resources/uploads/methods/create/index.md 2026-07-07 08:02 UTC to 2026-07-09 20:58 UTC

Create upload

post /uploads

Create upload

Body Parameters

• bytes: number

  The number of bytes in the file you are uploading.

• filename: string

  The name of the file to upload.

• mime_type: string

  The MIME type of the file.

  This must fall within the supported MIME types for your file purpose. See the supported MIME types for assistants and vision.

• purpose: FilePurpose

  The intended purpose of the uploaded file.

  See the documentation on File purposes.

  • "assistants"

  • "batch"

  • "fine-tune"

  • "vision"

  • "user_data"

  • "evals"

• expires_after: optional object { anchor, seconds }

  The expiration policy for a file. By default, files with purpose=batch expire after 30 days and all other files are persisted until they are manually deleted.

  • anchor: "created_at"

    Anchor timestamp after which the expiration policy applies. Supported anchors: created_at.

    • "created_at"

  • seconds: number

    The number of seconds after the anchor time that the file will expire. Must be between 3600 (1 hour) and 2592000 (30 days).

Returns

• Upload object { id, bytes, created_at, 6 more }

  The Upload object can accept byte chunks in the form of Parts.

  • id: string

    The Upload unique identifier, which can be referenced in API endpoints.

  • bytes: number

    The intended number of bytes to be uploaded.

  • created_at: number

    The Unix timestamp (in seconds) for when the Upload was created.

  • expires_at: number

    The Unix timestamp (in seconds) for when the Upload will expire.

  • filename: string

    The name of the file to be uploaded.

  • object: "upload"

    The object type, which is always "upload".

    • "upload"

  • purpose: string

    The intended purpose of the file. Please refer here for acceptable values.

  • status: "pending" or "completed" or "cancelled" or "expired"

    The status of the Upload.

    • "pending"

    • "completed"

    • "cancelled"

    • "expired"

  • file: optional FileObject

    The File object represents a document that has been uploaded to OpenAI.

    • id: string

      The file identifier, which can be referenced in the API endpoints.

    • bytes: number

      The size of the file, in bytes.

    • created_at: number

      The Unix timestamp (in seconds) for when the file was created.

    • filename: string

      The name of the file.

    • object: "file"

      The object type, which is always file.

      • "file"

    • purpose: "assistants" or "assistants_output" or "batch" or 5 more

      The intended purpose of the file. Supported values are assistants, assistants_output, batch, batch_output, fine-tune, fine-tune-results, vision, and user_data.

      • "assistants"

      • "assistants_output"

      • "batch"

      • "batch_output"

      • "fine-tune"

      • "fine-tune-results"

      • "vision"

      • "user_data"

    • status: "uploaded" or "processed" or "error"

      Deprecated. The current status of the file, which can be either uploaded, processed, or error.

      • "uploaded"

      • "processed"

      • "error"

    • expires_at: optional number

      The Unix timestamp (in seconds) for when the file will expire.

    • status_details: optional string

      Deprecated. For details on why a fine-tuning training file failed validation, see the error field on fine_tuning.job.

Example

curl https://api.openai.com/v1/uploads \
    -H 'Content-Type: application/json' \
    -H "Authorization: Bearer $OPENAI_API_KEY" \
    -d '{
          "bytes": 0,
          "filename": "filename",
          "mime_type": "mime_type",
          "purpose": "assistants"
        }'

Response

{
  "id": "id",
  "bytes": 0,
  "created_at": 0,
  "expires_at": 0,
  "filename": "filename",
  "object": "upload",
  "purpose": "purpose",
  "status": "pending",
  "file": {
    "id": "id",
    "bytes": 0,
    "created_at": 0,
    "filename": "filename",
    "object": "file",
    "purpose": "assistants",
    "status": "uploaded",
    "expires_at": 0,
    "status_details": "status_details"
  }
}

Example

curl https://api.openai.com/v1/uploads \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -d '{
    "purpose": "fine-tune",
    "filename": "training_examples.jsonl",
    "bytes": 2147483648,
    "mime_type": "text/jsonl",
    "expires_after": {
      "anchor": "created_at",
      "seconds": 3600
    }
  }'

Response

{
  "id": "upload_abc123",
  "object": "upload",
  "bytes": 2147483648,
  "created_at": 1719184911,
  "filename": "training_examples.jsonl",
  "purpose": "fine-tune",
  "status": "pending",
  "expires_at": 1719127296
}