What is sidekick?
sidekick is a Claude Code mod by FynnXland that checks your message before it is sent, by rules and, where worthwhile, briefly with Haiku 5.5 (Sonnet 5.5 writes rewritten versions in level auto): a hint line under your message or a. It is listed under Security and has 3 GitHub stars.
| Type | Claude code mod |
|---|---|
| Author | FynnXland |
| Repository | FynnXland/fynn-mods |
| Popularity | 3 GitHub stars |
| Category | Security |
| Security | Low risk (84/100) |
| Rank | #802 of 5,272 Claude Code mods; #107 in Security |
| License | MIT |
| Last commit | 2026-10-09 |
| Hooks | 7 events |
| Sees | Bash|PowerShell calls, every prompt, every skill |
| Draws on | UserMessage, AbovePrompt, SessionMode, CommandOutput |
Is sidekick safe to install?
sidekick scores 84/100 on the MCPMods security check: Low risk. Things to review: watches every prompt or event. It passed 6 of 8 checks.
Mod footprints come from claude plugin validate, which lists every event a mod hooks and every API call it makes without running it.
| Check | Result |
|---|---|
| No network access | Pass |
| Starts no processes | Pass |
| Writes no files or config | Pass |
| Doesn't read environment variables | Pass |
| Watches every prompt or event | Review |
| Drives Claude (model calls, prompts) | Note |
| Passes claude plugin validate | Pass |
| Has an open-source license | Pass |
API calls in its code
| Call | What it means |
|---|---|
$.clock.every | |
$.clock.now | |
$.command.list | |
$.command.register | |
$.command.run | drives Claude |
$.model.complete | drives Claude |
$.model.fork | drives Claude |
$.prompt.fill | writes the prompt box |
$.prompt.read | |
$.prompt.submit | drives Claude |
$.session.id | |
$.session.messages | reads the transcript |
$.session.root | |
$.session.surfaces | |
$.session.usage | |
$.state.get | |
$.state.set | |
$.store.delete | keeps its own state |
$.store.get | keeps its own state |
$.store.keys | keeps its own state |
$.store.set | keeps its own state |
$.ui.ask | draws interface |
$.ui.invalidate | draws interface |
$.ui.resolve | draws interface |
$.ui.toast | draws interface |
How do I install sidekick?
- Check your Claude Code version. Mods need Claude Code 2.1.287 or later and are on by default.
claude --version
- Read its footprint. This lists every event it hooks and every API call it makes, without running it.
git clone https://github.com/FynnXland/fynn-mods claude plugin validate ./fynn-mods/mods/sidekick
- Install it. Run this in your terminal, then /reload-plugins in an open session.
claude plugin marketplace add FynnXland/fynn-mods && claude plugin install sidekick@fynn-mods
Or ask Claude to set it up
Paste this into Claude Code and it installs sidekick for you:
Install the "sidekick" Claude Code mod from https://github.com/FynnXland/fynn-mods/tree/main/mods/sidekick. Run claude plugin validate on it first and show me what it can access before you enable it.
More from FynnXland/fynn-mods
This repository has 6 Claude Code mods on MCPMods.
- clawd-buddy: Animated pixel mascot Clawd above the prompt: reacts to Claude's work, waiting times, idle time, time of day, the mouse (Low risk)
- cost-ledger: Cost ledger across all chats: after every answer it records the chat cost (as /cost), tokens per model and model calls m (Low risk)
- limit-bars: Bars for the 5-hour and weekly usage limits above the prompt, a ring showing how long the prompt cache stays warm, and a (Review before installing)
- quick-replies: Claude Code's own next-message suggestion as a button above Clawd; click it, type 1 in the empty prompt, or send just 1 (Low risk)
- worklist: To-do sidebar next to the chat: queue tasks, even while Claude is working. When Claude is clearly done, the to-do is che (Low risk)