# Variables Variables can be used either in calls params and in called function input params. There is no type check for variables, so it is the responsible of the FCT builder & activator to do type checking offline. In order to allow variables as part of a standard EIP712 message, rarely used values were chosen to represent variables. Variables can be created from multiple sources: * Injected by the activator when executing an FCT (External) * Returned data for previous calls (Returned Data) * Runtime information taken from the EVM (Generic) --- # 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.intentable.io/intent-structure/variables.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.