@rolled-potatoes/opencode-mermaid

An OpenCode plugin that renders Mermaid diagrams in your browser.

Whenever the AI writes a mermaid code block, it automatically calls render_mermaid to open the diagram in your default browser. Multiple diagrams within the same session are accumulated in a single HTML file.

Install

Add the package name to the plugin array in your opencode.json:

{
  "plugin": ["@rolled-potatoes/opencode-mermaid"]
}

OpenCode will install it automatically on next start.

Features

• Opens diagrams in the browser via a local HTML file (/tmp/mermaid-<sessionID>.html)
• Accumulates all diagrams from a session in one file — just refresh the tab
• Collapsible source view for each diagram
• Cross-platform: macOS (open), Linux (xdg-open), Windows (start)
• Uses Mermaid.js v11 via CDN — no build step needed

Supported diagram types

flowchart, sequence, class, pie, gantt, state, ER, mindmap, timeline, git graph, and anything else Mermaid supports.

License

MIT