Agent Breaking Changes_

← Claude Code

Claude Code v2.1.299

deprecatedmodelpricing

2026-10-14 · official notes

Summary

Full notes

## What's changed

- Added `CLAUDE_CODE_DISABLE_FILE_MENTIONS` environment variable: Claude gets the paths of `@` file mentions to read with its file tools, not the files' contents
- Added idle compaction in the terminal: a 200K+ token conversation left idle for about 54 minutes is compacted before its one-hour prompt cache expires, so your next message doesn't reprocess it all
- Added `CLAUDE_CODE_IDLE_COMPACT_MIN_TOKENS` to change idle compaction's 200K-token minimum; `"idleCompaction": false` in settings.json turns it off. Both need v2.1.290 or later
- Added `$.prompt.media` so a `prompt.submit` hook of a mod installed by managed settings can read the bytes of an image or document attached to the prompt
- Added `$.session.identity()` for mods installed by managed settings: how the session is signed in, and its organization and email when managed `forceLoginOrgUUID` lists that organization
- Added `size`, `weight`, `mono` and `tabular` to a mod's `Text` and named spacing steps (`xs` to `xl`) to its `Box`; `bold` is deprecated in favor of `weight`
- Added `--shutdown-drain-sec` to `claude self-hosted-runner orchestrator`: on SIGTERM it stops polling and gives the poll in flight and running spawn hooks up to that many seconds to finish
- Added the skill's frontmatter, source, plugin name and file path to what a mod's `skill.prompt` hook receives
- Added `/effort` and `/fast` in agent view to set what new sessions start with; a bare `/model`, `/effort` or `/fast` there now opens a picker
- Added a "safe mode" line to the agents view peek panel for background sessions started with `--safe-mode`
- Added a one-time note when plan mode won't ask before most edits or commands because bypass permissions is available
- Added `--disallow-tools` and a `disallowed_tools` case field to `claude plugin eval` to keep specific built-in tools, such as Agent, out of eval runs
- Added support for turning off the attribution block in Claude Desktop's Code tab: set `CLAUDE_CODE_ATTRIBUTION_HEADER=0` in the `env` of a Claude apps gateway's `code` policy
- Added a field to the attribution block in Claude Code sessions behind a Claude apps gateway; remove the block with `CLAUDE_CODE_ATTRIBUTION_HEADER=0`
- Added a `queue` door to the `session.append` mod hook, so a mod can make the transcript's queue records differ from the prompt as sent
- Added a note in `/plugin` and `claude plugin validate` naming a mod's hooks that are skipped where an organization manages Claude Code
- Added `/usage` warnings for max effort, workflows, always-on context and large tool results
- Fixed the error for a denied cloud session, which could point to the wrong organization when a key from `apiKeyHelper` was in use
- Fixed sessions on a gateway-specific model name behind a custom `ANTHROPIC_BASE_URL` ending with "Prompt is too long · automatic compaction failed" near 200K tokens instead of sending the request
- Fixed a mod that submits a prompt at the end of every turn keeping a headless run going past `--max-turns`, `--max-budget-usd`, an interrupt, or the end of the host's conversation
- Fixed cloud sessions sometimes showing the model's follow-up text after a tool group's one-line label
- Fixed the Write and Edit tools creating a mod in a session's mods folder without asking in accept-edits mode when the config directory's path has no `.claude` in it
- Fixed installed mods that kept running in an open session after being turned off remotely; they now unload between turns
- Fixed Edit and Retry in Cowork and claude.ai cloud sessions failing on a message stopped while its `UserPromptSubmit` or mod `prompt.submit` hooks were still running (regression in 2.1.296)
- Fixed an agent teammate started without a description keeping part of a credential from its prompt in the task description shown for it
- Fixed the claude.ai view of a Remote Control or cloud session freezing when a large batch of events could not finish uploading over a slow connection
- Fixed a sandboxed shell command being able to write into a `--plugin-dir` folder, whose code Claude Code reloads and runs outside the sandbox
- Fixed memory growth under heavy debug logging (`--debug`, `--debug-file`), and a hang on exit when the debug log is on a disk or network mount that stops accepting writes
- Fixed memory growing without bound when debug output goes to stderr and the parent process stops reading it
- Fixed rm prompts on shell `-c` scripts that don't run `rm`. An rm built at run time in a script Claude Code can't read no longer prompts unless `CLAUDE_CODE_STRICT_INLINE_SHELL_RM_PROMPT=1`
- Fixed double-clicking a word in an expanded transcript row in fullscreen mode collapsing the row instead of selecting the word
- Fixed `claude mcp list`, `claude doctor` and `/status` reporting an empty `.mcp.json` as invalid
- Fixed `/btw` jumping the transcript to the bottom when asked while scrolled up in fullscreen
