Create a tus upload

Creates a resumable upload resource from validated Assembly metadata.

For a normal fixed-size upload, first create an Assembly with num_expected_upload_files set to the number of files. Copy its assembly_ssl_url and tus_url into the example below. Do not substitute the general API hostname for the returned tus_url.

This example reserves four bytes, then uploads the text file. For a real file, use its byte length and send its bytes in the PATCH request.

assembly_ssl_url='<assembly_ssl_url from the creation response>'
tus_url='<tus_url from the creation response>'
assembly_metadata=$(printf %s "$assembly_ssl_url" | base64 | tr -d "\n")

curl --fail-with-body -sS --include --request POST \
  --url "$tus_url" \
  --header 'tus-resumable: 1.0.0' \
  --header 'upload-length: 4' \
  --header "upload-metadata: assembly_url $assembly_metadata,filename ZmlsZS50eHQ=,fieldname ZmlsZQ=="

A successful 201 response returns the upload URL in its location header. Copy that URL below. Keep it so an interrupted transfer can resume at the server’s reported offset.

upload_url='<Location response header>'
curl --fail-with-body -sS --request PATCH \
  --url "$upload_url" \
  --header 'tus-resumable: 1.0.0' \
  --header 'upload-offset: 0' \
  --header 'content-type: application/offset+octet-stream' \
  --data-binary 'file'

See the resumable upload guide for recovery and completion. Deferred lengths, concatenation, and exact header grammars are covered below.

For parallel uploads, create partial resources, upload their bytes, then create a final resource that concatenates them. Only the final file becomes an Assembly input and runs through your Template. Set num_expected_upload_files to the number of final files, not the number of partial resources. Include assembly_url, filename, and fieldname metadata on every partial and final creation request. With tus-js-client, also supply these fields in metadataForPartialUploads when using parallelUploads.

Leave Upload-Concat out for a normal upload. Set it to partial on each partial creation request. After all partial uploads finish, create the final resource with:

Upload-Concat: final;<PARTIAL_UPLOAD_URL_1> <PARTIAL_UPLOAD_URL_2>

Replace the placeholders with the complete Location URLs returned for the partial uploads. Keep the semicolon immediately after final; separate the URLs with spaces. Their order determines the byte order in the final file.

Send assembly_url in the Upload-Metadata header with the Base64-encoded assembly_ssl_url value from the same validated Assembly response.

Binary request body. application/offset+octet-stream The body is optional.