create-gsd-extension

<essential_principles>

Extensions are TypeScript modules that hook into GSD's runtime (built on pi). They export a default function receiving ExtensionAPI and use it to subscribe to events, register tools/commands/shortcuts, and interact with the session.

GSD extension paths:

• Global extensions: ~/.gsd/agent/extensions/*.ts or ~/.gsd/agent/extensions/*/index.ts
• Project-local extensions: .gsd/extensions/*.ts or .gsd/extensions/*/index.ts

The three primitives:

1. Events — Listen and react (pi.on("event", handler)). Can block tool calls, modify messages, inject context.
2. Tools — Give the LLM new abilities (pi.registerTool()). LLM calls them autonomously.
3. Commands — Give users slash commands (pi.registerCommand()). Users type /mycommand.