> For the complete documentation index, see [llms.txt](https://clients.medianova.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://clients.medianova.com/products/performance-cdn/dynamic-content-acceleration/advanced-configuration/headers/cors-header.md). # CORS Header Learn how CORS Header controls cross-origin access behavior for dynamic HTML responses. The **CORS Header** feature for Dynamic Content Acceleration operates the same way as in Static Content Delivery.\ It allows CDN edge servers to set or override the `access-control-allow-origin` header for HTML responses when you want to explicitly control which origins may access your resources. By default, the CDN forwards CORS headers returned by your origin; enabling this feature instructs the CDN to generate or override the header instead, using either a wildcard or a defined allow list. For configuration details, allowed domain behavior, and examples, refer to the main documentation:\ **Learn more in the** [**CORS Header documentation**](/products/performance-cdn/static-content-delivery/advanced-configuration/headers/cors-header.md)**.** --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://clients.medianova.com/products/performance-cdn/dynamic-content-acceleration/advanced-configuration/headers/cors-header.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.