> For the complete documentation index, see [llms.txt](https://docs.cros.world/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cros.world/sdk-and-apis.md).

# SDK & APIs

Cros Ad platform is designed and built with `composability` as the key design principle.

* A **Software Development Kit (SDK)** for the creator and developer community to build innovative advertising and brand engagement experiences is one way to build and extend the platform capabilties for different game platforms by providing the right set of tools & libraries in the hands of the people.
* A modular & composable set of open APIs for demand partners, publisher platforms or mixed reality platforms for them to connect to the platform, publish an ad-campaign, submit a bid or fetch and serve an ad on the device - in other words programmatically extend the ad platform to their applications or products.

<figure><img src="/files/OrZsL7aCG8i2bPSmaixD" alt=""><figcaption><p>Composable APIs</p></figcaption></figure>

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