Authentication

The ATC Taxes & Fees API uses token-based authentication. You must include your authentication token in the request header for all fee quote requests.

Note: ZIP code lookup endpoints (zipcodeinfo, isinstate) do not require authentication.

Request Header

Include the userToken header in your POST requests:

Header Name	Type	Required	Description
`userToken`	String	Yes (for POST)	Your API authentication token provided by ATC
`Content-Type`	String	Yes	Must be `application/xml`

Example Request Headers

# HTTP Headers for Fee Quote Request
POST https://svc.autotitling.com/AGFService/v3.0/
Content-Type: application/xml
Content-Length: 1772
Host: svc.autotitling.com
userToken: YOUR_TOKEN_HERE
            

Security Warning: Keep your API token confidential. Do not expose it in client-side code, public repositories, or logs.

Obtaining API Credentials

To obtain your API token, please contact the ATC API Support team:

Email: api@autotitling.com

What You'll Receive

Your unique userToken for API authentication
XSD schema definitions (upon request) for request/response validation
Access to the production API endpoint

JSONP Support (Web Applications)

For web applications that need to avoid cross-domain security issues, the API supports JSONP via GET requests.

JSONP Request Format

Instead of sending an XML POST, you can use a GET request with the following parameters:

Parameter	Description
`callback`	Your JavaScript callback function name
`request`	URL-encoded XML request payload

# JSONP GET Request Example
GET https://svc.autotitling.com/AGFService/v3.0/?callback=myCallback&request=<encoded_xml>
            

Tip: JSONP allows web applications to make cross-domain requests without requiring a proxy service.

Base URL

Environment	Base URL
Production	`https://svc.autotitling.com/AGFService/v3.0/`