Parity

In modern software engineering, code moves fast while API documentation lags behind. Developers refactor endpoints, rename payload parameters, update status codes, or change authentication schemes, but updating Markdown documentation is routinely forgotten. This documentation drift causes silent runtime failures, broken client SDKs, integration roadblocks, and wasted engineering hours debugging unannounced 400 Bad Request or 401 Unauthorized errors. Traditional manual pull request reviews routinely miss subtle schema and parameter renames. Parity is an automated, evidence-backed API documentation drift engine. Instead of relying on non-deterministic guesses, Parity performs static verification between source code and Markdown documentation. It crawls repositories, parses routes using syntax-aware brace-counting AST extractors, extracts contract promises from documentation, and cross-compares endpoints, parameters, authentication schemes, and responses. When drift is detected, Parity outputs line-level evidence citations and unified diff patches, verifying that zero drifts remain after application. Parity is built for backend developers, API platform leads, technical writers, and developer advocates. Through a clean web interface, users can inspect an instant local sandbox demo or provide a public GitHub repository URL with target documentation and code paths across specific files or entire directories. Parity crawls and scores files, extracts contracts, and streams a live execution log alongside an interactive repository map. Users inspect discovered mismatches with side-by-side evidence cards showing exact file paths, line numbers, and extraction provenance badges. In the sandbox demo, users can simulate fixes in-memory with verified zero-drift results, while public repository audits remain strictly read-only to safeguard external codebases. What sets Parity apart is its strict determinism-first philosophy. Code AST analysis and drift matching are entirely mathematical and rule-based, guaranteeing zero false passes or hallucinations. Generative AI is strictly isolated as a targeted fallback to parse unstructured human sentences only when documentation lacks tables or code blocks. Running purely statically without starting servers or executing untrusted code, Parity audits repositories in milliseconds, eliminating manual documentation review toil and keeping release pipelines green.