# Clay Clay is Arvo's filesystem. Clay is version-controlled, referentially-transparent, and global. While this filesystem is stored in the Clay module, it can be mirrored to Unix for convenience. Unix tells Clay whenever a file changes in the Unix copy of the filesystem so that the change may be applied. Clay tells Unix whenever an app or vane changes the filesystem so that the change can be effected in Unix. Clay includes three components: * Filesystem and version control algorithms, which are mostly defined in `+ze` and `+zu` in Zuse. * Write, query, and subscription logic. * Logic for communicating requests to, and receiving requests from, foreign ships. --- # 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.urbit.org/urbit-os/kernel/clay.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.