API Access

Access to FMCSA API resources uses an API webkey for authentication. A webkey must be included as a query parameter in all API calls to successfully complete all transactions. To get a webkey, a user must have an active developer account. If you don't have one, please create an account first.
  1. Log in with Login.gov.
  2. Select My WebKeys, then click Get a new WebKey and fill out the form.
  3. The new WebKey will be displayed on screen.

Making API Calls

FMCSA resources for the most part follow REST protocol. To make API calls, please append your WebKey at the end of the URL using the query parameter
webKey=your_web_key
If an API request has a successful WebKey authentication, the resource server will provide responses with no additional steps from the requested. In the event there is a failure, an Authentication Failure JSON message will be returned. Please check the authentication key carefully and try again. If you have further authentication problems, please contact us by including your webkey information only. Please do not provide your client secret.
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