AdServer URLs

In this video we show you, how the ad server configuration uses data in the url you send to our system when requesting a VAST document.

Welcome back to another RabbitStream tutorial! Today, we’ll delve into the theoretical intricacies of URLs and demystify the magic that occurs when crafting ad server configurations. To follow along effectively, it’s beneficial to have a basic understanding of ad server configurations and perhaps even our previous tutorials on the subject.

Understanding the URL Components:

In the realm of ad server configurations, we often encounter various conditions like placeholders, existence checks, and mappings. These conditions involve defining keys, target keys, and values, all of which play a crucial role in the URL transformation process.

The Client-Server Interaction:

Imagine a scenario where a client, whether it be a smart TV, laptop, or mobile phone, interacts with our system to request a vast (video ad serving template). The client, equipped with an app, initiates a GET request, sending a URL to our cloud service.

Deconstructing the URL:

Breaking down the URL, we identify three key elements: the base URL (statically configured), the endpoint (defining what content is requested, e.g., “vast”), and request parameters (highlighted in red). The real intrigue lies in these parameters.

URL Transformation Process:

Upon receiving the client’s URL, our cloud service parses it, checks for matching kill switches, and evaluates ad rules to determine the appropriate ad server for the request. The URL is then transformed to suit the ad server’s expectations.

Example Transformations:

  1. GDPR Parameter Transformation:

    • If the client sends gdpr=true, an existence check in the configuration can transform it to consent=1 for the ad server.
  2. Conditional Mapping - Country to Region:

    • Assuming the client provides a country=DE parameter, a conditional configuration can map it to region=Europe. This mapping is dynamic and based on your configurations.

Leveraging User and EPG Contexts:

URL transformations aren’t limited to request context parameters. RapidStream introduces user and EPG (Electronic Program Guide) contexts. These contexts allow for even more complex mappings and replacements.


  • If a user ID is provided, the ad server configuration can fetch additional user information, such as IAB categories, enhancing ad personalization.

  • Alternatively, an EPG ID can be utilized to fetch genre information, tailoring ads to specific genres.

Final Ad Serving Process:

In summary, the client’s request, adorned with URL transformations, is sent to the ad server. The ad server responds, and the final vast is sent back to the client, enabling seamless streaming with personalized advertisements.


Though the theoretical aspects might seem complex, understanding the URL transformation process is key to harnessing the full potential of ad server configurations in RapidStream. If you have questions or need clarification, don’t hesitate to reach out. Until our next tutorial, happy configuring! See you soon, and bye-bye.