MarketCheck Cars API vs Kelley Blue Book for AI agents
MarketCheck Cars API is a paid REST API of new, used and certified car listings collected from dealer and other source websites, plus dealer, VIN and market-statistics endpoints. Kelley Blue Book is a licensed REST service for Kelley Blue Book vehicle values and VIN decoding; it does not list cars for sale.
The short answer
- MarketCheck Cars API: Searching current US dealer inventory at scale with price, mileage, photos and a link back to the dealer's listing page.
- Kelley Blue Book: Businesses that need licensed Kelley Blue Book values inside their own systems, not listing search.
Side by side
| MarketCheck Cars API | Kelley Blue Book | |
|---|---|---|
| Searches | Active new, used and certified dealer listings in the US, recent dealer inventory (last 90 days) in the US and Canada, private-party and auction listings, and dealers by location. | Vehicle values by VIN or configuration (year, make, model, trim, options, mileage) and ZIP code. |
| Returns | Listing records with price, miles, seller name, seller type, photo URLs and a link to the original vehicle details page, plus specs and dealer details. | New and used values such as fair purchase price, private party, trade-in, auction and lending values, plus ratings and reviews. |
| Before the first call | A MarketCheck developer account and API key from the Developers Portal. | A signed data license with Cox Automotive (Master Data License plus product terms), arranged through a contact form. |
| Free | Free plan at $0 a month with 500 calls a month and a 100-mile search radius limit. | – |
| Paid | Basic plan $299 a month plus per-call data fees (inventory search is $0.002 a call). | – |
| Acting on a result | Each listing carries the seller name and a link (vdp_url) to the vehicle details page on the source site; no dealer phone field is defined in the data definitions. | – |
| Limits on keeping or showing results | No caching, storing, indexing or persisting of substantial portions of the data; no independent or persistent datasets outside the service. | Industry internal-use terms allow internal use only: no sharing with third parties, no posting on public websites, no modifying the data, and a KBB copyright notice must accompany it. |
| AI in its terms | Data may not be used to train, fine-tune or improve generalized ML or AI models, but may be used inside AI applications when accessed in real time. | – |
| Coverage | United States for active inventory search; US and Canada for recent dealer, private-party and auction inventory; the MCP docs also list the UK. | United States. |
| MCP server | Official hosted MCP server at https://api.marketcheck.com/mcp?api_key=YOUR_API_KEY (needs an API key; covers US, Canada and UK). | – |
Where Openpath fits
Openpath has no car listings yet. Cars are on its roadmap, from sellers and dealers who list them themselves. Get listed.
Questions people ask
What do I need before I can use MarketCheck Cars API?
A MarketCheck developer account and API key from the Developers Portal.
Is MarketCheck Cars API free?
Free plan at $0 a month with 500 calls a month and a 100-mile search radius limit.
Sources
Every line about another company comes from its own pages. Prices and terms change, so check the source before you rely on one.
MarketCheck Cars API, read on October 15, 2026:
- marketcheck.com/apis/pricing: “$0 /mo ... 500 calls per month”
- marketcheck.com/apis/pricing: “100 mile radius restriction”
- marketcheck.com/apis/pricing: “$299 /mo + data fee”
- marketcheck.com/apis/pricing: “$0.002”
- marketcheck.com/apis/cars: “Lookup New / Used / Certified cars for sale in US”
- marketcheck.com/apis/cars: “New / Used dealer cars for sale in US & Canada from last 90 days”
- docs.marketcheck.com/docs/guides/data/cars/inventory/data-definitions: “The URL of the Vehicle Details Page (VDP)”
- docs.marketcheck.com/docs/guides/data/cars/inventory/data-definitions: “The name of the dealership or seller, as displayed on the source website.”
- docs.marketcheck.com/docs/guides/data/cars/inventory/data-definitions: “The name of the source website from which the vehicle listing was scraped.”
- docs.marketcheck.com/docs/get-started/api/mcp/getting-started.md: “https://api.marketcheck.com/mcp?api_key=YOUR_API_KEY”
- marketcheck.com/terms_of_service: “Cache, store, index, or otherwise persist substantial portions of data obtained through the Service”
- marketcheck.com/terms_of_service: “Use MarketCheck data to train, fine-tune, or improve any generalized machine learning or artificial intelligence models”
- marketcheck.com/terms_of_service: “You may use MarketCheck data within applications that utilize AI models, provided the data is accessed in real time”
Kelley Blue Book, read on October 15, 2026:
- b2b.kbb.com/industry-solutions/info-driver-web-service-idws: “Provide your clients access to the industry relevant valuations they require with InfoDriver℠ Web Service (IDWS).”
- b2b.kbb.com/industry-solutions/info-driver-web-service-idws: “Integrate Kelley Blue Book Values into your system or application”
- coxautoinc.com/terms/wp-content/uploads/sites/3/Kelley-Blue-Book-InfoDriver%E2%80%93Industry-Internal-Use-Additional-Terms.pdf: “Licensee may use InfoDriver and the Licensed Data only for internal use”
- coxautoinc.com/terms/wp-content/uploads/sites/3/Kelley-Blue-Book-InfoDriver%E2%80%93Industry-Internal-Use-Additional-Terms.pdf: “post or otherwise make accessible any Licensed Data on any website”
- coxautoinc.com/terms/wp-content/uploads/sites/3/Kelley-Blue-Book-InfoDriver%E2%80%93Industry-Internal-Use-Additional-Terms.pdf: “for a specific vehicle identified by a VIN or configuration (i.e.: year, make, model, trim, optional equipment, and mileage)”