termaid plugin
termaid draws Mermaid diagrams right in Claude Code replies and in the terminal, 18 diagram types with no external dependencies.
- 579 ★ on the repository
- Last commit
- MIT
Extended access
Why this level
- The hook runs a local command on every Claude Code reply and changes terminal output.
Install
- Works in
In your terminal, with SkillFoxx CLI
npx skillfoxx add plugins/termaidDetects the agents on your machine, shows the access level and pins the version.
Other ways to install
Access and checks
How we reviewExtended accessThe tool runs code or makes network calls and only reads external data.
- The hook runs a local command on every Claude Code reply and changes terminal output.
This is third-party code. Review the repository files before installing.
What it does
termaid turns Mermaid blocks into diagrams made of terminal characters. The Claude Code plugin installs a `MessageDisplay` hook: `termaid --claude-hook` runs on every reply and Mermaid blocks render as drawings. The transcript keeps the Mermaid source, and if termaid fails Claude Code shows the original text. It bundles a `/termaid:mermaid` skill for explicit requests: render a file or the diagrams in a pull request description. There is also a CLI, a Python package, a Textual widget and Rich color output with 11 themes. Flowcharts, sequence, ER, state, Gantt, mindmap, kanban and more are supported.
Who it is for. Terminal developers who ask Claude Code to draw an architecture, migrations or order states and want to see the diagram at once.
Good fit when
- Claude Code explains an app architecture with a component diagram.
- A user login flow is shown as a sequence diagram.
- Database models are drawn as an ER diagram.
- A README or pull request description contains Mermaid blocks to view in the console.
- A diagram is embedded in a Python app or a Textual TUI.
Not a fit when
- A precise vector image for a document is needed: output is terminal characters.
- The terminal lacks box-drawing characters and the `--ascii` flag looks unsuitable.
- Claude Code is older than 2.1.275, where the plugin install command differs.
Example request
Draw a sequence diagram of a user logging in to this app and show where the session is checked.Limitations
The plugin calls the installed `termaid` command, which must be installed separately with `brew install termaid` or `uv tool install termaid`. The `/plugin install termaid --marketplace fasouto/termaid` command targets Claude Code 2.1.275 and newer; older versions need the marketplace added first. The hook changes only what the user sees, and the Mermaid source stays in the transcript. Wide diagrams are fitted to the terminal by tightening spacing and wrapping labels, so very large diagrams read worse.
How to disable. Run `/plugin uninstall termaid` or remove the `MessageDisplay` hook from `.claude/settings.json`. Remove the tool itself with `pip uninstall termaid` or `brew uninstall termaid`.
FAQ
Does Claude still see the Mermaid source?
Yes. The hook changes display only, and the transcript keeps the Mermaid code, so Claude keeps working with text.
What if I skip the plugin?
Add a `MessageDisplay` hook running `termaid --claude-hook` with a 10 second timeout to `.claude/settings.json`.
Can I render diagrams from a file?
Yes: `termaid diagram.mmd` for a file, `termaid --markdown README.md` for every Mermaid block in a document.
Are there dependencies?
The core has none: it is pure Python. Rich and Textual are optional extras.
Which themes exist?
Eleven themes with Rich installed: for example `neon` and `terra`, chosen with `--theme`. Without Rich the output stays uncolored.
Discussion
No questions or reviews yet.
Related
PluginsA Claude Code skill that builds diagrams of 23 types from a syntax reference bundled in the repository, called with /mermaid.
A Claude Code mod that colours terminal replies: tables, code, diagrams and charts in 16 themes with copy buttons.
Oh-my-mermaid
oh-my-mermaid
Turns a codebase into Mermaid architecture diagrams for Claude Code: the /omm-scan command and the omm view viewer. The README is in five languages
A skill that generates and renders Mermaid diagrams as SVG, PNG or ASCII: 15 themes and several diagram types, locally without a browser
The GitDiagram MCP and plugin give an agent the architecture map of a public GitHub repository with Mermaid source.
A file tree plugin for Claude Code that highlights the files the agent reads and edits, with git status, diffs and a preview
Comparison with similar tools
Cards that share the main search query, and how they differ.
| Tool | Official | Repository stars | Main difference |
|---|---|---|---|
| termaid (this card) | no | 579 | |
| mermaid-skill | no | 300 | teaches the agent to write Mermaid code; termaid renders finished blocks in the terminal and in Claude Code replies |
| Pretty Mermaid | no | 1,574 | turns Mermaid into polished images; termaid prints diagrams as characters straight in the console |
README in short
Mermaid diagrams render in the terminal, in Claude Code replies and in Python apps. The termaid.com page demonstrates it in a browser.