Claude Code v2.1.284：默认模型换为 Sonnet 5.5

What's changed

• Added Claude Sonnet 5.5 (claude-sonnet-5-5), now the default Sonnet model on the Anthropic API — 1M context, $2/$10 per Mtok with $0.20/Mtok cache reads
• Added a "Yes, but ask again next time" answer to auto mode's prompt before a read outside the working directories, so you can allow that one read and still be asked about later ones
• Added dollar amounts to the Claude apps gateway spend limit in /usage and the status line (for example "$271.40 / $500.00 spent this month") when the gateway runs this version or later; the status line's rate_limits.spend_limit also gains used_usd, limit_usd and period
• Added effortSlider:decreaseEffort, increaseEffort and toggleUltracode keybinding actions, so the /effort slider's arrow and Tab keys can be rebound in keybindings.json
• Added /rate-limit-options to /help and the command menu for claude.ai subscribers, so the usage-limit notices that mention it point to a command you can find
• Added /mcp reconnect all in the interactive terminal to retry every MCP server that failed to connect or needs authentication at once
• Added Claude apps gateway startup warnings when a managed policy's availableModels is empty, or leaves out the model Claude Code starts on without setting model or enforceAvailableModels
• Added auth: { google: {} } for Claude apps gateway telemetry.forward_to destinations, so telemetry can be exported straight to Google Cloud's OTLP endpoint using the gateway's Google Cloud credentials
• Added certificate client authentication (private_key_jwt) between the Claude apps gateway and its identity provider, for identity providers that issue certificate credentials instead of client secrets
• Fixed a damaged response stream showing raw errors such as "JSON Parse error" or "undefined is not an object", or writing the word "undefined" into an answer, instead of being retried or reported as an interrupted response
• Fixed an overloaded or server error arriving right after a thinking block ending the turn with an error instead of being retried
• Fixed "Prompt is too long" errors that persisted after compacting: when the compacted request is still too long, Claude Code now compacts once more, keeping less of the recent conversation
• Fixed a session whose model is unavailable, with no fallback model left, showing a bare "is currently unavailable" message (or "Something went wrong" in cloud sessions) instead of the model-unavailable notice and its Learn more link
• Fixed Agent SDK sessions crashing when a user message contains an image with a malformed source, and failing on every later turn after a malformed document block; a malformed image is now replaced with an explanatory note
• Fixed MCP tool calls in a resumed session failing with "No such tool available" while their server was still connecting; the call now waits up to 10 seconds for the server
• Fixed repeated calls to the plan-usage endpoint after it rate-limits or rejects your login: /usage, /extra-usage and IDE usage views now back off instead of re-asking
• Fixed claude mcp add reporting success when managed settings restrict MCP servers to plugins; it now refuses and says what to do, instead of saving a server that never loads
• Fixed the /plugin configure screen: boolean options are now a true/false choice instead of free text, number options refuse invalid input, and ←/→ change an options field instead of switching tabs
• Fixed ANTHROPIC_FOUNDRY_RESOURCE being interpolated into the Foundry endpoint host unvalidated; a value that is not a plain resource name is now refused
• Fixed Claude Desktop behind a Claude apps gateway offering no 1M context option: the gateway now marks each 1M-capable model for Desktop automatically
• Fixed ↓ in shell mode selecting a hidden background-tasks pill, which stopped Backspace and Ctrl+U from editing the prompt
• Fixed Bash tool failing on Windows with many plugins enabled: plugin bin/ directories that don't exist are no longer added to PATH, and inherited entries aren't added twice
• Fixed sparsePaths plugin marketplaces cloning empty and replacing a working local copy on older git (before 2.39), which failed every refresh with "marketplace.json file is no longer present"
• Fixed fullscreen rendering erasing the terminal output above the session when [ in transcript mode writes the conversation to scrollback (macOS and Linux)
• Fixed fullscreen scroll position jumping to the previous message or to the bottom when a reply finished streaming while scrolled up
• Fixed tab bars in dialogs such as /config and /plugin breaking the title and tab labels mid-word in a narrow terminal; a tab that doesn't fit now moves to the next line whole
• Fixed the /model picker showing "+1 model" below the list after scrolling to the last model; the count now covers only the models below the visible rows
• Fixed /keybindings writing Backspace and Delete bindings for a footer action that does nothing into the generated keybindings.json
• Fixed a rebound agent panel close key (footer:close) typing "x" instead of itself on the row of the agent you're viewing
• Fixed vim mode . not repeating text typed very fast (for example over ssh or in tmux) or pasted without bracketed paste, and leaving the prompt in INSERT mode after repeating a change with nothing typed (such as cw then Esc)
• Fixed vim mode leaving the cursor on an image placeholder's opening bracket after dd on the last line or yy at the end of the prompt, where r or x would break or delete the image
• Fixed a key pressed the instant the terminal regained focus answering the Remote Control enable prompt before its short safety delay restarted
• Fixed the workspace trust dialog appearing a second time after switching renderers or updating when Claude Code was started in the home directory
• Fixed rules symlinked into .claude/rules from outside the project being skipped without ever showing the external-imports approval prompt; a .claude directory symlinked from outside the project now asks for the same approval
• Fixed plugins from marketplaces, claude.ai and npm pre-approving their own tools via allowed-tools under managed allowManagedPermissionRulesOnly; only plugins from an official Anthropic source or a source that managed settings vouch for keep that pre-approval
• Fixed a failed first claude plugin install leaving the plugin enabled and recorded when a dependency's version range could not be met
• Fixed the debug log dropping a failed hook's stderr when the hook also wrote to stdout, and logging nothing for a failed hook with no output; failed hooks now also log their status code
• Fixed {"decision":"block"} returned by Elicitation and ElicitationResult hooks being ignored; it now declines the MCP elicitation, as exit code 2 does
• Fixed sessions launched without the SendMessage tool (such as by Claude Desktop) still being told to message other sessions with it
• Fixed a photo sent from the Claude app over Remote Control being lost when its queued message was pulled back into the terminal prompt to edit, and the cursor moving one character for a photo with no caption
• Fixed typing a message during an automatic usage-limit wait taking the wait out of the "Continue automatically at usage limit" setting's control when that turn hit the limit again
• Fixed usage-limit warnings suggesting /upgrade to users already on the highest Max plan; the warnings and /upgrade itself now point at /usage-credits when it is available
• Fixed the Explore subagent switching to Opus on the Claude API when the session runs a model ID Claude Code doesn't recognize, such as a custom model behind a proxy; Explore now inherits that model
• Fixed /loop status updates in self-paced mode often not being shown because Claude wrote them only in its reasoning; Claude now writes each update, and the outcome when the loop stops, as visible text