Proposal: Command Palette JS/TS Extensions

We have drafted a new specification for JavaScript and TypeScript extensions in Command Palette.

The goal is to expand CmdPal extension authoring beyond in-process WinRT/COM by enabling isolated Node.js-based extensions communicating with the host over JSON-RPC 2.0 via stdio.

This issue is intended to collect high-level feedback on the proposal and track follow-up work items.

Spec document:
CmdPal JSON-RPC Spec Overview (jsonrpc-spec branch)

What this proposal covers (high level)

• Per-extension process isolation (one Node.js process per extension)
• JSON-RPC 2.0 transport over stdio with LSP-style framing
• Type-safe TypeScript SDK surface aligned with CmdPal concepts
• Lifecycle model (discover, initialize, query, dispose, restart)
• Developer ergonomics such as hot-reload and debugger attach
• Support for core command/page/content scenarios expected from CmdPal extensions

Why this direction

• Improves accessibility for web developers (TypeScript, npm, Node.js ecosystem)
• Increases resilience through process isolation and crash containment
• Keeps host/extension boundaries explicit and protocol-driven
• Provides a scalable foundation for future extension capabilities

Out of scope for this initial spec

• WebView/browser-rendered extension UI
• Marketplace and auto-update infrastructure
• Full permission sandboxing model
• Non-JS language runtimes (for now)

Feedback requested

We would especially appreciate input on:

• API shape and ergonomics for extension developers
• JSON-RPC method boundaries and protocol design
• Extension lifecycle and failure handling behavior
• Manifest/schema expectations for packaging/discovery
• Security boundaries and permission model priorities
• Performance considerations for one-process-per-extension

Tracking and follow-ups

Please keep this thread focused on high-level spec feedback.

For implementation details, bugs, or discrete feature work, please open separate atomic issues and link them here so we can track progress cleanly.