# 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: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.zk.link/architecture/da-layer.md?ask= ``` The question should be specific, self-contained, and written in natural language. 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.