## 2.1.251

- Added `PreModelSwitch` and `PostModelSwitch` hook events (block, confirm, or annotate a model switch); `SessionStart` resume hooks now receive session staleness and the estimated re-cache cost
- Added live streaming of a foreground subagent's tool calls and results to Remote Control clients (background subagents, the default, still show status only)
- Added a Spend limit bar to `/usage` and a `rate_limits.spend_limit` status line field for developers behind a Claude apps gateway with spend limits
- Added a per-session prompt-cache line to `/cost` (hit ratio, misses, tokens re-cached, warm/cold) and a matching `prompt_cache` object for status line scripts
- Added `attach`, `logs`, `stop`, `respawn`, and `rm` to `claude --help`; the `--resume` message for a running background session now names the exact `claude attach <id>` command
- Fixed file tools (Read, Write, Edit) following a symlink swapped inside the working directory after the permission check, which could read or write outside the approved location
- Fixed plugin commands declared in a marketplace entry being able to point outside the plugin directory; such paths are now rejected with a path-traversal error
- Fixed project settings being able to enable detailed beta tracing or raw API body logging, and a lower-scope beta tracing endpoint bypassing an OTLP collector pinned by managed settings or a host app
- Fixed the Workflow tool reading (and quoting in errors) a `scriptPath` outside what the session may read before the permission check ran
- Fixed Grep and Glob not applying `Read(...)` deny rules to files reached through a symlinked search path
- Fixed conversations getting stuck on "text content blocks must be non-empty" errors after a turn where the model produced only thinking
- Fixed the first launch on a fresh install starting in default mode instead of auto mode for accounts whose startup default is auto mode
- Fixed Opus 5 requests failing with "effort … is not supported when thinking is disabled" when effort was xhigh/max and thinking was turned off; effort is now sent as `high` in that case
- Fixed replying to a message Claude Desktop delivered from another session: `SendMessage` to that session id now delivers through Claude Desktop instead of failing with "not reachable"
- Fixed TUI lag with many parallel subagents: per-second progress ticks now replace their predecessor instead of piling up in the transcript
- Fixed agent teams: a teammate's final answer not reaching the team lead — it now arrives in the idle notification instead of a content-free "available" notice
- Fixed background subagents being unable to reply to a message from an unnamed sibling or parent agent (`from` was the agent type, which is not an address)
- Fixed managed-settings `disableAutoMode` arriving mid-session not moving an already-running auto-mode session back to default mode
- Fixed a "switch to Opus 1M for 5x more context" tip that appeared even when the current Opus model already has a 1M context window
- Fixed Claude apps gateway sessions treating a stored Anthropic profile (e.g. a Console sign-in) as active: listing it in `/status` and retrying gateway 401s with it, though requests never use it
- Fixed cloud sessions telling Claude the model had changed when the host was only setting the session's initial model
- Fixed Remote Control reporting a failure when an organization's policy disables it; it now shows a single quiet notice instead
- Fixed `/mcp reconnect` on Remote Control showing a generic withheld-detail error instead of the real remedy when a server was disabled in another session
- Fixed `--input-format stream-json`: client-injected assistant tool calls sent without a message id were merged into the first one and their results lost, including when resuming older sessions
- Fixed session transcripts being silently overwritten when a directory change relocated a session onto an existing same-ID transcript
- Fixed background sessions and their subagents being unable to edit files inside a git worktree they created with `git worktree add`
- Fixed background sessions occasionally starting without any plugin skills (and staying that way) when another Claude Code process was refreshing the plugin marketplace at the same moment
- Fixed selecting text in an opened background session inside tmux over SSH: it now copies to the tmux buffer like a foreground session instead of falling back to OSC 52
- Fixed SDK and cloud sessions hanging indefinitely when an SDK MCP server's handshake acknowledgment was lost; the wait now times out after 70 seconds and marks only that server failed
- Fixed self-hosted runner leaving a stuck session's Bash tool processes running after the session was force-stopped
- Fixed `/usage-credits` for Team and Enterprise members whose admin set the org's usage-credit limit to $0: it now offers to ask the admin instead of saying a cap was reached
- Fixed `--worktree --tmux` with a merge-request number on a gitlab.com origin trying a doomed GitHub-style fetch first instead of fetching the GitLab ref directly
- Fixed Ctrl+G failing with "Emacs quit unexpectedly" in background sessions for editors that open `/dev/tty`, such as `emacs -nw` and `micro`
- Fixed an `additionalDirectories` entry containing a null byte crashing startup, or breaking `/add-dir` and later settings updates when it came from an SDK host, IDE, or hook; it is now skipped
- Fixed the MCP server menu's copy shortcut: it now says how the sign-in URL was copied instead of always claiming success
