What
New CLI flags for launching Claude Code via deep links with shell-safe, base64url-encoded parameters. This enables external applications (such as IDE extensions or web UIs) to open Claude Code with a prefilled prompt and working directory without worrying about shell escaping.
Usage
claude --prefill-b64 <base64url-encoded-prompt> --deep-link-cwd-b64 <base64url-encoded-cwd>
claude --deep-link-repo=<repo> --deep-link-origin=<origin> --deep-link-last-fetch=<timestamp>Details
--prefill-b64: Base64url-encoded text to prefill into the prompt--deep-link-cwd-b64: Base64url-encoded working directory path--deep-link-repo: Repository identifier for the deep link--deep-link-origin: Origin identifier for deep-link launches--deep-link-last-fetch: Timestamp of last fetch for deep-link context- Includes extensive validation: rejects Unicode bidirectional control characters, UNC/network paths, and paths with un-quotable characters (single quotes, backslashes, exclamation marks, dollar signs, newlines)
- Error messages guide users to reinstall to a safe path if their Claude binary path contains shell metacharacters
Evidence
Deep link argument construction (search for "--deep-link-cwd-b64" and "--prefill-b64")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.