- Fixed sandboxed commands failing on WSL2 with `bwrap: Can't mkdir /mnt/c/Program Files/ClaudeCode` when the sandbox can write to the Windows drive
- Fixed scheduled wakeups (ScheduleWakeup) not firing while a background task was running in Agent SDK, IDE and `claude remote-control` sessions
- Fixed a mod's `prompt.submit` rewrite being silently dropped, sending the prompt as typed, for some prompts with a pasted image or an image that can't be read
- Fixed a Remote Control prompt being lost when another queued prompt in the same batch failed to deliver
- Fixed a Remote Control prompt that had passed its hooks being dropped from prompt history when Stop interrupted the next queued prompt's hook
- Fixed sign-in, MCP servers and project trust appearing lost on Linux after a sandboxed command left an empty `.config.json` in the config directory
- Fixed `/sandbox` reporting success when its setting could not be saved because the project folder is not writable; it now says nothing changed and why
- Fixed SDK and headless sessions staying in auto mode after the host switched to a model that doesn't support auto mode
- Fixed MCP servers named `constructor` or `prototype` in an MCP config never being connected
- Fixed tools of an MCP server named `constructor` or `toString` asking for permission in auto mode and bypass permissions mode
- Fixed a spurious "synced[0] commands path not found" plugin error at startup when another Claude Code process had just updated a claude.ai-synced plugin
- Fixed the Artifact tool advising a retry when a publish that requests connectors or other access was refused by the server or a proxy (HTTP 403); it now says so and what to tell the user
- Fixed Cowork cloud sessions staying on an old account plugin after a plugin reload that timed out or a restart that reused a recent sync
- Fixed document blocks being dropped from your own message sent while Claude is working
- Fixed Claude in Chrome asking for permission while no browser is connected; it now says the extension is not connected
- Fixed the fullscreen "Update installed" notice being hidden behind the idle "/clear to save tokens" hint; it now shows beside the hint
- Fixed a mod hook, with or without a `.catch`, being run again without end when it waits on another mod's noun that does its work outside the call
- Fixed the Claude apps gateway serving models that a policy's `availableModelsMatch: exact` or `deniedModels` blocks; it now answers 400 and leaves them out of its model lists
- Fixed the server-managed settings request to Anthropic carrying a third-party gateway's API key when a managed settings file sets `ANTHROPIC_BASE_URL`
- Fixed streams through a custom `ANTHROPIC_BASE_URL` being aborted after 180 seconds with no data arriving; they now wait 300 seconds, whether or not feature flags are loaded
- Fixed a mod's `tool.describe` or `prompt.section` answer that changed after `$.ui.invalidate` never reaching Claude; the new answer is now sent on the next turn
- Fixed a settings file being ignored when `enabledMcpjsonServers` or `disabledMcpjsonServers` held a single server name (letters, digits, - or _) as a plain string
- Fixed `claude plugin test` pausing a hook's time budget while a served `$` method it had called kept making `$` calls after answering
- Fixed high memory use after resuming a cloud or Remote Control session that had run many subagents
- Fixed plugin hooks being skipped when they pass a very deeply nested tool input or message on with next()
- Fixed a value a mod's hook passes to `next()`, returns, or sends to a `$` method being refused whole when one of its getters throws a `RangeError`; now only that key is refused
- Fixed `/usage`, the approaching-limit warning (terminal and VS Code) and the status line sometimes showing more than 100% used (anthropics/claude-code#92238)
- Fixed wrapped text mixing CJK or emoji with Latin words losing its last line or leaving a blank row at some terminal widths
- Fixed a cloud session sometimes ignoring the answer to a permission prompt or a question when the answer was given while the session's worker was being replaced
- Fixed bold, italic and other nested text styles running over table borders or being lost on wrapped rows
- Fixed Cowork cloud sessions running the old version of an account plugin changed, removed or disabled from another device until the session restarted
- Fixed deny and ask rules for an MCP server (`mcp__<server>`) not applying when the server's normalized name contains a double underscore
- Fixed long conversations losing newly attached images on every turn after one oversized image was refused by the API
- Fixed the `plugin_loaded` telemetry event reporting `has_hooks` as false for plugins whose hooks are a hooks module, built-in plugins included
- Fixed images attached while Claude is working (VS Code, desktop app, SDK) being sent at full size, which led to repeated image errors in long conversations
- Fixed the image coordinate hint being missing or slightly off for large near-square images on newer models
