# Deterministic Transformation **Domain:** Functional Design / Reproducibility **Doc Type:** Canonical Concept Node **Maturity:** Core Design Principle **Related:** [[wiki/Portable Contract|Portable Contract]], [[wiki/Normalized Output|Normalized Output]], [[wiki/Derived Artifact|Derived Artifact]] --- ## Definition **A deterministic transformation produces the same normalized result from the same normalized input and contract version.** It excludes hidden time, randomness, mutable global state, and host-specific interpretation unless those values are supplied explicitly. ## Project Context Slug creation, text cleanup, quote extraction, path normalization, serialization, and identifier construction should be deterministic core capabilities. Host effects such as writing files or updating an editor remain separate operations. ## Key Insight **Determinism makes regeneration safe, fixtures meaningful, and cross-runtime disagreement detectable.** ## See Also [[wiki/Shared Fixtures|Shared Fixtures]], [[wiki/Host Adapter|Host Adapter]], [[wiki/Rebuildable Projection|Rebuildable Projection]], [[wiki/Technical Terms|Technical Terms]]