended early, a held approval prompt after a worker restart, and a non-streaming fallback's `result.usage`
Fixed MCP progress notifications being discarded once a long-running tool call moved to the background; the background task now shows the latest progress
Fixed stdio MCP servers being left running when the session ended while they were still starting
Fixed a brief HTTP 404 from a stateless remote MCP server (for example a proxy mid-redeploy) leaving that server unusable for the rest of the session while still shown as connected
Fixed MCP sign-in for a server with no valid URL failing with an opaque SDK error; `/mcp` no longer offers Authenticate for such servers
Fixed the weekly Fable limit not appearing in `/usage` and the VS Code usage meters when telemetry is disabled
Fixed `/model` accepting Sonnet 4.6 or Sonnet 5 with `[1m]` when the id carried a date or `-v1:0` suffix, in the cases where the plain id was refused
Fixed `/model` picker showing a hardcoded Haiku version and price when `ANTHROPIC_DEFAULT_HAIKU_MODEL` pins a different model
Fixed dynamic workflows started during a model fallback running every agent on the fallback model instead of retrying the configured model
Fixed `DISABLE_PROMPT_CACHING_HAIKU` having no effect when Haiku is the session's main model
Fixed `claude plugin validate` saying Claude Code accepts a plugin or marketplace name it cannot install; such names in `marketplace.json` now fail validation
Fixed `claude plugin validate` passing plugins whose `outputStyles`, `themes`, `monitors`, or `lspServers` paths are missing or point outside the plugin directory
Fixed `claude plugin details` showing 0 MCP servers for plugins that declare their servers in `plugin.json`
Fixed `claude plugin marketplace remove` not saying which installed plugins it uninstalled with the marketplace; it now lists them
Fixed `claude plugin uninstall` removing the other of two installed plugins whose ids differ only in case, with its options and secrets, when the one named had no `enabledPlugins` entry at that scope
Fixed plugins that declare no version being silently restored at their source's newest commit, not the installed one, when their cached files were missing
Fixed user-installed plugins and marketplaces failing to load with "cache-miss" after the home or config directory was moved, for example in bind-mounted devcontainers
Fixed `installed_plugins.json` showing no plugins when it holds a record under an invalid plugin id; such a file loads again
Fixed `installed_plugins.json` being rewritten, losing records, when it holds a record this version cannot read; `claude plugin` commands now name the record and say how to recover
Fixed permission dialogs in screen-reader mode reading quoted commands and paths as if they were the dialog's own text
Fixed `/context` not counting MCP server instructions: they now appear as their own row and count toward the total
Fixed markdown links in the Warp terminal rendering as plain text instead of clickable hyperlinks
Fixed `claude mcp add`, `add-json`, and `remove` reporting success when the user or local config file could not be written, for example inside a sandbox
Fixed the first words of a reply in a cloud session sometimes appearing late instead of streaming as Claude writes them
Fixed Claude's built-in keybindings guide saying chords time out after 1 second instead of 3, and calling `cmd` an alias of `meta`, which could produce `cmd+` shortcuts most terminals never send
Fixed `keybindings.json` silently accepting a misspelled modifier such as `ctl+k`; it now warns in the debug log and suggests the fix
Fixed footer hints still saying "Enter to view" after `footer:openSelected` was rebound or unbound in `keybindings.json`
Fixed keys typed quickly together (type-ahead, key repeat, bursts over ssh or tmux) sometimes being handled against stale state
Fixed worktree checkouts failing certificate verification (for example on Git LFS downloads) when the CA certificate is passed to git as `GIT_CONFIG_COUNT` environment pairs
Fixed sandboxed `git` asking credential helpers to store the sandbox proxy's login, which printed "failed to store"
Fixed managed `sandbox` settings being ignored entirely when one nested value was invalid; the invalid value now fails closed and the rest of the block still applies
Fixed Claude's edits to its own auto-memory notes being blocked as sensitive-file writes when Claude Code was started in a subdirectory of a git repository
Fixed Remote Control being unavailable on paid plans when telemetry is turned off with `DISABLE_TELEMETRY` or `DO_NOT_TRACK`
Fixed the `/remote-control` menu cutting its QR-code hint mid-word in narrow terminals
Fixed vim mode `.` dropping a Shift+Enter newline, leaving the cursor inside an accented letter, and repeating an older change after `3J` or Visual-mode `J` on the last line
Fixed vim mode cursor placement: recalling a prompt over 10,000 characters in normal mode no longer leaves the cursor past the end, and `V` then `p` now lands on the first non-blank
Fixed vim mode `J` joining lines with different spacing than Vim (such as a space before `)` or after a tab), and `3J` or Visual-mode `J` on the last line not moving the cursor as Vim does
Windows: Fixed the PowerShell tool letting `cmd /c rd`, `rmdir`, `del` or `erase` delete drive roots, the home folder and other folders that `Remove-Item` refuses
Fixed the permission mode indicator showing Default while the session kept running in auto or bypass mode after an automatic switch out of it failed; the switch is now retried until it lands
Fixed a session teleported from the web dropping the messages sent while Claude was working
Fixed a Web session staying hidden from the session list, and an empty chat opening in its place, when an older version had saved an empty local copy of it
Fixed a reopened session splitting a turn at a message Claude received mid-turn, such as an automatic continuation
Fixed a reloaded session showing a rewound-away turn, or only the rows before a compaction
Fixed the footer's agents pill drawing its icon off-center, with the status dot against the edge, in narrow panels
Fixed the chat input showing its text slightly below the cursor and selection after pasting lines that end with a line break into a long prompt
[Cloud sessions] Fixed cloud sessions occasionally redoing an already-finished step, such as posting a duplicate comment or push, after recovering from a server-side restart
[Claude Tag] Fixed a channel's configure page listing no connectors or plugins when the channel gets its access bundle through an attach rule; rule-attached bundles are now shown
[Claude Tag] Fixed access-bundle repository search missing repositories on GitHub App installs that are limited to a large list of selected repositories
[Claude Tag] Fixed Claude occasionally posting the same reply twice when a new message interrupted it mid-reply
[Claude Tag] Fixed channel routines that stopped running in older private channels whose Slack channel ID changed, for example after a Slack Connect share
[Claude Tag] Fixed conversations in a channel set to "Channel only" all ending when a non-guest member joined and Slack was slow to confirm their membership
[Code Review] Fixed "@claude review" requests going silent when GitHub failed to return the pull request: the request is retried once, and a comment explains if it still fails
[Code Review] Fixed billing for a review that stopped at its time limit with nothing verified: it now shows as incomplete, isn't charged, and is retried once