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Dev tools · August 21, 2026

Invariant

Open-source business invariant engine for payment webhooks

What it does

Invariant is an open-source CLI engine that continuously tests Stripe & Razorpay webhooks against real-world edge cases (duplicate deliveries, out-of-order refunds, tampered HMAC signatures) and mathematically proves database state post-conditions in under 10 seconds. - 🔒 100% Offline & Private (localhost) - ⚡ Zero Telemetry & Instant Local Execution - 🛡️ Works with Node.js, Python, Go, Java, Ruby Try it: npx @yavona/invariant init

Contribute to yavonalabs/invariant development by creating an account on GitHub.

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