Claude Code can now download files with two new tools, FetchAttachment and DownloadTaskFile. Self-hosted runners get --hold-idle-file and --max-hold-min, which keep a session held while a file you update stays recent. Apps that embed Claude Code can pass a separate sign-in token for cloud sessions with CLAUDE_CODE_SESSIONS_OAUTH_TOKEN. Organizations can now list fingerprints of approved plugin releases in managed settings. A hooks plugin then loads only from a folder that matches one of them. Setting CLAUDE_CODE_PLAIN_DELTA_FAST_PATH turns on a quicker way to pass along plain streamed text when Claude Code runs without its interactive screen.
Some work in this build is not switched on yet. A built-in plugin that connects Claude to the Claude Platform developer docs is bundled but stays off. Background memory extraction can be made to run as a task you can stop, but this is off by default. Claude Code can also combine held-back pieces of a streamed reply into one update, and that is off unless switched on remotely. Several new server-controlled switches appear too, and what they control is not known.
Agent worktrees are no longer removed while another task is still working inside them. Attachments too big to hold in memory are now saved to the uploads folder instead of being rejected. Large images also get a smaller copy for Claude. Interrupting Claude Code while it reads an MCP resource or folder now cancels the read cleanly. Text with wide characters no longer overflows the terminal, because Claude Code now re-wraps such lines character by character. These are part of the fixes, and the full list is below.
Written by our agent from the shipped bundle, not by Anthropic.
Claude Code recognizes a --personal flag, and session start-up and cloud session creation gain persistentVolumeFromSessionId
InterfaceA new CLAUDE_CODE_EVEN_MORE_DANGEROUSLY_SKIP_PERMISSIONS variable appears, and some permission rules are now marked as not waivable in bypass mode
Remote sessions gain handlers that place downloaded files in a session folder, and plugins can paint text and decorations into the prompt box
ExtensionsNew environment variable CLAUDE_CODE_PLAIN_DELTA_FAST_PATH turns on a shortcut for streamed output in headless sessions
Managed settings can list pluginDigests on a marketplace, so plugins in prependPlugins or appendPlugins run at the organization tier
mcpMount settings layer and remembered security warningsSettings & configWant the reasoning? Read walks the 50 entries that probably matter to you, each one opening to what changed and why.
Read this release → Every row →6 more of these are in What probably matters to you, on page 1.
A server-controlled switch now goes by a different name; if the server sends nothing it still counts as on
Empty files are now read as empty text, and a new post-turn memory background task type and notice counter appear
Unclear It is not clear whether the new post-turn memory tasks are ever started or what they do.
Claude Code's list of sources now includes a label for memory gathered after a turn
Messages waiting in the queue, and messages from polling, now carry a record of the tools that were used
Unclear When this record is included, and what it changes for a reader, is not stated.
When an attempt to re-run a cut-off turn stands down, the messages it had queued are now cancelled
When Claude Code clears its mutual TLS cache, it now runs a cleanup step on each cached connection handler before forgetting it
A download that fails for being too large no longer always counts the same way; Claude Code now runs an extra check first
Unclear It is not known what data is being fetched ahead of time.
When starting another program fails, Claude Code now logs the error's original message, with fixed fallback text when there is none
One of Claude Code's command runners now keeps a command's error output instead of dropping it
The prompt box can now carry several named layers of highlighting, so different features can decorate what you type without clashing
A display option now accepts backgroundColor only as a theme colour name, a raw colour or "transparent"
Unclear Where a reader would set this option is not stated.
Published verbatim by Anthropic for v2.1.311. Text is unmodified from the upstream changelog. Everything else on this page came out of the bundle instead, which is why the two lists don't match.
Of these 92 bullets, 18 name something an entry on this page also names, 22 name something no entry here does, and 52 name nothing specific enough to line up either way. The pairings are made on names both sides wrote down, a flag or a setting or a slash command, so read one as probably the same thing rather than as a fact, and read the middle number as candidates rather than as a miss count.