- Fixed feature flag, startup, fast mode, profile and feedback requests to Anthropic carrying the API key configured for a third-party gateway (`ANTHROPIC_BASE_URL`); Anthropic API keys are still sent
- Fixed a mod's hot reload ignoring a fix saved right after a failed reload; saving a mod file without changing it no longer reloads the mod
- Fixed mods loaded from source files being refused when a hook hands `$` to a function declaration imported from another file of the mod
- Fixed a regression in 2.1.296 where cloud and headless sessions could run an approved tool call twice if a new message arrived as the session resumed after a restart
- Fixed scheduled tasks being announced for the wrong minute: the scheduling tools now report each job's actual next run time
- Fixed mods' hooks being handed values with `__proto__` keys silently removed, which could skip a `tool.check` guard on a tool call another mod made
- Fixed `claude -p` saying nothing when a settings file fails validation: text-output runs now list the file and the invalid entry on stderr
- Fixed long pastes in terminals without bracketed paste losing all text after an invisible control character, such as a mis-decoded curly quote
- Fixed managed settings and organization policy not being fetched when the stored login's plan was changed locally on machines whose MDM or managed-settings file sets `forceLoginOrgUUID`
- Fixed MCP connections over HTTP hanging for 30 seconds and failing when a server never ends the body of its reply to a notification (anthropics/claude-code#99014)
- Fixed MCP servers added to a running headless or SDK session being connected before some policy checks ran; a blocked server is now reported as failed without being contacted
- Fixed `claude mcp list`, `claude mcp get` and subagent MCP servers starting a server that a policy check blocks; it is now reported as blocked without being started
- Fixed `/reload-plugins` not loading a plugin installed from another terminal a moment earlier
- Fixed blank rows appearing under CJK and emoji text squeezed into a one-cell column, as in a very narrow terminal
- Fixed text cut in the middle beside wide characters leaving a cell unused or being cut twice, and an emoji vanishing where a color changed inside it
- Fixed bare mode notices in background sessions telling you to restart without `--bare`, which keeps the mode; they now name `/stop` and `claude --resume`, as safe mode ones do
- Fixed `←` not saying why it stayed put over a queued message while Remote Control is on
- Fixed `$.http.fetch` in mods refusing a `304`, `204` or `205` response that declares a `Content-Length` over the 4 MiB body limit
- Fixed `/config` push notification toggles sending your account the previous setting instead of the one you just chose
- Fixed a cloud session leaving a reply unfinished when its worker was replaced just after the reply hit the output token limit
- Fixed Read failing on PDF page ranges in remote sessions on Linux that run without elevated privileges
- Fixed Enter answering a question or permission prompt that had been held back while you typed an unsent message
- Fixed a file attached to a message in a remote session being left out when its download stalled part way; the download is now tried again
- Fixed queued prompts sent as content blocks over `--input-format stream-json` running together without a line break when merged into one turn
- Fixed self-hosted runner sessions shutting down MCP servers added through an `--exec-path` wrapper's own `--mcp-config` when connectors change mid-session
- Fixed `claude plugin eval` passing runs that the API refused: a run that ends on an API error now scores 0 without grading and makes the suite exit 1
- Fixed permission prompts cutting off or wrapping too early when the reason text contains keycap or joined emoji
- Fixed `forceLoginOrgUUID` and `forceLoginMethod` from MDM or the managed-settings file being hidden or replaced by server-managed settings
- Fixed `--bare` sessions leaving out an MCP server named `constructor` or `prototype` that `--channels` asked for
- Fixed resuming a conversation from before `/clear` reattaching to the Remote Control session of the conversation after it
- Fixed a prompt starting with `/`, sent with the Agent SDK's `verbatimPrompts` option, running as a slash command when `CLAUDE_CODE_RESUME_INTERRUPTED_TURN` re-ran it after a restart
- Fixed background sessions started with `--safe-mode` silently leaving safe mode when the session was woken or restarted
- Fixed scheduled tasks and loops firing again after every turn, or firing early, during the repeated hour when daylight saving time ends
- Fixed the diff view listing a new file whose name begins or ends with a space under the wrong name
- Fixed MCP tool calls in headless and SDK sessions sometimes failing or running twice when a background reconnect closed the connection they were running on
- Fixed `/btw` side questions in non-interactive sessions not being cancelled when the session ends, and running a second time when the same request arrived again mid-run
