# Adding A GraphQL Operation In GraphQL, there are three types of operations: queries, mutations and subscriptions. Queries are used to fetch data and are similar to GET requests in RESTful APIs. Mutations change data, akin to POST, PUT, or DELETE actions in REST, allowing clients to insert, update, or delete data. Subscriptions provide a way to maintain real-time data flow, enabling clients to receive updates as they happen, which is particularly useful for dynamic user interfaces where data needs to reflect changes as they occur. TODO ... document steps. --- # 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.bluetext.dev/building-your-system/cillers-core/quick-start-guide/adding-a-graphql-operation.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.