Overview

Implement a WebSocket client that speaks Chrome DevTools Protocol JSON-RPC.

Tasks

• Implement WebSocket connection to Chrome CDP endpoint (ws://host:port/devtools/browser/...)
• JSON-RPC message framing: {id, method, params} → {id, result} / {id, error}
• Async event handling for CDP events (e.g., Page.loadEventFired)
• Auto-incrementing message IDs (atomic counter)
• Pending response map: AutoHashMap(u32, *ResponsePromise)
• Connection lifecycle: connect, reconnect, close
• CDP domain helpers: Page.navigate, Runtime.evaluate, DOM.getDocument, Accessibility.getFullAXTree

Reference

• Pinchtab uses Go's chromedp library wrapping CDP
• We implement raw CDP over WebSocket for zero-overhead

Acceptance Criteria

• Can connect to a running Chrome instance
• Can send Target.getTargets and parse response
• Can navigate to a URL and wait for load
• Unit tests with mock WebSocket server