Show HN: Kavach – Replay production crashes locally without a DB or network

Category: devtools

Tags: deterministic-replay, debugging, crash-reproduction, agent-tooling, observability, mcp, invariants

Score: 7.8/10 (Innovation: 8, Technical: 9, Documentation: 8, Utility: 6)

Kavach is a deterministic flight recorder for backend services that captures every input, clock read, and random read, flushing a compact fixture on panic, error, or invariant violation. It then replays incidents byte-for-byte in microseconds with no database, broker, or network, and verifies fixes against perturbed incident variants to reject narrow patches. The 12-language SDK suite, MCP/agent integration, and formal journal spec make it a technically ambitious debugging and verification tool.

Target audience: backend devs, sre/devops, platform engineers

Repository: https://github.com/kavachlabs/kavach · Go · Apache-2.0

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