FaultLine

AI-powered debugger and fault explainer for VS Code, Cursor, Windsurf, Antigravity IDE & VSCodium.
Understand terminal and task failures first. Optional sounds and notifications second.

What FaultLine is

First: a debugger and fault explainer. When a terminal command or task fails, FaultLine keeps the failure context and helps you understand it (including optional model-backed explanation when you ask).

Second: an error notifier. Optional sounds, status bar, toasts, webhooks, and Jira so you notice failures without staring at the panel.

Built by Anurag Mishra (4nur4gmishr4) for developers who ship.

Primary job: catch the fault and explain it

1. Detects failing terminals, tasks, and optionally diagnostics
2. Stores a sanitized copy of the last failure (command + output when available)
3. Opens Analyze Last Failure when you want a clear explanation and follow-up chat
4. Supports GitHub Copilot (no key) or other providers you configure
5. Redacts common secrets before any outbound explanation request

Secondary job: notify you

• Optional failure and success sounds
• Status bar + daily fail count
• Snooze, quiet hours, cooldowns
• Optional HTTPS webhooks and opt-in Jira

Auto-open of the analysis panel stays off by default. You choose when to open it.

Watch a failure get caught

How it works (3 steps)

What you get

Install

Marketplace

1. Open VS Code
2. Extensions, search FaultLine
3. Install

You will see FaultLine as the title. Under the hood the extension id is 4nur4gmishr4.fahh (kept stable so updates and download history stay on the same listing).

Marketplace page: FaultLine on Visual Studio Marketplace

Note: install from the GitHub Release VSIX below if the Marketplace page is not live yet in your region. The old “retired” badge was a shields.io false positive when the listing is empty — not the product status.

GitHub Release (VSIX)

1. Download fahh-3.5.2.vsix or faultline.vsix from Releases
2. Extensions view, menu, Install from VSIX…

Compatible IDEs

FaultLine uses standard VS Code Extension APIs and works natively on:

FaultLine uses extensionKind: ["workspace"] and standard APIs only, so it runs identically on any VS Code fork with engine ^1.93.0.

First install

On first install you see a short typed greeting from Anurag Mishra, then the welcome screen.
Press Skip anytime under the text to jump to the welcome screen.

Reopen later with FaultLine: Show Welcome Screen (no typing intro).

First setup

1. Command Palette
2. FaultLine: Open Configuration
3. Keep Copilot or pick a provider and save a key
4. Test a sound if you want notifications
5. Run a failing command, then FaultLine: Analyze Last Failure

Commands

Settings you will use most

Open FaultLine: Open Configuration, or search settings:

@ext:4nur4gmishr4.fahh

More options (quiet hours, sources, branch filters, allowlists) are in VS Code Settings via Open all FaultLine settings.

Privacy and safety

• Explanation auto-open is off. You open analysis when you want.
• API keys use VS Code SecretStorage.
• Common secrets are redacted before outbound explanation calls (best effort).
• Webhooks require https://. Private hosts need an allowlist.
• Jira is off until you enable it; Atlassian hosts only.
• Factory Reset deletes stored keys.

Details: SECURITY.md

What is new in 3.5.2

• Cross-IDE compatibility: Verified on VS Code, Cursor, Windsurf, Antigravity IDE, and VSCodium
• What's New popup: Clean update changelog shown on version upgrade
• 17 zero-bug fixes: AI provider mismatch, race conditions, audio fallbacks, ANSI stripping
• Open VSX ready: Publish to VSCodium/alternative registries with npm run publish:openvsx
• SEO hardened: Searchable across all VS Code-compatible IDE marketplaces

Full notes: CHANGELOG.md · Releases

For developers and contributors

Build, review, or extend FaultLine.

Architecture at a glance

Terminal / Task / Diagnostics
            |
            v
     FaultLineRuntime.handleFailure
            |
    +-------+--------+----------+----------+
    v       v        v          v          v
  Mute?   PII     History    Sound     Webhook
  Branch  sanitize (capped)  (optional) / Jira
  Ignore
            |
            v
     Explainer panel (on demand, or auto if enabled)

More detail: ARCHITECTURE.md

Local development

git clone https://github.com/4nur4gmishr4/vscode-FaultLine-Extension.git
cd vscode-FaultLine-Extension
npm ci
npm run vendor:sync
npm run lint
npm test -- --coverage
npm run compile

Press F5 for the Extension Development Host, or:

npm run package:prod

Contributing: CONTRIBUTING.md

Security notes for engineers

Report issues privately: SECURITY.md

Tests and CI

• Jest unit and integration smoke tests
• GitHub Actions on Windows, Linux, macOS
• Release workflow on v* tags packages the Marketplace VSIX (fahh-*.vsix)
• CodeQL and pinned TruffleHog

Project links

Media

Three animations in docs/media/:

Regenerate: npm run docs:gifs

FaultLine 3.5.2
AI-powered debugger and fault explainer first. Notifier second.
Works on VS Code, Cursor, Windsurf, Antigravity IDE & VSCodium.
Made by Anurag Mishra for developers everywhere · MIT