curl --request POST \
  --url https://api.runtools.ai/v1/agent-attachments/{id}/complete \
  --header 'Authorization: Bearer <token>'

{
  "data": {
    "attachment": {
      "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "threadId": "<string>",
      "filename": "<string>",
      "contentType": "<string>",
      "sizeBytes": 123,
      "status": "pending",
      "materializations": [
        {}
      ]
    }
  }
}