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DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

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Claude Code v2.1.48

12 entries read diff v2.1.47 → v2.1.48 Markdown

This release introduces a major new worktree workflow for isolated development, adds HTTP hooks and a new ConfigChange hook event, and removes the experimental MCP-CLI feature. Users can now work in git worktrees with optional tmux integration, and exclude specific CLAUDE.md files using glob patterns.

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11 entries

Changesopen

Git Worktree Mode#

What

Create and work in isolated git worktrees directly from Claude Code, with full session management and cleanup prompts.

Usage
# Start Claude Code with a new worktree
claude --worktree
claude -w

# Start with a named worktree
claude --worktree=my-feature

# Combine with tmux for parallel sessions
claude --worktree --tmux
Details
  • Creates a new git worktree in .claude/worktrees/ with a dedicated branch based on HEAD
  • Automatically switches the session's working directory to the worktree
  • On session exit, prompts to keep or remove the worktree and associated tmux session
  • Symlinks configured directories (like node_modules) from main repo to avoid disk bloat
  • Copies settings.local.json and configures git hooks from the main repository
  • The worktree branch is automatically deleted when removing the worktree
Evidence

New -w, --worktree [name] flag and CreateWorktree tool (search for "Create a new git worktree for this session")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

CreateWorktree Tool#

What

A new built-in tool that allows Claude to create worktrees mid-session when users request isolated work.

Usage
User: "Start a worktree for this feature"
User: "Work in isolation on a separate branch"
Details
  • Tool activates when user asks to "work in isolation" or "start a worktree"
  • Must be in a git repository and not already in a worktree
  • Creates worktree with optional custom name
  • Session automatically switches to the new worktree directory
Evidence

Tool description (search for "Use this tool when the user asks to work in isolation")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

HTTP Hooks#

What

A new hook type that sends HTTP POST requests instead of executing shell commands, enabling webhook-style integrations.

Usage (in settings.json or CLAUDE.md):

{
  "hooks": {
    "PreToolUse": [{
      "type": "http",
      "url": "https://your-server.com/hook",
      "headers": {
        "Authorization": "Bearer $MY_TOKEN"
      },
      "timeout": 30
    }]
  }
}
Details
  • Supports environment variable expansion in headers ($VAR_NAME or ${VAR_NAME} syntax)
  • Configurable timeout per request
  • JSON response parsing with optional logging
  • Works with all hook events including the new ConfigChange event
Evidence

New http hook type definition (search for "HTTP hook type")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

ConfigChange Hook Event#

What

A new hook event that fires when configuration files change during a session, allowing validation and blocking of config changes.

Details
  • Fires when skills, settings, or CLAUDE.md files are modified
  • Can block changes by returning exit code 2
  • Input includes source (user_settings, project_settings, etc.) and file_path
  • Useful for enforcing configuration policies
Evidence

New ConfigChange hook event (search for "ConfigChange")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

CLAUDE.md Exclude Patterns#

What

Exclude specific CLAUDE.md files from loading using glob patterns or absolute paths.

Usage (in settings.json):

{
  "memory": {
    "excludePatterns": [
      "/home/user/monorepo/CLAUDE.md",
      "**/node_modules/**/CLAUDE.md",
      "**/some-dir/.claude/rules/**"
    ]
  }
}
Details
  • Uses picomatch for glob pattern matching
  • Patterns match against absolute file paths
  • Only applies to User, Project, and Local memory types (Managed/policy files cannot be excluded)
Evidence

New excludePatterns setting (search for "Glob patterns or absolute paths of CLAUDE.md files to exclude from loading")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Tmux Integration for Worktrees#

What

Automatically create tmux sessions when starting worktrees, with iTerm2 native pane support.

Usage
claude --worktree --tmux
claude -w --tmux=classic  # Use traditional tmux instead of iTerm2 integration
Details
  • Creates a tmux session for parallel worktree work
  • Uses iTerm2 native panes when available for better integration
  • Use --tmux=classic for traditional tmux behavior
  • Session management options on exit: keep both, keep worktree only, or remove all
Evidence

New --tmux flag (search for "Create a tmux session for the worktree")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Model Capability Descriptions#

What

Added explicit descriptions for model thinking capabilities in the schema.

Details
  • New effortLevels field describes available effort levels for models
  • New supportsAdaptiveThinking field indicates whether a model supports adaptive thinking (Claude decides when and how much to think)
Evidence

New schema descriptions (search for "Whether this model supports adaptive thinking")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Git Diff for Issue Creation#

What

Improved git diff generation when creating issues, with better handling of edge cases.

Details
  • Handles shallow clones gracefully with HEAD-only mode
  • Falls back to HEAD-only mode when no remote or merge-base is found
  • Captures untracked files with size limits (500MB per file, 5GB total)
  • Excludes binary files from untracked file capture
  • Filters out excessively large files automatically
Evidence

New shallow clone detection (search for "Shallow clone detected, using HEAD-only mode for issue")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

MCP Server Authentication Caching#

What

Caches MCP servers that need authentication to reduce redundant connection attempts.

Details
  • Stores needs-auth status in mcp-needs-auth-cache.json
  • Skips connection attempts for cached servers
  • Logged as "Skipping connection (cached needs-auth)"
Evidence

New cache file (search for "mcp-needs-auth-cache.json")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Background Agent UX Improvements#

What

Better messaging for background agent management.

Details
  • New "Press again to kill all background agents" message for confirmation
  • Clearer output file instructions
Evidence

New UI text (search for "Press again to kill all background agents")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

IDE Opening Feedback#

What

Better feedback when opening worktrees or projects in IDEs.

Details
  • Clearer messages for manual IDE opening
  • Specific messaging for worktree vs project contexts
Evidence

New message handling (search for "Please open the")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

2 entries

Bug Fixesopen

#

  • Fixed path traversal detection (search for "path traversal detected")
  • Added validation for non-empty strings and patterns (search for "Expected a non-empty string")

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

MCP-CLI Removed#

What

The experimental mcp-cli command-line interface for MCP servers has been removed.

Details
  • The ENABLE_EXPERIMENTAL_MCP_CLI environment variable is no longer recognized
  • The mcp-cli command (info, call, servers, tools, grep, resources, read) is removed
  • MCP tools continue to work through the normal tool interface

Impact: If you relied on mcp-cli commands in bash scripts or hooks, migrate to using MCP tools through Claude's standard tool interface.

Evidence

Removal of mcp-cli infrastructure (removed strings: "mcp-cli info", "mcp-cli call", "ENABLE_EXPERIMENTAL_MCP_CLI")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

1 entry

Notesopen

#

The worktree feature requires being in a git repository and having git installed. Tmux integration requires tmux to be installed (sudo apt install tmux on Linux). iTerm2 users will get native pane integration when using --tmux without the =classic suffix.

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

Verbatim
No official entry

Not individually listed upstream

v2.1.48 does not have its own entry in Anthropic’s official changelog, because prerelease builds are often folded into a neighbouring release. Browse the full changelog for the closest official notes. Everything else on this page came out of the bundle instead, which is why the two lists don't match.

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