JavaScript SDK Guide

Use this guide when you are developing packages/client.

What this module owns

packages/client owns:

• MDP client registration and invocation handling
• websocket and HTTP loop client transports
• procedure registry behavior
• browser entry points and global bundle output

Build and test

Use the package-scoped commands first:

pnpm --filter @modeldriveprotocol/client build
pnpm --filter @modeldriveprotocol/client test

The build includes both TypeScript output and the browser bundle step from scripts/bundle.mjs.

Common development workflow

Typical loop:

1. update src/**
2. run pnpm --filter @modeldriveprotocol/client test
3. run pnpm --filter @modeldriveprotocol/client build
4. if browser-facing behavior changed, validate the downstream app that consumes it

Debugging expectations

This package is usually debugged in one of two ways:

• package-level tests for transport, registry, and invocation behavior
• downstream validation through the Chrome extension, VSCode extension, docs site, or smoke test

If the bug appears only in integration, expand to:

pnpm build
pnpm test

Common companion modules

• packages/protocol when message shape or guards need to move first
• apps/chrome-extension when browser bundle or client transport behavior breaks an extension flow
• apps/vscode-extension when extension-host embedding exposes the bug