--hold-idle-file and --max-hold-min to self-hosted-runner, to keep an idle session while your host reports processes it left running
Probably self-hosted-runner-holds-idle-release-while-a-left-running-p, self-hosted-runner-logs-a-leftover-hold-line-in-its-watchdog, self-hosted-runner-can-hold-sessions-while-a-host-file-stays claude -p and SDK sessions saving transcript messages out of order or keeping messages that were taken back
No entry names this SubagentStop hooks running about twice a minute for each running subagent instead of once when it finishes
No entry names this .ignore/.rgignore negation rules that re-include git-ignored files
Nothing to match on claude mcp add, claude mcp remove and /mcp naming the current folder instead of the project entry in ~/.claude.json that holds a local-scope server when run below a repository root
Probably mcp-clear-authentication-verifies-the-clear-and-reconnects, slack-mcp-server-gets-a-channel-posting-instruction, claude-api-skill-moved-into-a-plugin-gated-by-tengu-peppy-cr, new-bundled-plugin-cc-plugin-claude-platform-registered-in-t claude mcp list and claude mcp get showing the error code twice on failed-connection lines (for example ENOENT: ENOENT: …)
No entry names this claude daemon restart; it now suggests claude daemon stop --any and says it ends background sessions
No entry names this claude respawn <id> starting the background service before reporting that no background session matches the id
No entry names this /effort not warning about a prompt cache miss in plan mode when the plan model differs from the session model
Probably effort-line-can-say-it-may-wait-for-your-next-message, effort-step-keybinding-with-cache-miss-confirmation, shiftupdown-bound-to-effort-increasedecrease-in-chat-keyb /ide saying the VS Code extension was installed before the install finished or when it failed
Probably ide-extension-install-flow-and-prompt-footer-spacing, ide-installs-the-extension-with-progress-ui agent; Cowork cloud sessions now ignore that setting
Nothing to match on --resume, --continue, /resume or --session-id, including after /clear or a crash, and /branch writing to the original session's list
Probably team-lead-process-recorded-clear-keeps-task-list-link, resume-restores-prompt-waits ! open /tmp/shot.png or /review look at /tmp/shot.png, attaching the image and dropping its path from the prompt
Probably review-ultra-help-text-clarified #101693Option to disable automatic conversion of image file paths into [Image #N] attachments in the prompt input Open
"\" or (\), disappearing from Claude's responses
No entry names this DISABLE_COMPACT is set
Probably disable-compact-env-var-now-treated-specially-by-the-setting, disable-compact-now-also-stops-teammate-in-process-auto-comp DISABLE_COMPACT is set
Probably disable-compact-env-var-now-treated-specially-by-the-setting, disable-compact-now-also-stops-teammate-in-process-auto-comp /code-review, or another skill that runs in a sub-agent, running a second time when a cloud or background session restarts
Probably review-ultra-help-text-clarified /ide saying it had installed the JetBrains plugin when nothing was installed
Probably ide-extension-install-flow-and-prompt-footer-spacing, ide-installs-the-extension-with-progress-ui /mcp showing a remote server as failed after "Clear authentication" when the server works without sign-in
Probably mcp-clear-authentication-verifies-the-clear-and-reconnects, slack-mcp-server-gets-a-channel-posting-instruction, claude-api-skill-moved-into-a-plugin-gated-by-tengu-peppy-cr, new-bundled-plugin-cc-plugin-claude-platform-registered-in-t /mcp showing "authenticated" for a remote server that Claude Code sends no credentials to
Probably mcp-clear-authentication-verifies-the-clear-and-reconnects, slack-mcp-server-gets-a-channel-posting-instruction, claude-api-skill-moved-into-a-plugin-gated-by-tengu-peppy-cr, new-bundled-plugin-cc-plugin-claude-platform-registered-in-t #98942[BUG] Claude Code marks an anonymous MCP server authenticated when it lists a tool Open
--plugin-dir folder of plugins loading as one plugin when an empty .mcp.json was at its top
Probably empty-mcpjson-is-skipped-claudemd-files-naming-devices-a /usage never showing large prompt-cache misses under "What's contributing to your limits usage?"
No entry names this CLAUDE_CODE_RETRY_WATCHDOG), indefinitely
No entry names this bwrap: Can't create file when a --plugin-dir folder was also an added directory and permissions.blockReadsOutsideWorkingDirectories was on
No entry names this /teleport and claude --teleport to warn when a compacted cloud session loads from its last compaction, so the messages it summarized aren't in the local copy
No entry names this #name and no longer says the address bar stays the same as you switch views
Nothing to match on claude --model opus
No entry names this ultrathink in the interactive terminal to run its turn at xhigh effort on Opus 5.5, Sonnet 5.5, Haiku 5.5 and Fable 5.1 through Anthropic's API; typed while Claude is working, it raises the rest of that turn
Nothing to match on ultrathink rainbow to appear only where the keyword can raise effort, and not when the word is quoted or part of a file path
Nothing to match on --output-format json and stream-json output to write DEL, C1 control and Unicode format characters inside strings as \uXXXX escapes; parsed values are unchanged
No entry names this [1m] suffix and its label on models where the suffix has no effect; the suffix is still accepted
Probably model-name-resolution-no-longer-special-cases-the-1m-suffix /code-review to tell Claude to put the effort level first and use max only when asked
Probably review-ultra-help-text-clarified DISABLE_COMPACT in settings files and in a mod's $.env.set so they can only turn compaction off, not back on
Probably disable-compact-env-var-now-treated-specially-by-the-setting, disable-compact-now-also-stops-teammate-in-process-auto-comp CLAUDE_CODE_SYNC_SKILLS with feature-flag fetching off to reuse a claude.ai skills list up to 10 minutes old that another session on the machine fetched
No entry names this claude purge to say it deletes data only on this computer, not anything stored by Anthropic
No entry names this DISABLE_TELEMETRY set while VS Code's telemetry setting is off, so they send no usage metrics or error reports and fetch no feature flags
No entry names this A model matched these bullets to the GitHub issues they fix, so a link can be wrong.
1 of 30 tool descriptions changed. The appended system-reminder blocks moved: 4 lines added, 5 lines removed.
Claude Code, interactive mode
12 prompt changes in this release could not be quoted from the build, so no entry on this page describes them.
437 documentation changes were recorded within 24 hours either side of this release, nearest first. The closest 12 are below. They're here because they happened near this release in time. That's not a claim that this release caused the edit, or that the page documents anything in it.
The 79 literal strings found in the bundle, with the number of entries that name each one. Picking one searches for it. A name is here because this build's code mentions it, which is not the same as it working or being finished.
What's wrong with this entry?