Agents call tools. Postcondition checks whether the world changed.
This first public release provides:
- an MCP server, TypeScript SDK, and CLI backed by local SQLite
- constrained file, HTTP, Git, npm, and manual verifiers
- explicit satisfied, violated, and unknown verdicts
- evidence classes that never disguise self-attestation as external proof
- canonical evidence digests and a global hash-chained receipt ledger
- private-network blocking, bounded reads, fixed Git commands, and documented limitations
- 53 tests across SDK, CLI, real MCP stdio, persistence, integrity mutation, packaging, and network boundaries
- verified support for Node 20, 22, and 24
Install: npx -y postcondition-mcp serve
The security model is deliberately honest: local hash chaining detects mutation, but v0.1 does not claim external notarization or cryptographic non-repudiation.