Stop Trusting AI.
Start Trusting Proof.
Invariant runs your tests, captures screenshots, and generates verifiable proof that AI‑generated code actually works.
Three steps to proof
Define
Tell your AI agent what to build. It writes the test first — defining what "done" means — then implements the feature.
test('login works', async ({ page }) => {
await page.goto('/login');
await page.fill('[name="email"]', 'user@test.com');
await page.click('button[type="submit"]');
await expect(page).toHaveURL('/dashboard');
});Build
AI writes code while Invariant silently tracks every file edit. No extra steps — hooks capture it all automatically.
// Invariant tracks edits automatically → Edit 1: Create LoginForm component → Edit 2: Add /login API route → Edit 3: Wire form to API → Edit 4: Add session handling 4 edits tracked this session
Prove
Run one command. Get screenshots, test results, type checks, lint results, and visual regression — all in a proof report.
$ npx invariant run ✓ E2E Tests: 9/9 passed ✓ Type Check: clean ✓ Lint: clean ✓ Visual Regression: no changes ✓ Accessibility: 0 violations Proof generated. View: npx invariant dashboard
The Proof Stack
Every npx invariant run checks five verification layers
E2E Tests
Full Playwright browser tests verify your feature works end-to-end.
Type Check
TypeScript errors on changed lines are caught instantly. Pre-existing issues are just warnings.
Lint
Code quality issues on changed lines only — no noise from pre-existing debt.
Visual Regression
Automatic screenshot comparison catches unintended UI changes between runs.
Accessibility
WCAG compliance checks keep your app usable for everyone.
The Invariant Platform
A growing suite of tools for AI‑verified development. Your subscription covers everything.
Proof Runner
Run tests, capture artifacts, generate proof reports. The core of Invariant.
Code Reviewer
AI-powered code review with proof-based validation of suggestions.
Deploy Guard
Verify deployments work before they hit production. Automated smoke tests.
Most
developers don't fully trust AI‑generated code is functionally correct.
Invariant exists to change that.
Simple, transparent pricing
Free
For trying it out
- 3 full runs per day
- 1 project
- Cloud dashboard
- Auto-sync to cloud
- Screenshot capture
- Proof reports
Pro
14-day free trial
- Unlimited runs
- Everything in Free
- Unlimited projects
- Shared proof URLs
- All platform tools
- Priority support
Ready to prove your code works?
Set up in 2 minutes. Free forever for 3 runs a day.
npx @invariant-ai/cli init -y