> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://buildwithfern.com/learn/llms.txt. ## 0.42.0-rc0 **`(feat):`** The Fern Definition now supports `conten-type` on multipart request properties. For example, to specify an `application/octet-stream` and `application/json` contnet types, use the snippet below: ```ts service: endpoints: upload: request: body: properties: file: type: file content-type: application/octet-stream metadata: type: unknown content-type: application/json ```