Multipart uploads

Use multipart upload when a file is too large for a single transfer or individual parts need to be retried.

1. Create the upload

export LINGOPAL_API_KEY="your-api-key"

curl -X POST "https://api.lingopal.ai/v2/storage/uploads" \
  -H "X-API-Key: $LINGOPAL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "file_ext": "mp4",
    "file_size": 2147483648
  }'

curl -X POST "https://example.com/v2/storage/uploads" \  -H "Content-Type: application/json" \  -d '{    "file_ext": "mp4"  }'

{  "source_url": "https://cdn.example.com/presigned_upload/user_123/source.mp4",  "file_path": "presigned_upload/user_123/source.mp4",  "upload_id": "2~example-upload-id",  "upload_urls": [    {      "part_number": 1,      "upload_url": "https://example-bucket.s3.amazonaws.com/presigned_upload/user_123/source.mp4?partNumber=1&X-Amz-Signature=..."    }  ],  "method": "PUT",  "headers": {    "Content-Type": "video/mp4"  }}

Use the API Reference entry for createStorageUpload for exact request payload and response fields.

Save file_path, upload_id, source_url, and every item in upload_urls.

2. Upload every part

PUT each byte range to its corresponding presigned URL. Record the returned ETag and part number. Failed parts can be retried independently while their presigned URLs remain valid.

3. Resume an interrupted upload

An interrupted transfer does not restart from zero. The multipart session stays open on S3, so you can list the parts already confirmed and fetch fresh presigned URLs for the remaining parts:

export LINGOPAL_API_KEY="your-api-key"

curl -X POST "https://api.lingopal.ai/v2/storage/uploads/parts" \
  -H "X-API-Key: $LINGOPAL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "file_path": "presigned_upload/user/source.mp4",
  "upload_id": "upload-id",
  "file_size": 2147483648
}'

The response contains parts (confirmed part numbers with ETags and sizes), upload_urls (fresh presigned URLs for every part), part_size_bytes, and source_url.

1. PUT only the parts missing from parts, using their entries in upload_urls.
2. Complete the upload with the combined ETags as described below.

An unknown or expired upload_id returns 404 and the session must be recreated with createStorageUpload. Uploads owned by another user return 403.

4. Complete the upload

Send the saved file_path, upload_id, and ETags in part order:

export LINGOPAL_API_KEY="your-api-key"

curl -X POST "https://api.lingopal.ai/v2/storage/uploads/complete" \
  -H "X-API-Key: $LINGOPAL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "file_path": "presigned_upload/user/source.mp4",
  "upload_id": "upload-id",
  "etags": [
    {"part_number": 1, "etag": "etag-1"},
    {"part_number": 2, "etag": "etag-2"}
  ]
}'

curl -X POST "https://example.com/v2/storage/uploads/complete" \  -H "Content-Type: application/json" \  -d '{    "file_path": "presigned_upload/user_123/source.mp4",    "upload_id": "2~example-upload-id",    "etags": [      {        "part_number": 1,        "etag": "\\"9b2cf535f27731c974343645a3985328\\""      },      {        "part_number": 2,        "etag": "\\"2a1fd1f7bc39b3868d2a8f6fb50f6a7d\\""      }    ]  }'

{  "file_path": "presigned_upload/user_123/source.mp4",  "source_url": "https://cdn.example.com/presigned_upload/user_123/source.mp4"}

Use the API Reference entry for completeStorageUpload for response and validation details.

5. Register the source

Register the source_url with POST /v2/jobs/register to receive a job_id. Storage completion alone does not start processing.