- Fixed sandboxed commands on macOS being able to read or write a denied path by its real location when the denied path passes through a symlink
- Fixed sandbox `denyRead` and `allowRead` globs with braces, parentheses or backslashes in a folder's name being read differently by Claude Code's settings checks than by the sandbox
- Fixed sandbox glob `allowRead` and `allowWrite` entries not being re-checked when the directory they start from is replaced by a symlink
- Fixed worktree-isolated sessions accepting some awk programs the isolation guard should refuse
- Fixed `claude mcp add <name> -- <command> --background` being started as a background session
- Fixed a prompt or reply of `--bg` or `--background` to a background session being taken for the flag, which could start new sessions over and over instead of delivering it
- Fixed a custom slash command's embedded shell line running twice when a newer message interrupted the command while its prompt was being checked
- Fixed `--worktree` sessions leaving a folder behind in `.git/worktrees` in repositories using git's reftable ref storage
- Fixed `claude self-hosted-runner` sessions using Anthropic-managed git showing tracked files as staged deletions when starting in a reused clone whose remote is still empty
- Fixed Ultracode not being announced to scheduled tasks and other delivered headless turns when `ultracode` is on in settings
- Fixed MCP OAuth sign-in, token refresh and sign-out not sending configured `headers`/`headersHelper` values, which broke servers behind an authenticating proxy
- Fixed the Artifact tool reporting a spurious one-line difference against the live page, and refusing the publish, when a large page with a line break after `<head>` is published again unchanged
- Fixed `$.ui.open` reporting a mod's pane as placed in sessions where no surface draws it, such as Claude Code for VS Code and `claude -p`
- Fixed the `agent.spawn` mod hook not running when a finished subagent or a killed teammate is resumed: the hook's event now carries `resume`, and a mod can refuse it
- Fixed `claude plugin validate` rejecting a mod's `$.state` references when `plugin.json` has no `types` key and the contract is at `./types/index.d.ts`
- Fixed a mod's `dimColor` text looking the same as plain text under the dark ANSI theme and on 16-color terminals
- Fixed plan mode running a write (an MCP tool's, a file's, a shell command's) that a `PreToolUse` hook or a mod's `tool.check` hook allowed
- Fixed background subagents in auto mode sometimes sending their final report twice, once as the result and once as a message
- Fixed `SendMessage` not finding a subagent by name after the CLI restarted and resumed the session (names given before the last compaction still need the agent ID)
- Fixed replies cut off at the output token limit ending the turn silently, with no retry or error, after a request fell back to non-streaming mode
- Fixed Read garbling UTF-16LE files with a byte-order mark, and Write dropping byte-order marks or silently converting Windows-1252, Shift-JIS, GBK or UTF-16BE files to UTF-8 (now refused)
- Fixed cloud sessions sometimes leaving a message unanswered when the worker was replaced right after a compaction
- Fixed cloud sessions and `CLAUDE_CODE_RESUME_INTERRUPTED_TURN` sometimes answering a finished turn again after a restart, when a tool ended the turn and a skill loaded in the same step
- Fixed photos sent over Remote Control being dropped when their copy could not be saved on your computer; Claude now still sees the photo
- Fixed files sent over Remote Control sometimes not arriving in long-running sessions
- Fixed files of 30 to 35 MiB sent over Remote Control or to a cloud session not arriving
- Fixed a user-installed mod's `$.env.set` changing the environment or shell prefix that command hooks from managed settings start with
- Windows: Fixed the process-liveness check leaving orphaned PowerShell processes behind on busy machines until memory ran out
- Windows: Fixed PreToolUse and PermissionRequest hooks that set no shell failing open when Git for Windows isn't installed; a guard that fails now blocks the call
- Windows: Fixed Bash commands failing with "command not found" for a whole session when Git Bash did not report its PATH at startup
- Self-hosted runner: Improved what `setup` and `doctor` say when the runner's machine has no git credentials
- Self-hosted runner: Fixed sessions that wrote output before their first turn being left with no release timer, ignoring `--retire-at` and delaying shutdown
- Improved the error shown when a cloud session is refused because your claude.ai login was rejected or has expired: it now tells you to sign in again with `claude auth login`
- Improved enforcement of managed permission rules, managed hooks and organization MCP tool names against user-installed mods
- Improved memory and disk use when PDFs are @-mentioned
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