File Purposes

Every uploaded file has a purpose — a label that tells ai& how the file may be used and which model capabilities are required to reference it.

Supported purposes

Purpose	MIME types	Single-shot limit	Use with
vision	image/png, image/jpeg, image/webp, image/gif	100 MB	Vision-capable models — see Vision
video	video/mp4, video/webm, video/quicktime	Use Uploads API (8 GB)	Video-capable models — see Video Understanding

Inference from MIME

The purpose field is optional on upload. If you omit it, ai& infers the purpose from the file’s MIME type. This lets the official anthropic SDK — which doesn’t carry a purpose field — work drop-in.

curl https://api.aiand.com/v1/files \
  -H "Authorization: Bearer sk-..." \
  -F "file=@cat.png"
# inferred purpose: "vision"

Capability gating at request time

When you reference a file_id in a chat message, the file’s purpose must match a capability the target model declares:

• purpose: "vision" → model must have the vision capability.
• purpose: "video" → model must have the video capability.

Mismatched requests return 400 invalid_request_error without ever calling the model.

Note

Additional purposes (e.g. audio, assistants, batch) may be added in future versions — the upload endpoint will return a 400 with a clear error if you pass an unsupported one.