Is there a free API source for nationwide car inventory? Furthermore, is there an API for the lease math numbers like MF and residual based on make and zip code that is free? Would love to try and build something to help people automate this task a bit. Thanks in advance!
Maybe start with a search? This has been discussed multiple times.
My paid AI said this:
The short answer is no. There is currently no truly free, comprehensive nationwide vehicle inventory API, and there is no free API for lease money factors (MF) and residual values. Those datasets have significant commercial value and are generally licensed.
Here’s how the landscape breaks down.
1. Nationwide vehicle inventory
Free-ish options
- Edmunds API (limited/partner access)
- Dealer inventory
- Vehicle specs
- Dealer information
- Inventory search
- Not a public unlimited free API anymore.
- NHTSA vPIC
- Completely free
- VIN decoding only
- No inventory
- No pricing
- No dealer listings
- CarQuery API
- Free
- Vehicle makes/models/specifications
- No dealer inventory
Commercial APIs
These are what most automotive websites use:
- Marketcheck
- Cars.com
- Edmunds
- AutoTrader
- Cox Automotive
- DataOne
- ChromeData
These typically cost anywhere from $100/month to several thousand dollars per month, depending on API calls and licensing.
2. Lease Money Factor and Residual APIs
This is even more restrictive.
These values come from:
- BMW Financial Services
- Lexus Financial
- Ford Credit
- Ally
- GM Financial
- etc.
The banks consider these proprietary.
There is no public API where you can simply ask:
BMW X3 M50
92677
36 months
10k miles
→ MF = .00178
→ Residual = 58%
That API doesn’t exist publicly.
Where lease numbers come from
Most websites obtain them by one of these methods:
- Manufacturer/dealer portals
- Dealer Management Systems (DMS)
- Manual entry every month
- Data sharing agreements
For example, Leasehackr’s widely used lease calculator relies on community-sourced and manually updated data rather than a free official API.
3. OEM incentive APIs
One area that does exist commercially is incentives.
Marketcheck, for example, offers APIs for:
- cash rebates
- loyalty incentives
- conquest programs
- lease specials
- APR programs
- ZIP-code-specific incentives
These are paid services.
If you’re building something like Leasehackr or a broker site
Most implementations look something like:
Inventory
↓
Marketcheck API
Vehicle Specs
↓
NHTSA + CarQuery
Dealer Locations
↓
Google Places
Lease Program
↓
Manual monthly upload
Lease Calculator
↓
Your own math
The lease calculation itself is straightforward once you have the inputs:
- MSRP
- Selling price
- Residual %
- Money factor
- Incentives
- Fees
- Taxes
The hard part is obtaining the current MF and residual values, not performing the calculation.
If I were building a free version today
I’d use:
- NHTSA vPIC for VIN decoding (free)
- CarQuery for vehicle specifications (free)
- Manufacturer inventory search pages or dealer websites (scraped, where permitted by their terms) for inventory
- User-submitted or manually maintained monthly lease program data for MF and residuals
That combination keeps infrastructure costs very low while still delivering a useful experience.
No. Nothing’s that free and accurate across all manufacturers.
Not free. Even Edmund’s doesn’t post all their numbers publicly due to licensing/usage restrictions.
All this data is privileged and provides competitive advantages. Previous posts on LH have also noted that banks even delay publishing in order to view their competitor’s numbers first.