Anthropic Release Notes

• Added guard against launching Claude Code inside another Claude Code session
• Fixed Agent Teams using wrong model identifier for Bedrock, Vertex, and Foundry customers
• Fixed a crash when MCP tools return image content during streaming
• Fixed /resume session previews showing raw XML tags instead of readable command names
• Improved model error messages for Bedrock/Vertex/Foundry users with fallback suggestions
• Fixed plugin browse showing misleading "Space to Toggle" hint for already-installed plugins
• Fixed hook blocking errors (exit code 2) not showing stderr to the user
• Added speed attribute to OTel events and trace spans for fast mode visibility
• Added claude auth login, claude auth status, and claude auth logout CLI subcommands
• Added Windows ARM64 (win32-arm64) native binary support
• Improved /rename to auto-generate session name from conversation context when called without arguments
• Improved narrow terminal layout for prompt footer
• Fixed file resolution failing for @-mentions with anchor fragments (e.g., @README.md#installation)
• Fixed FileReadTool blocking the process on FIFOs, /dev/stdin, and large files
• Fixed background task notifications not being delivered in streaming Agent SDK mode
• Fixed cursor jumping to end on each keystroke in classifier rule input
• Fixed markdown link display text being dropped for raw URL
• Fixed auto-compact failure error notifications being shown to users …

• Fixed agent teammate sessions in tmux to send and receive messages
• Fixed warnings about agent teams not being available on your current plan
• Added TeammateIdle and TaskCompleted hook events for multi-agent workflows
• Added support for restricting which sub-agents can be spawned via Task(agent_type) syntax in agent "tools" frontmatter
• Added memory frontmatter field support for agents, enabling persistent memory with user, project, or local scope
• Added plugin name to skill descriptions and /skills menu for better discoverability
• Fixed an issue where submitting a new message while the model was in extended thinking would interrupt the thinking phase
• Fixed an API error that could occur when aborting mid-stream, where whitespace text combined with a thinking block would bypass normalization and produce an invalid request
• Fixed API proxy compatibility issue where 404 errors on streaming endpoints no longer triggered non-streaming fallback
• Fixed an issue where proxy settings configured via settings.json environment variables were not applied to WebFetch and other HTTP requests on the Node.js build
• Fixed /resume session picker showing raw XML markup instead of clean titles for sessions started with slash commands
• Improved error messages for API connection failures — now shows specific cause (e.g., ECONNREFUSED, SSL errors) instead of generic "Connection error"
• Errors from invalid managed settings are now surfaced …

• Claude Opus 4.6 is now available!
• Added research preview agent teams feature for multi-agent collaboration (token-intensive feature, requires setting CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1)
• Claude now automatically records and recalls memories as it works
• Added "Summarize from here" to the message selector, allowing partial conversation summarization.
• Skills defined in .claude/skills/ within additional directories (--add-dir) are now loaded automatically.
• Fixed @ file completion showing incorrect relative paths when running from a subdirectory
• Updated --resume to re-use --agent value specified in previous conversation by default.
• Fixed: Bash tool no longer throws "Bad substitution" errors when heredocs contain JavaScript template literals like ${index + 1}, which previously interrupted tool execution
• Skill character budget now scales with context window (2% of context), so users with larger context windows can see more skill descriptions without truncation
• Fixed Thai/Lao spacing vowels (สระ า, ำ) not rendering correctly in the input field
• VSCode: Fixed slash commands incorrectly being executed when pressing Enter with preceding text in the input field
• VSCode: Added spinner when loading past conversations list

• We've launched Claude Opus 4.6, our most intelligent model for complex agentic tasks and long-horizon work. Opus 4.6 recommends adaptive thinking (thinking: {type: "adaptive"}); manual thinking (type: "enabled" with budget_tokens) is deprecated. Opus 4.6 does not support prefilling assistant messages. Learn more in What's new in Claude 4.6.
• The effort parameter no longer requires a beta header and now supports Claude Opus 4.6. Effort replaces budget_tokens for controlling thinking depth on new models.
• We've launched the compaction API in beta, providing server-side context summarization for effectively infinite conversations. Available on Opus 4.6.
• We've introduced data residency controls, allowing you to specify where model inference runs with the inference_geo parameter. US-only inference is available at 1.1x pricing for models released after February 1, 2026. …

Claude Opus 4.6 launch

We’ve upgraded our smartest model and improved its coding skills. Read our blog post for more information: Introducing Claude Opus 4.6.

Introducing Claude for PowerPoint

Claude is now available as an add-in for PowerPoint. Read more here: Use Claude for PowerPoint.

Claude for Excel improvements

We’ve updated Claude for Excel so it uses Opus 4.6 and supports native Excel operations such as pivot table editing and conditional formatting. See our updated article for more information: Using Claude for Excel.

• Added session resume hint on exit, showing how to continue your conversation later
• Added support for full-width (zenkaku) space input from Japanese IME in checkbox selection
• Fixed PDF too large errors permanently locking up sessions, requiring users to start a new conversation
• Fixed bash commands incorrectly reporting failure with "Read-only file system" errors when sandbox mode was enabled
• Fixed a crash that made sessions unusable after entering plan mode when project config in ~/.claude.json was missing default fields
• Fixed temperatureOverride being silently ignored in the streaming API path, causing all streaming requests to use the default temperature (1) regardless of the configured override
• Fixed LSP shutdown/exit compatibility with strict language servers that reject null params
• Improved system prompts to more clearly guide the model toward using dedicated tools (Read, Edit, Glob, Grep) instead of bash equivalents (cat, sed, grep, find), reducing unnecessary bash command usage
• Improved PDF and request size error messages to show actual limits (100 pages, 20MB)
• Reduced layout jitter in the terminal when the spinner appears and disappears during streaming
• Removed misleading Anthropic API pricing from model selector for third-party provider (Bedrock, Vertex, Foundry) users

• Added pages parameter to the Read tool for PDFs, allowing specific page ranges to be read (e.g., pages: "1-5"). Large PDFs (>10 pages) now return a lightweight reference when @ mentioned instead of being inlined into context.
• Added pre-configured OAuth client credentials for MCP servers that don't support Dynamic Client Registration (e.g., Slack). Use --client-id and --client-secret with claude mcp add.
• Added /debug for Claude to help troubleshoot the current session
• Added support for additional git log and git show flags in read-only mode (e.g., --topo-order, --cherry-pick, --format, --raw)
• Added token count, tool uses, and duration metrics to Task tool results
• Added reduced motion mode to the config
• Fixed phantom "(no content)" text blocks appearing in API conversation history, reducing token waste and potential model confusion
• Fixed prompt cache not correctly invalidating when tool descriptions or input schemas changed, only when tool names changed
• Fixed 400 errors that could occur after running /login when the conversation contained thinking blocks
• Fixed a hang when resuming sessions with corrupted transcript files containing parentUuid cycles
• Fixed rate limit message showing incorrect "/upgrade" suggestion for Max 20x users when extra-usage is unavailable
• Fixed permission dialogs stealing focus while actively typing …

• Added tool call failures and denials to debug logs
• Fixed context management validation error for gateway users, ensuring CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1 avoids the error
• Added --from-pr flag to resume sessions linked to a specific GitHub PR number or URL
• Sessions are now automatically linked to PRs when created via gh pr create
• Fixed /context command not displaying colored output
• Fixed status bar duplicating background task indicator when PR status was shown
• Windows: Fixed bash command execution failing for users with .bashrc files
• Windows: Fixed console windows flashing when spawning child processes
• VSCode: Fixed OAuth token expiration causing 401 errors after extended sessions