Claude Code in September 2026 introduced Claude Opus 5.5 and Sonnet 5.5 as default models with improved pricing and 1M context windows, alongside major workflow improvements for remote sessions, diff review, and agent management.
Models and pricing
- Claude Opus 5.5 and Sonnet 5.5 defaults: Both models now available with 1M context windows and improved pricing including cache read discounts. Model family choices like "Opus (latest)" let you pin a family instead of a version for automatic upgrades.
- Claude Fable 5.1 launch: New default model with 1M context window and reduced pricing ($10/$50 per million tokens, $0.25 per million for cache reads).
Session and remote work
- Session forking: Duplicate remote-control sessions directly from the Claude app; the fork runs as a background process while the original continues uninterrupted.
- Fast mode for remote sessions: Hosts can enable faster performance with a setting or /fast command in Remote sessions.
- Send-Now shortcut: Interrupt the turn and send all queued messages instantly with Ctrl+Enter or Ctrl+X Ctrl+S.
- Desktop app launcher: New claude --desktop command launches the desktop app in your current directory or resumes an existing session.
Code review and editing
- Diff panel in fullscreen: View uncommitted changes alongside the conversation as Claude edits them; toggle with /diff. VSCode now shows Accept and Reject buttons under each change for one-by-one review.
- Bookmarks for responses: Save and pin Claude's responses in a side panel for easy reference and later lookup.
- Copy response button: Quickly copy generated code from AI replies in VSCode.
Agent and task management
- Agent map with background shells: VSCode displays an "N agents" footer pill showing sub-agents with cards, stop controls, and read-only transcripts. The map now also shows background shells and tasks with stop buttons.
- Tasks view improvements: Status icons, improved layout with persistent headers, pagination, and mouse wheel scrolling for better navigation with many tasks.
- Message context display: Messages now show expandable rows revealing associated terminal output, browser tabs, browser instructions, and code snippets sent with them.
Configuration and management
- MCP server management: Organizations can provision HTTP/SSE MCP servers to all users via managedMcpServers setting. The MCP servers dialog now includes an Add form and Remove action for easy management without leaving the IDE.
- Hooks and permission rules dialogs: View, add, edit, or remove hooks and permission rules in user, project, and local settings; managed entries remain read-only.
- Plugin configuration: Use claude plugin configure to view and set options; VSCode shows a form when installing plugins with unset options.
- Skill Doctor command: Identify unused loaded skills and their context cost to optimize your setup.
- Prompt audit command: Check CLAUDE.md files, skills, agents, and commands for outdated prompting patterns.
Interface and accessibility
- Output style switching: New /output-style command lists and changes styles in VSCode, Remote, and headless sessions. A walkthrough in the Output styles menu guides you through building custom styles.
- Status and Sandbox dialogs: VSCode adds /status to view session details and /sandbox to switch to sandbox mode and configure excluded commands.
- Export conversation: /export command lets you copy or save the entire chat as plain text from VSCode.
Some other features were also released this month but are not listed here.