RunMirror combines established ideas into a small agent-oriented reference implementation:
- VCR and record/replay testing tools demonstrate the value of cassettes at explicit I/O boundaries.
- OpenTelemetry provides broader tracing semantics. RunMirror is not an OpenTelemetry implementation; an export adapter is a possible extension.
- JSON Lines provides an append-friendly event representation.
- in-toto and DSSE motivate future signing adapters.
The testable hypothesis is that deterministic boundary cassettes make agent regressions easier to reproduce and review. The demo includes a seeded mismatch to prove first-divergence detection rather than showing only a passing replay.