tweakcc
A CLI that patches Claude Code: custom system prompts, themes, toolsets, AGENTS.md support and UI tweaks
Install
npx tweakccOr pnpm dlx tweakcc.
This is third-party code. Review the repository files before installing.
What it does
tweakcc modifies an installed Claude Code by patching its cli.js or native binary. An interactive menu lets you rewrite system prompts, build a theme, define toolsets for the /toolset command, set input highlighters, spinner verbs and animations, message styling and table formats. It adds AGENTS.md support and per-subagent model selection, and speeds up startup with non-blocking MCP connections. Settings live in ~/.tweakcc/config.json and are reapplied after Claude Code updates, with backup restore, an API and ad-hoc script patches.
Who it is for. For advanced Claude Code users who want to tune behavior and looks beyond the built-in settings.
Good fit when
- You need to change Claude Code's system prompt for your team
- You want Claude Code to read AGENTS.md
- You need custom toolsets or subagent models
Not a fit when
- Company policy forbids modifying tool binaries
- You need stability with no risk of breakage after Claude Code updates
Example request
Use tweakcc to enable AGENTS.md support and set Sonnet for the Explore subagentLimitations
This is an unofficial modification: Claude Code updates overwrite the patches, which must be reapplied with npx tweakcc --apply. Some patches unlock hidden features or loosen permission checks, which deserves care. adhoc-patch creates no backup and can run a script from a URL. Claude Code itself needs access to Anthropic.
How to disable. Run tweakcc --restore to bring Claude Code back from the backup, or reinstall Claude Code.
Security check
- Modifies Claude Code executables
- Some patches loosen permission checks and can run scripts from URLs
README in short
The README lists features and the new 4.0 patches, supported Claude Code install types and running via npx without install. It explains how patching and reapplying work and covers remote config, the unpack, repack and adhoc-patch commands and the programmatic API. Most of the document details individual features with examples. MIT licensed.
FAQ
What happens after a Claude Code update?
Patches are lost, but settings remain in config.json and can be reapplied with --apply.
Does it work with the native install?
Yes, code is extracted from the binary, patched and repacked on macOS, Windows and Linux.
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