Ouroboros formalizes spec-first agent work with numeric gates.

Q00/ouroboros (5,165 stars, +196 this week) replaces prompting with a five-phase loop: interview → seed → execute → evaluate → evolve (GitHub). What separates it from other spec-driven tooling is that the gates are numbers. Socratic questioning must drive an ambiguity score to ≤0.2 before proceeding, and the evolve loop runs until ontology similarity converges at ≥0.95. The YAML seed spec is immutable once crystallized, execution uses Double Diamond decomposition, evaluation is a three-stage gate of mechanical → semantic → multi-model consensus. Nine reasoning modes across nine backends.