# Extensions The rules deployed on a system out of the box are not permanently fixed. New rule packages can be installed at any time by a system administrator. ## Extension packages Extension packages are stored in a zip file containing a manifest that explains the attributes of any new rules, their functions and chain points. It must also contain a file with error messages that the rules can produce. In addition to this, an extension package contains the actual Java code for each new rule, input adaptor and any code libraries they may depend upon. ## Installing new extension packages As discussed in the section “**Keeping the product current**”, you can install new packages at any time and have the system automatically deploy them to the relevant servers. Please refer to that section for an in-depth example on how to install a new package. --- # 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.tomorrowx.com/cap/product-reference/administration-functions/extensions.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.