Apply for partner access through the Carfax Business Development team at carfax.com/company/partners; Carfax API access requires a formal business agreement — there is no public self-service API or sandbox.
Once approved, obtain your API credentials and review the partner documentation; Carfax provides data feeds and integration APIs for dealer subscriptions, financial institution data products, and software platform integrations.
Authenticate API requests using the credentials specified in your partner agreement (typically an API key or OAuth 2.0 client credentials passed as a Bearer token).
To request a vehicle history report, submit the VIN to the Carfax report endpoint specified in your partner documentation; the response includes accident history, title events, odometer readings, service records, number of owners, and lemon law buyback flags.
Cache report responses with respect to your contract's terms on data freshness and re-query frequency; do not serve stale reports for high-stakes decisions such as loan origination or vehicle purchase.
For use cases where Carfax partnership is not feasible, implement the same integration pattern against an alternative provider (AutoCheck via Experian, VinAudit, or NMVTIS Title Check) that offers more accessible API access, while communicating clearly to users which data source is being used.
Known gotchas
Carfax data is partner-gated with negotiated per-report or subscription pricing; any open-source library claiming to expose Carfax report data is either scraping or using a reseller and likely violates Carfax terms of service.
Vehicle history reports are only as complete as the records reported to Carfax by participating dealerships, insurers, and state DMVs; a clean Carfax report does not guarantee a clean vehicle — disclaim this clearly in any consumer-facing integration.
NMVTIS (National Motor Vehicle Title Information System) is a federally mandated, lower-cost alternative for title-branded vehicle checks (salvage, theft, flood); it is accessible through approved data providers and is legally sufficient for many compliance use cases where a full Carfax report is not required.
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp