For Agents
Search used and new vehicle listings in the US, Canada, and UK, decode VINs, get price predictions with comparables, check listing history and recalls, and look up dealers.
Use for: Find used Toyota Camry listings within 50 miles of zip 30301, Decode VIN 1HGCM82633A004352 into its trim and options, What is a fair price for this 2019 Honda Civic with 40,000 miles?, Get the listing history for a VIN before I buy
Not supported: Does not process vehicle purchases, auto loans, or insurance quotes. Use for automotive listings, VIN decoding, vehicle history, and market pricing data only.
The MarketCheck Automotive Data API searches live and historical vehicle listings across North America and the UK and decodes VINs into build specs. Inventory search covers cars, motorcycles, RVs, and heavy equipment from dealers, auctions, and private sellers, filtered by make, model, year, zip, radius, price_range, and miles_range. It also returns per-VIN listing history and recalls, MarketCheck Price predictions with comparables for the US, UK, and Canada, market days supply, inferred sales stats, OEM incentives, dealer search, and batch jobs for NeoVIN decoding and MarketMatch ranking.
Install Jentic One Beta
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the MarketCheck Automotive Data API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fmarketcheck.com%2Fmarketcheck" | shStep 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fmarketcheck.com%2Fmarketcheck" | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
What an agent can do with MarketCheck Automotive Data API.
Search active car inventory by make, model, year, zip, and radius, with price_range and miles_range filters and start/rows pagination
Decode a VIN into specs with the basic, enhanced, or NeoVIN decoder, including available options packages
Predict a vehicle's MarketCheck Price from vin, miles, and dealer_type, with comparables, for the US, UK, or Canada
Pull the listing history for a VIN, or by VRM in the UK, and check open recalls through AutoRecalls
Measure market days supply and inferred sales stats for a make, model, or VIN in a state or city
Find dealers and dealerships near a location and read a dealer's details by dealer_id
Submit batch NeoVIN decode and MarketMatch ranking jobs, poll their status, and download the results
Patterns agents use MarketCheck Automotive Data API for, with concrete tasks.
★ Car-shopping agent through Jentic
A buyer's assistant searches inventory, checks a candidate car's history and recalls, and compares its asking price with a predicted market price. Through Jentic it calls the MarketCheck search, history, recall, and price operations, and the api_key query parameter is added by Jentic at call time so the agent never holds it.
GET /search/car/active with make 'Toyota', model 'Camry', zip '30301', radius 50, and rows 10, then for the first listing call GET /history/car/{vin} and GET /car/autorecalls/{vin}
Dealer appraisal and pricing
Dealers pricing a trade-in need a market-based number. The MarketCheck Price operation takes vin, miles, and dealer_type, with optional zip, city, and state, and a comparables variant returns the listings behind the estimate, so the appraiser can show how the price was reached.
GET /predict/car/us/marketcheck_price/comparables with vin '1HGCM82633A004352', miles 85000, dealer_type 'franchise', and zip '30301', then report the predicted price and three comparables
VIN decoding for vehicle records
Insurance, finance, and fleet systems store a VIN and need the build details behind it. The basic, enhanced, and NeoVIN decoders return specs, and NeoVIN also lists options packages. For large files, the NeoVIN batch job accepts a submission, reports status, and serves the results for download.
GET /decode/car/neovin/{vin}/specs and GET /decode/car/neovin/{vin}/options-packages for VIN '1HGCM82633A004352', then merge the trim and installed packages into one record
Market supply and demand analysis
Inventory planners compare how fast vehicles sell in a region. Market days supply measures how many days of inventory sit on the market for a set of filters such as make, model, and state, and inferred sales stats summarise sales by make, model, or year-make-model in a state or city, which helps decide what to stock.
GET /mds/car with make 'Ford', model 'F-150', and state 'TX', then GET /sales/car with ymm '2021|ford|f-150' and state 'TX', and compare supply with sales
73 endpoints — the marketcheck automotive data api searches live and historical vehicle listings across north america and the uk and decodes vins into build specs.
METHOD
PATH
DESCRIPTION
/search/car/active
Search active car inventory
/listing/car/{listing_id}
Get car listing details
/decode/car/neovin/{vin}/specs
Decode a VIN with NeoVIN
/predict/car/us/marketcheck_price
Predict a US vehicle price
/history/car/{vin}
Listing history by VIN
/car/autorecalls/{vin}
Recalls for a VIN
/mds/car
Market days supply
/dealers/car
Search car dealers
/search/car/active
Search active car inventory
/listing/car/{listing_id}
Get car listing details
/decode/car/neovin/{vin}/specs
Decode a VIN with NeoVIN
/predict/car/us/marketcheck_price
Predict a US vehicle price
/history/car/{vin}
Listing history by VIN
/car/autorecalls/{vin}
Recalls for a VIN
/mds/car
Market days supply
/dealers/car
Search car dealers
This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use.
