VIN Buyer Check

VIN Buyer Check is a single-page tool for private used-car buyers who want a quick reality check before trusting a seller description. A buyer enters a VIN and optional seller claims, and the app decodes the VIN through the official NHTSA vPIC API to show the confirmed year, make, model, trim, body class, engine, fuel, plant country, and decode warnings.

The tool then compares the decoded identity against the seller's claimed year, make, model, and trim. It highlights matches, mismatches, unknowns, and missing seller-provided details in buyer-readable language, so the user can ask better questions before paying for reports, inspections, travel, or the car itself.

The app also includes an intentionally honest pricing panel. NHTSA does not provide market valuation, so this version refuses to fabricate a dollar price range and instead clearly explains that a real pricing provider is needed for authoritative valuation. This keeps confirmed VIN facts separate from unsupported price claims.

Built as a Next.js App Router project with TypeScript, React, Tailwind CSS, a server-side lookup route, and Vitest coverage for VIN validation, NHTSA normalization, seller-claim comparison, pricing fallback behavior, and buyer-report composition.

Codex was used to guide the hackathon flow, produce the scope/PRD/spec/checklist, implement the app, resolve local Windows SSL setup issues, verify the build, deploy to Vercel, create the public GitHub repository, and prepare this Devpost submission.