Urdr is a Shen-governed deterministic laboratory for whole distributed systems. Its first target is a complete k3s cluster inside a controlled Firecracker microVM, with deterministic logical time, network delivery, entropy, external-service replay, fault exploration, snapshots, and failure shrinking.
The authoritative design is in SPEC.md.
- Portable Shen world kernel and scenario/property language
- Cross-runtime semantic agreement through Bifrost
- Firecracker/KVM execution on Linux x86-64 and ARM64
- Custom single-vCPU Linux guest with deterministic clock and entropy devices
- Packet-level broker plus OpenResty/Shen-Lua service models
- Seeded exploration, exact decision replay, and snapshot-aware shrinking
- Explicit determinism certificates that fail closed on uncontrolled inputs
Urdr is currently at the specification stage.
Urdr is licensed under the Apache License 2.0.