What is mermaid-c4-zoom?
mermaid-c4-zoom is a Claude Code mod by testy-cool that a side pane in Claude Code that draws mermaid diagrams as colored text art, with C4-style zoom: click a box to see the level inside it. It is listed under Interface and has no public popularity data yet.
| Type | Claude code mod |
|---|---|
| Author | testy-cool |
| Repository | testy-cool/mermaid-c4-zoom |
| Popularity | no public popularity data yet |
| Category | Interface |
| Security | Low risk (84/100) |
| Rank | #4,798 of 5,272 Claude Code mods; #1,966 in Interface |
| License | MIT |
| Last commit | 2026-10-08 |
| Hooks | 6 events |
| Sees | classic hooks, mcp__mermaid-c4-zoom__show_diagram calls |
| Draws on | Pane |
Is mermaid-c4-zoom safe to install?
mermaid-c4-zoom scores 84/100 on the MCPMods security check: Low risk. Things to review: starts processes outside the sandbox. 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 processes outside the sandbox | Review |
| Writes no files or config | Pass |
| Doesn't read environment variables | Pass |
| Only sees the events it hooks | Pass |
| 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.after | |
$.command.register | |
$.model.fork | drives Claude |
$.process.run | runs processes |
$.state.get | |
$.state.set | |
$.tool.register | drives Claude |
$.ui.close | draws interface |
$.ui.open | draws interface |
$.ui.panes | draws interface |
$.ui.resolve | draws interface |
$.ui.toast | draws interface |
How do I install mermaid-c4-zoom?
- 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/testy-cool/mermaid-c4-zoom claude plugin validate ./mermaid-c4-zoom/.
- Install it. Run this in your terminal, then /reload-plugins in an open session.
claude plugin marketplace add testy-cool/mermaid-c4-zoom && claude plugin install mermaid-c4-zoom@mermaid-c4-zoom
Or ask Claude to set it up
Paste this into Claude Code and it installs mermaid-c4-zoom for you:
Install the "mermaid-c4-zoom" Claude Code mod from https://github.com/testy-cool/mermaid-c4-zoom. Run claude plugin validate on it first and show me what it can access before you enable it.