SMRFORGE takes a small modular reactor from concept to a full-core design, safety numbers, and cost — in one auditable run. Screen fast in pure Python, escalate the same inputs to OpenMC for reference accuracy, and ship every result as a verifiable evidence bundle. Reference-validated: the full-core nodal engine closes the analytic IAEA-2D PWR benchmark to +19 pcm. Community MIT; Pro FSL-1.1-MIT. Air-gap-safe.