Base layer of spec validity and structural soundness.
Aggregated quality score from linter diagnostics, weighted by severity.
Percentage of `$ref` references that resolve successfully.
Checks whether the API description parses successfully and conforms to its declared specification (e.g., OpenAPI).
Structural correctness score based on schema issues using logarithmic dampening.
Clarity, completeness, and ingestion readiness for developers and tooling.
How richly the API is illustrated with examples.
Percentage of examples that conform to their schemas.
Percentage of operations with complete response definitions (success, client error, server error).
Health of API ingestion, bundling, and resolution within Jentic pipelines.
Semantic breadth, depth, and agent comprehension for AI systems.
Coverage of descriptions across API elements.
Coverage of RFC 9457 Problem Details for error responses.
Coverage, uniqueness, and casing consistency of operationIds for AI inference.
Coverage of summaries across operations/tags/info.
Functional utility, complexity comfort, and AI orchestration readiness.
Agent comfort level based on API operational and structural complexity.
Trust, risk posture, and security compliance.
Average quality of security schemes based on authentication method strength (weakest link for OAuth2).
Findability, semantic richness, and reasoning readiness.
Clarity and depth of descriptions across API elements.
Score it yourself
Every API in the directory is allowlisted, so you can re-score it with no key required.
npx @jentic/api-scorecard-cli score <openapi-url>What agents get from Jentic-routed access to this vendor.
Setup
Wiring MarketCheck by hand means appending its api_key query parameter to every call, paging with start and rows, and treating 422 at the deep-pagination limit as the end of results. Through Jentic you install once, import the MarketCheck API from the API Directory, store the key once, and your agent calls it.
Permission scoping
Most MarketCheck searches take their filters as query parameters, so rules bound which operations your agent may call rather than which vehicles. Limit the agent to the operations it needs, such as inventory search and price prediction, and leave batch jobs and AAMVA report generation out unless you add them.
Credential isolation
Your MarketCheck key is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'search used car listings' or 'decode a VIN', and Jentic returns the matching MarketCheck operation with its input schema so the agent picks the right one of its 73 endpoints without browsing the reference docs.
Alternatives and complements available in the Jentic catalogue.
Specific to using MarketCheck Automotive Data API through Jentic.
Is there a MarketCheck MCP server?
MarketCheck's spec points to a docs MCP server for its documentation. To let your agent call the data API itself, you don't need an MCP server: Jentic connects it directly from the API Directory. Import it, store your credential once, and your agent finds the operation it needs by intent, without loading tool definitions for all 73 endpoints into its context.
What authentication does the MarketCheck Automotive Data API use?
Per its OpenAPI spec, the MarketCheck API takes your key as the api_key query parameter, not a header. Keys come from the MarketCheck developer portal. Through Jentic the key is stored encrypted by your own Jentic One instance and added to the request at call time, so it never appears in the agent's prompt or logged URLs.
What are the rate limits for the MarketCheck Automotive Data API?
The spec lists Free at 500 calls/month and 5 rps, Basic at 5,000/month and 5 rps, Standard pay-as-you-go at 40 rps, and Enterprise as custom. Throttled calls return 429 with Retry-After and RateLimit and Quota headers. Paging past your plan's deep-pagination limit returns 422, which marks the end of results rather than a retryable error.
Can I search vehicles other than cars with the MarketCheck API?
Yes. Besides cars, the spec has inventory search and listing details for motorcycles, RVs, and heavy equipment, plus auction and private-party (FSBO) car search. UK search covers cars and RVs.
Can I limit what my agent is allowed to do with the MarketCheck Automotive Data API?
Yes. Write a rule that allows only GET /search/car/active, GET /listing/car/{listing_id}, and GET /predict/car/us/marketcheck_price, so a shopping agent can search and price cars without spending your quota on batch jobs or AAMVA report generation. Your own instance runs those calls.
How do I search used car listings through Jentic?
Add the MarketCheck Automotive Data API to Jentic One from the directory and store your api_key once. Your agent searches for 'search used car listings near a zip code', calls GET /search/car/active with make, model, zip, and radius, and pages with start and rows (rows max 50). To run it on your own infrastructure, install Jentic One from its GitHub repo.
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