Claude Code version 2.1.280 introduces Claude Opus 5.5 as the new default Opus model, featuring a 1M context window and updated pricing. The update also adds mouse wheel support for scrolling lists in fullscreen mode and allows configuration of MCP tool description length limits.
Claude Code version 2.1.278 changes the default behavior for Claude API, Enterprise, Bedrock, Vertex, Foundry, and gateway users to use the server-side classifier in auto mode. This shift eliminates charges for classifier overhead, with a warning displayed if a billed fallback occurs.
Anthropic released Claude Code v2.1.277, introducing support for the AGENTS.md file as a fallback for project instructions and adding several configuration options for the Claude apps gateway.
Version 2.1.276 resolves a regression introduced in 2.1.275 where every request failed with a 400 error containing the input tag 'advisor_20260301'. This issue occurred specifically when the ANTHROPIC_BASE_URL environment variable pointed at a proxy or gateway.
Claude Code version 2.1.275 introduces a new 'send-now' keybinding that interrupts the current turn to queue messages, and synchronizes skills and plugins from claude.ai accounts to terminal sessions. The update also resolves critical stability issues where malformed transcripts or memory entries caused crashes during session resumption.
Anthropic released Claude Code version 2.1.274, introducing new visibility into system resource usage and significant updates to the Model Context Protocol (MCP) client behavior.
Claude Code version 2.1.273 introduces new request headers for LLM gateways, enhances session management features, and resolves numerous permission and connectivity bugs across desktop, web, and Slack integrations.
Anthropic released Claude Code v2.1.271, introducing fast mode for Remote sessions, mouse support in the fullscreen config panel, and stricter per-command domain controls for sandboxed auto mode.
Anthropic released Claude Code v2.1.269, introducing new evaluation tools for plugins, a sub-agent visualization in VSCode, and extensive stability improvements across terminal and cloud sessions.
Anthropic released Claude Code version 2.1.268, introducing gateway pricing configuration, significant bug fixes for third-party endpoints and network requests, and various UI improvements.
Claude Code version 2.1.267 introduces a new `maxEffortLevel` setting to cap effort across providers, alongside significant fixes for prompt-cache stability and session resumption. The update also addresses various bugs in VS Code integration, Claude Tag, and cloud scheduling.
Claude Code version 2.1.266 resolves a regression introduced in version 2.1.265 that disrupted LLM-gateway and proxy configurations.
Claude Code version 2.1.265 introduces several functional updates alongside a large number of stability improvements. Key additions include support for pointing `--plugin-dir` at a folder of plugins to load them dynamically, and the inclusion of `user.email` and `user.groups` in telemetry sent through the Claude apps gateway.
Claude Code version 2.1.261 introduces new configuration options for command and background-task output limits, raising the inline character threshold to 128K. It also adds a `/skill-doctor` command to identify unused skills and their context costs, allowing users to prune them effectively.
Anthropic released Claude Code v2.1.260, introducing a fullscreen diff panel for uncommitted changes and adding the /advisor command to headless sessions. The update also resolves several critical issues with prompt caching on Claude Fable 5.1 and fixes permission rule handling in the Bash sandbox.
Claude Code version 2.1.259 introduces several new configuration options and fixes a wide range of stability issues in session management and tool execution.
Claude Code version 2.1.257 introduces Claude Fable 5.1 as the new default Fable model, featuring a 1M context window and specific pricing tiers. The update also adds time format settings for timestamps and enhances security with a Containment Escape rule in auto mode.
Claude Code version 2.1.252 addresses several stability and configuration bugs affecting macOS users and remote sessions.
Claude Code version 2.1.251 introduces new hook events for model switching, live streaming of foreground subagent tool calls, and a spend limit bar in the usage interface. The update also changes the default model for seat-based Enterprise subscriptions to Opus 5.
Claude Code v2.1.248 introduces a new `--restricted` mode that removes built-in command execution tools and ignores user settings to enhance security. The update also adds cross-session messaging capabilities between sessions on the same machine across Bedrock, Vertex, and Foundry environments.