Convergence

The stage that happens after implementation and asks whether what was delivered does what the specification said. In GitHub's Spec Kit it is called converge and returns whatever is missing as new tasks; in the cycle Microsoft describes it is called validate and verifies that the output matches the spec.

It is not the same as cross-artifact analysis, which runs before any code exists and checks whether specification, plan and tasks agree with each other. One verifies documents against documents; the other verifies code against documents.

This is the stage that separates having a specification from holding anyone to it. Without convergence, the spec is a promise written at the start and forgotten at review — and most agent methodologies published up to 2026 added stages before the code was written without adding a single one after.