WebContainer Failure Triage

Overview

This skill follows a deterministic diagnosis order: browser capability, served headers, lifecycle ownership, runtime events, process exit, dependency compatibility, and preview behavior. It avoids speculative retries and unsafe header weakening.

Prerequisites

• A reproducible URL or local command and the affected browser/version
• Permission to inspect application code, response headers, and bounded browser/runtime logs
• A synthetic reproduction when the failing project contains sensitive data

Tool Discipline

Use Read, Glob, and Grep to find boot calls, headers, runtime events, process handling, and dependency manifests. Use WebFetch only for current official StackBlitz or WebContainers documentation. Use Write or Edit only after the failing layer is identified; never retrieve secrets or full user projects for diagnosis.

Current Contract