Fulfillment URL failure in SaaS marketplace

When publishing a SaaS product in AWS Marketplace, the fulfillment URL is where customers are redirected after subscribing to your product. This redirect is specifically a POST request that includes a temporary token valid for 4 hours.

For your fulfillment URL to work properly, it must meet several requirements:

1. Correct URL format: The URL must begin with 'https://' or 'http://' and follow proper formatting standards.

2. HTTP status code validation: Your fulfillment URL must return an HTTP status code of 200. If it returns any other status code, you'll receive an error indicating that you need to provide a fulfillment URL that renders with a 200 status code.

3. Accessibility: The URL must be publicly accessible and properly configured to handle the POST request from AWS Marketplace.

Since your URL works after a refresh but not on the initial redirect, this suggests your landing page may not be properly handling the POST request that AWS Marketplace sends. The initial redirect includes a temporary token (regToken) that your application needs to exchange for a customer ID by calling the ResolveCustomer API in the AWS Marketplace Metering Service.

I recommend:

• Testing your fulfillment endpoint thoroughly before submission to ensure it properly handles POST requests
• Verifying that your landing page correctly processes the token parameter on the initial POST request. Configure the page to accept and process the x-amzn-marketplace-token.
• Ensuring your endpoint returns a 200 status code immediately upon receiving the redirect

The fulfillment URL setup is a critical part of the SaaS integration process, as it's the entry point for customer verification and entitlement checking.
Sources
Troubleshooting SaaS products - AWS Marketplace
Work with SaaS products using the AWS Marketplace APIs - AWS Marketplace
Step-by-Step Guide to SaaS Integration with AWS Marketplace | AWS Marketplace
How to launch a SaaS product in AWS Marketplace | AWS Marketplace