Core SDK

The Core SDK (front_end/core/sdk/) is DevTools' foundational data access layer wrapping the Chrome DevTools Protocol (CDP). It creates typed data access objects and models for CDP structures, abstracting away low-level JSON-RPC commands and events into developer-friendly APIs.

Architectural Principles

1. Single CDP Domain Responsibility

Each SDK model and data object encapsulates data and operations from a single CDP domain (e.g., DOM, CSS, Network, Debugger, Audits).

2. Cross-Domain Separation (What to Avoid)

Data from multiple CDP domains must be joined outside of core/sdk, typically in front_end/models/ (such as models/bindings/, models/issues_manager/, or models/trace/).

❌ Anti-pattern: Cross-domain getters on SDK objects

Do not add methods or getters to an SDK data object that fetch or resolve data from another CDP domain.

// ❌ BAD: DOMNode (DOM domain) must not reference Network or Audits domains directly.
class DOMNode {
  // Violates single-domain boundary:
  getNetworkRequest(): SDK.NetworkRequest.NetworkRequest|null {
    // ...
  }

  // Violates single-domain boundary:
  getIssues(): IssuesModel.Issue[] {
    // ...
  }
}

✅ Best Practice: Aggregate in models/

Keep DOMNode strictly focused on the DOM domain, and correlate cross-domain data in a higher-level model or service:

// ✅ GOOD: A higher-level model in models/ joins DOM and Audits/Network data.
// In front_end/models/issues_manager/ or similar:
const issues = issuesManager.issuesForNode(domNode);