Compile feature requirements into paired architecture and behavior specs that check each other — CodeSpec beats Claude Code on FeatureBench

arXiv 2607.26777·medium signalXBlueskyLinkedInCopy link

Feature work in an existing repo fails differently from isolated code generation: agents produce designs with incomplete functional chains, where a behavior is implemented but never wired coherently across components. CodeSpec (July 29, 2026) links sub-requirement semantics to repository architecture to build explicit functional chains, then compiles them into two complementary executable specifications — one architectural, one behavioral — that jointly verify completeness and hold design-implementation consistency across long-horizon sessions. Reported pass rates on FeatureBench with DeepSeek-V4-Pro were 70.7%/55.0%/49.9% across its tiers, outperforming baselines including Claude Code, with generalization shown on NL2Repo-Bench.