LemonFree API 2.0 Documentation

Last Updated: January 6, 2015


The Lemonfree API provides you with easy access to our vehicle listings and related data. This data is available through a simple and easy to use REST-based system, and returns fully valid XML or JSON results.


Requests to the Lemonfree API require an API key. This key consists of a string of letters and numbers which is unique to each developer, and allows us to track your usage. You can apply to obtain an API key; applications will be reviewed and the key will be activated if the review passes.

Output Formats

The default format for API responses is XML; however it's possible to obtain JSON instead by specifying a "format" parameter with a value of "json" (eg. &format=json)


The Lemonfree API uses per-user daily request quotas. Users are currently limited to 1000 daily requests per API key; each call to an API feed uses 1 request. All quotas are reset every day at 12 AM CST.


LemonFree currently provides 9 feeds for API users:

Submitting Leads

Qualified API accounts can allow their users to contact vehicle sellers by submitting leads through the API. If you have an API account and are interested in this feature, please contact us with a description of your use case.

Information for submitting leads.

Query Parameter Types

Type Query Field(s) Valid Values
Result Format format xml
Price price_min, price_max 0, 500, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, 20000, 22000, 24000, 25000, 26000, 28000, 30000, 35000, 40000, 50000, 60000, 70000, 80000, 90000, 100000, 9999999
Year year_from, year_to All years between 1900 and current year + 1 (i.e. 2016)
Mileage mileage_min, mileage_max 0, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, 100000, 110000, 120000, 130000, 140000, 150000, 160000, 170000, 180000, 190000, 200000, 500000, 9999999
State state Two character state / provincial abbreviation
List of U.S. State Abbreviations
List of Canadian Provincial Abbreviations
Country country us
Sort sort_by, sort_dir count, price, mileage
asc, desc

Query Results

All feed results have the same basic structure, making it much less time consuming to use multiple feeds in your application. Here is a list of the common fields found in all results:

Field Description
request_type The type of request (or feed) that was made to obtain these results
request_params All request params that was associated with the request
response_code The status of the response. See Response Codes
result A container for the individual result items
response_messages Any messages associated with the response. Typically messages will be error messages.

Response Codes

Every result returned will have a response code field. The following is a list of possible response codes.

Code Error Message Description
0 none This code indicates that the request was successful, and the response should contain valid results.
1 Invalid API key The API key specified in the request either does not exist, or the account it belongs to hasn't yet been validated.
2 Maximum daily quota reached The daily request quota associated with this API key has been reached
3 No data available The request made did not return any results
4 API service unavailable There was a problem communicating with the API server; usually only occurs if the API is undergoing maintenance.
5 Required parameters missing Some of the required parameters for the feed are not present
6 Not authorized The API key specified in the request is not authorized for this particular request
8 Submitted lead rejected The lead submitted has been rejected; view message in response for rejection reason
10 Maximum lead submission daily quota reached The daily lead submission quota associated with this API key has been reached