What Is Spec-Driven Development? The Spec as Source of Truth
For most of software history the spec was a temporary planning artifact and the code was ground truth. Spec-driven development inverts that: the versioned specification becomes the primary artifact, and code is generated or verified against it. The idea is old — formal methods, design-by-contract, BDD all contain versions. What’s new is the motive: AI agents need explicit, durable intent because prompts evaporate and sessions reset.