- Fixed italic text (such as the session recap line) rendering as highlighted blocks in GNU screen and in tmux sessions using a `screen` terminal type
- Fixed `claude mcp add --header` and `claude mcp add-json` help text naming the wrong transports
- Fixed `claude ultrareview` and `/ultrareview` waiting the full 30 minutes when the cloud session fails to start; they now stop early and report the reason
- Fixed Bash permission checks auto-approving commands that assign an arithmetic expression to an integer shell variable (e.g. `OPTIND=1/0`, `RANDOM=2+2`); these now prompt for approval
- Fixed backgrounded sessions (`←`, `/background`, `--bg`) losing a Vertex/Bedrock gateway (`ANTHROPIC_*_BASE_URL` + `CLAUDE_CODE_SKIP_*_AUTH`) exported in the shell, so every request failed
- Fixed `claude --bg --model fable` on Max plans stopping to ask for usage credits while the interactive session on the same account still had Fable allowance
- Fixed the one-time "make auto mode your default" offer appearing in unattended sessions (e.g. agent-team teammate panes), where a stray keypress could accept it unread
- Fixed the managed-settings approval prompt re-appearing after signing in again to the same Claude apps gateway when the settings are unchanged
- Fixed disabled `/bug` and `/share` reporting that `/feedback` was disabled; tips, `/help`, and refusal messages no longer suggest `/feedback` when an org policy or env var turns it off
- Fixed cloud session creation advising GitHub setup after a transient GitHub connection failure — the message now says to retry instead
- Improved CPU usage during turns in interactive sessions by cutting redundant UI re-renders
- Improved install size: the native binary is about 5 MB smaller
- Improved cloud sessions: when the session's network proxy drops a connection during a Bash command, the tool result now names the host and reason instead of only "connection reset"
- Improved `/schedule` to explain that MCP servers configured in Claude Code can't be attached to cloud routines, instead of a bare "No MCP connectors" message
- Improved framing of messages from your own subagents: Claude is told the sender is a worker inside this session, not an unrelated Claude session
- Improved the prompt placeholder to read "Message @name…" while viewing a background subagent or fork transcript opened from the subagent panel or `/tasks`
- Improved sanitization of MCP server names in error messages, menus, and command results
- Improved Amazon Bedrock session start under `CLAUDE_CODE_PROVIDER_MANAGED_BY_HOST` (e.g. Claude Desktop): a session given a Bedrock model ID or ARN no longer waits for inference-profile discovery
- Improved the managed settings approval dialog to list only the settings that changed since you last approved them
- Improved retry when the model's tool call is malformed: the broken output is now dropped from the retry context, including on Bedrock, Vertex, and Foundry
- Changed `/radio` to be available on Bedrock, Vertex AI, Foundry, and Claude Platform on AWS, and when telemetry is disabled
- Changed Claude in Chrome so browser actions always go through Claude Code's permission checks, including in sessions with telemetry disabled, which previously used the Chrome extension's own prompts
- Changed `CLAUDE_CODE_SUBAGENT_MODEL` to set the default subagent model rather than override everything: an agent definition's `model:` and an explicit per-spawn model now take precedence over it
- Changed the default commit trailer to `Co-Authored-By: Claude Code` when the active model isn't a recognized Claude model (e.g. third-party models behind a custom `ANTHROPIC_BASE_URL`)
- Changed the default model for seat-based Enterprise subscriptions to Opus 5, matching other premium plans
- Changed `/effort` to save your default effort level per model, so each model keeps its own setting when you switch
- Changed analytics to no longer turn off before sign-in solely because managed settings force gateway login (or cannot be read); they stay off once signed in to the gateway or via `DISABLE_TELEMETRY`
- Changed the footer PR badge on Bedrock, Vertex, and Foundry, and when telemetry is off, to call the GitHub API directly (via `gh auth token`, `GH_TOKEN`, or `GITHUB_TOKEN`) instead of `gh pr view`
- Changed how Bash command output files are created and read back when commands run in the sandbox, so a sandboxed command cannot redirect or replace them
- Changed plugin/LSP install suggestions and the auto-mode default offer to wait until you've sent or cleared what you're typing, so the Enter that sends your prompt can't answer them
- Changed server-managed settings that terminate sandbox TLS, route sandbox traffic through your own proxy, inject credentials, or weaken sandbox isolation to require approval before they apply
- Changed `ANTHROPIC_CUSTOM_HEADERS` from managed or project settings to require approval when it sets a credential, org/tenant, routing, or API-behavior header (e.g. `Authorization`, `Host`)
- Changed project-level `.claude/settings.json` `env` to no longer set `CLAUDE_CONFIG_DIR`, `CLAUDE_CODE_TMPDIR`, or `TMPDIR`/`TMP`/`TEMP`; set them in your shell, user, or managed settings instead
- Removed syntax highlighting for six rarely used languages (1c, gml, isbl, mathematica, maxima, sqf); the binary is 2.5 MB smaller
- [VSCode] Fixed the sign-in screen's "Bedrock, Foundry, or Vertex" button opening the docs at the top of the page instead of the third-party provider setup section
- [VSCode] Changed the Remote Control banner to a footer pill (shown while Remote Control is on or has failed) that opens the session on claude.ai/code; turn it on or off with `/remote-control`