> For the complete documentation index, see [llms.txt](https://docs.zk.link/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zk.link/architecture/da-layer.md). # DA Layer > Data Availability (DA) entails making the transaction data available. DA layer is a critical component for rollups to ensure the capability to reconstruct the the rollup states when the rollup service halts unexpectedly. Both zkLink Nexus and zkLink Origin by default support the **primary chain** as the DA layer. Secondly, both Nexus and Origin support **Validium**, which involves an **external DA** solution. zkLink will integrate various third party modular DA solutions, such as Celestia, EigenDA, Avail, etc., to meet diverse demands from developers. Furthermore, zkLink DAO will have the option to organize a **Data Availability Committee** (DAC). This DAC serves as another option for developers, providing an additional choice for data availability assurance. --- # 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://docs.zk.link/architecture/da-layer.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.