grain-pi-compat 0.0.1-beta3

grain-pi-compat — run pi-style extensions on the grain runtime.

pi extensions are TypeScript / JavaScript files exporting a factory:

// <workspace>/.pi/extensions/my-tool.js
export default (pi) => {
  pi.registerTool({
    name: "shout",
    description: "Uppercases text",
    parameters: { type: "object", properties: { text: { type: "string" }}},
    execute: (args) => args.text.toUpperCase(),
  });
};

This crate adapts that shape to our [grain_script_boa::BoaExtension] by source-transforming each file: prepending a small shim that aliases pi's camelCase API onto grain's snake_case API, then — when an export default factory entry is present — wrapping the call to feed it the pi object. The transformed file is written to a temp dir, then BoaExtension::from_scripts_dir loads it.

What works in Phase 1

• pi.registerTool({ name, description, parameters, execute })
• export default (pi) => {...} factory entry
• Top-level pi.registerTool(...) (no factory) — also fine
• Discovery: <workspace>/.pi/extensions/*.js + ~/.pi/agent/extensions/*.js

Not yet (Phase 2+)

• pi.on(event, handler) event subscriptions
• pi.registerCommand / pi.registerShortcut
• ctx.ui.* interactive prompts
• TypeScript source via swc
• npm package extensions