Files

Get file upload URL

Generates a presigned URL for uploading a file. After uploading, use the returned file_id as an attachment ID in messages.

POST /v1/custom/:integration_id/sessions/:session_id/files/upload-url

Path parameters

Parameter	Type	Required	Description
integration_id	UUID	Yes	Your custom integration ID.
session_id	UUID	Yes	The session ID.

Request body

{
  "filename": "receipt.pdf",
  "content_type": "application/pdf"
}

Field	Type	Required	Description
filename	string	Yes	Original filename.
content_type	string	Yes	MIME type of the file (e.g., image/png, application/pdf).

Response — 200 OK

{
  "request_id": "550e8400-e29b-41d4-a716-446655440009",
  "upload_url": "https://storage.example.com/presigned-upload-url",
  "file_id": "file-abc123"
}

Field	Type	Description
request_id	string	Unique identifier for this request.
upload_url	string	Presigned URL to upload the file via HTTP PUT.
file_id	string	File identifier to use in message attachments.

---

Get file download URL

Generates a presigned URL for downloading a previously uploaded file.

POST /v1/custom/:integration_id/sessions/:session_id/files/download-url

Path parameters

Parameter	Type	Required	Description
integration_id	UUID	Yes	Your custom integration ID.
session_id	UUID	Yes	The session ID.

Request body

{
  "file_id": "file-abc123"
}

Field	Type	Required	Description
file_id	string	Yes	The file identifier from a previous upload or webhook attachment.

Response — 200 OK

{
  "request_id": "550e8400-e29b-41d4-a716-446655440010",
  "download_url": "https://storage.example.com/presigned-download-url",
  "file_id": "file-abc123"
}