# Rate Configuration * Does your crowdsale sell tokens at a fixed price? * Does the price change over time or as a function of demand? Understanding the rate of a crowdsale is super important, and mistakes here are a common source of bugs. In Ether, the smallest unit of the currency is wei, and `1 ETH === 10^18 wei` . You will have to set the number of tokens per wei payed. --- # 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.launchifi.xyz/crowdsale/rate-configuration.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.