# Variables and File Upload

Altair provides convenient support for setting GraphQL query variables. These allow you create dynamic queries based on provided input (opens new window).

# File Upload

Originally written about here (opens new window).

You can use binary files as variables to upload them via GraphQL to server (if it implemented the GraphQL multipart request specification (opens new window)).

Altair supports uploading both single files and an array of files (by switching the file upload from single to multiple file mode, or using the dot notation in single file mode e.g. for an array named fileList, you define the files as fileList.0, fileList.1, fileList.2 and so on).

You add your files in the variables pane, and the files are added to the request as variables when the request is sent to the server.