Spec-Driven Development in 2026: What It Is, the Tooling, and How Teams Actually Use It (opens in new tab)

A field guide to the practice that's reshaping how software gets built with AI agents. TL;DR — Spec-Driven Development (SDD) makes a precise, executable specification the source of truth and treats code as a generated, verifiable artifact. The spec declares intent; the code realizes it. In 2026 it went mainstream because AI agents are great at writing code and terrible at guessing what you meant. Jump to: Why now · Specs vs. executable specs · Maturity model · Workflow · Tooling · EARS · Work...