🎨 pi-formatter

A pi extension that auto-formats files after every write and edit tool call.

The extension hooks into successful tool results, detects the file type, and runs the appropriate formatter. Failures never block the tool result, so formatting is always best-effort.

📦 Install

pi install npm:pi-formatter

⚙️ What it does

pi-formatter listens to successful write and edit tool calls and applies best-effort formatting. Formatter failures never block tool results.

Supported file types:

• C/C++
• CMake
• Markdown
• JSON
• Shell
• Python
• JavaScript/TypeScript

For JS/TS and JSON, project-configured tools are preferred first (Biome, ESLint), with Prettier as a fallback.

🔧 Configuration

Create <agent-dir>/formatter.json, where <agent-dir> is pi's agent config folder (default: ~/.pi/agent, overridable via PI_CODING_AGENT_DIR):

{
  "commandTimeoutMs": 10000,
  "hideCallSummariesInTui": false
}

• commandTimeoutMs: timeout (ms) per formatter command (default: 10000)
• hideCallSummariesInTui: hide formatter pass/fail summaries in the TUI (default: false)

🧩 Adding formatters

Each formatter is a runner that wraps a CLI tool behind a common interface. To add one:

1. Create a file in extensions/formatter/runners/ using defineRunner and a launcher helper (direct, pypi, or goTool).
2. Register it in extensions/formatter/runners/index.ts.
3. Add its id to a group in extensions/formatter/plan.ts.

The format plan maps file kinds to ordered runner groups. Each group runs in "all" mode (every runner) or "fallback" mode (first match wins).

📄 License

Apache-2.0