Specification-Driven Development
🗒️ Description
A development methodology where detailed specifications are written before any code. The specs serve as the primary input for AI coding agents — the more precise and complete the spec, the better the agent output.
Also known as SDD (Specification-Driven Development). The OpenSpec framework formalizes this approach.
🧩 Key principles:
- Spec first, code second — never start coding without a spec
- Specs are the product — in Agentic Coding, the developer’s output IS the spec, not the code
- Executable specs — specs should be precise enough that an agent can implement them without ambiguity
- Iterative refinement — write spec → agent implements → review → refine spec → repeat
🔗 How it fits together
- Brainstorm — clarify what to build (goals, constraints, success criteria)
- Write spec — detailed design document with architecture, components, data flow
- Write plan — break spec into bite-sized implementation tasks
- Agent executes — AI coding agent implements task by task
- Review — human reviews each task output before proceeding
📖 Further reading
Agentic Coding Context Engineering
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