Failure Lab

Local chaos engineering for developers. Inject faults into HTTP traffic without touching your code.

What it does

Failure Lab runs a local proxy that intercepts HTTP requests and injects configurable faults — delays, errors, timeouts, and dropped connections. Use it to test how your application handles real-world network failures before they happen in production.

Features

• 6 fault types: Fixed Delay, Jitter, Fail Rate, Timeout, Status Override, Drop Connection
• Rule-based matching: Target specific hosts, paths, methods, and headers
• Quick presets: One-click fault scenarios (Slow Network, Service Outage, Flaky Errors, etc.)
• Live dashboard: Real-time stats, latency chart, and event log in the VS Code sidebar
• Auto-start: The Java core starts automatically when you open VS Code
• Import/Export: Share fault configurations with your team

How it works

1. Failure Lab starts a proxy on localhost:7777 and an API on localhost:7778
2. Point your application's HTTP client to use localhost:7777 as a proxy
3. Create rules in the sidebar to inject faults on matching requests
4. Toggle chaos on/off with a single click

Requirements

• Java 21+ (auto-detected from PATH, JAVA_HOME, or Gradle JDKs)
• The Failure Lab core JAR (included in the project, or auto-detected)

Fault Types

Extension Settings

Commands

• Failure Lab: Toggle Chaos — Enable/disable fault injection
• Failure Lab: Start/Stop/Restart Core — Manage the proxy process
• Failure Lab: Show Core Logs — View proxy output
• Failure Lab: Import/Export Rules — Share configurations