Binary Data and Files

The bytes type allows you to handle binary data in both requests and responses.

Sending bytes

If your API needs to send a stream of bytes (i.e. typical for assets like audio, images and other files) then you can use the bytes type in the Fern Definition to model this.

audio.yml

1 service:
2   base-path: /audio
3   endpoints:
4     upload:
5       display-name: Upload audio
6       method: POST
7       path: /upload
8       content-type: application/octet-stream
9       request:
10         type: bytes
11         docs: The bytes of the MP3 file that you would like to upload

Receiving bytes

When handling binary data in responses, use type: file instead of type: bytes. The bytes type is only supported in requests.

On the other hand, if your API is returning a stream of bytes, then you can leverage the bytes type as a response.

textToSpeech.yml

1 service:
2   base-path: /tts
3   endpoints:
4     upload:
5       display-name: Upload audio
6       method: POST
7       path: ""
8       request:
9         name: TTSRequest
10         body:
11           properties:
12             text:
13               type: string
14               docs: The text that you want converted to speech.
15       response:
16         type: file
17         docs: The bytes of the audio file.