Built this after one too many production incidents caused by a renamed variable or missing key that CI never caught. EnvSentinel treats your .env as a versioned contract - you define the rules once in a JSON schema, then validate against it in CI, pre-commit, or locally. Also regenerates .env.example from the contract automatically so it never drifts. Pure Python stdlib, no external dependencies, 3.10+.
Show HN: EnvSentinel – contract-driven .env validation, zero dependencies | Heykuki News