Cardog

# Cardog > The system of record for the Canadian vehicle. A typed graph of automotive > entities — every make, model, model year, recall and safety rating under a > permanent `{domain}:{key}` ref — served as a REST API with an error > contract designed for agents: an unknown ref is a 400 that names it and > suggests the nearest match, never a fuzzy guess or a silently empty result. The ref grammar is open source and free to hold: `npm install @cardog/entities` validates, builds and types refs offline with no API call and no key. ## Docs - [Full documentation](https://cardog.app/docs.md): every guide and the complete API reference as one markdown document — the one fetch that answers most questions. - [Changelog](https://cardog.app/changelog.md): what shipped, newest first, as one markdown document. - [Quickstart](https://cardog.app/docs/quickstart.md): Your first three calls: resolve free text to refs, then query with them. - [The Vehicle Graph](https://cardog.app/docs/vehicle-graph.md): The data model behind every endpoint: typed entities, permanent refs, and the grains that connect a VIN to specs, recalls, and the live market. - [The ref grammar](https://cardog.app/docs/ref-grammar.md): Hold the platform's identifier language offline: @cardog/entities validates, builds, and types refs with zero API calls — resolution is where the API begins. - [Authentication](https://cardog.app/docs/authentication.md): API keys, both accepted headers, and the plan limits — straight from the code. - [API conventions](https://cardog.app/docs/conventions.md): The mechanics every v2 group shares: encoding, response shape, null semantics, and the stability contract. - [Credits & limits](https://cardog.app/docs/credits.md): One commercial currency across the platform: per-family rates, plan allowances, live budget headers, and what happens at the edge. - [Errors](https://cardog.app/docs/errors.md): The v2 error envelope, every code, and why an unknown ref is always a name