v1.1.1 FROZEN Proprietary Pre-Acquisition Not affiliated with Railway

Blue/green semantics for workloads that own local state

A general-purpose state lifecycle engine: mutation journals, bounded cutover, portable State Archives, fire drills, and verified recovery — for arbitrary volume-backed workloads, not only databases.

Open live demo Proof GIFs Railway fit
Railway already provides volumes, backups, Postgres PITR, logical dumps, and live resize. SDE addresses generic filesystem state mobility, deployment-safe cutover, and ENGINE_PROVIDED archives that remain usable after a source environment disappears.

See it run

Cutover pipeline demo GIF
Transactional cutover · freezes on COMMIT
CLI doctor demo GIF
CLI proof · freezes on readiness

Measured local cutover: barrier ~16 ms · write pause ~15 ms · 129 mutations. Proof pack →

Evaluate locally

One command builds, tests, migrates, restores, and writes receipts.

.\evaluate.ps1
# or: bash ./evaluate.sh

Embed

CLI · LIBRARY · CONTROL-PLANE modes. Versioned events for platform integration.

Repository · docs in-tree under docs/

Architecture at a glance

ACTIVE ──checkpoint──▶ SHADOW
   │                      │
 journal ◀────────── continuous replay
   │                      │
   └── barrier → final Δ → verify → cutover → observe → COMMIT
                              │
                     ENGINE_PROVIDED PSA → escrow / clone / fire-drill