CwdChanged and FileChanged Hooks / Claude Code v2.1.83

What

Two new hook event types that trigger automation when the working directory changes or when specific files are modified.

Usage in .claude/hooks.json:

{
  "hooks": {
    "CwdChanged": [{
      "command": "my-script.sh",
      "timeout": 10000
    }],
    "FileChanged": [{
      "command": "on-file-change.sh",
      "matcher": "src/**/*.ts",
      "timeout": 10000
    }]
  }
}

Details

CwdChanged: Fires after the working directory changes. Input JSON includes old_cwd and new_cwd. Hook output can include watchPaths to dynamically register additional file watchers via hookSpecificOutput
FileChanged: Fires when a watched file changes, is added, or is removed. Input JSON includes file_path and event (one of change, add, unlink). The matcher field specifies file glob patterns to watch
Both hook types set CLAUDE_ENV_FILE — write bash exports there to inject environment variables into subsequent BashTool commands
File watching uses chokidar under the hood for cross-platform filesystem monitoring

Evidence

New hook types (search for "CwdChanged", "FileChanged", "cwdchanged-hook-", "filechanged-hook-")

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