curl -d to Sume /v1/videos gives 415: add the JSON Content-Type

A POST /v1/videos whose body is not application/json is answered with 415 unsupported_media_type, and details.received_content_type shows what the server saw. The usual cause is curl -d '{...}' with no -H "Content-Type: application/json": curl sends application/x-www-form-urlencoded by default for -d.

Reading the 415

The error uses the standard Sume envelope with a request id. It is a client error and a retry with the same headers will give the same answer, so fix the header rather than adding a backoff.

Validation happens before any cost estimate or reservation, so the 415 bills nothing.

The working command

The command below sends both headers and a body that matches the docs. It prints the id and polling_url from the 202 response. A bare object comes back, so jq reads the keys without .data.

curl -s -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{"model":"wan-3.0","prompt":"A paper boat on a rainy street","duration":5,"resolution":"720p","aspect_ratio":"9:16"}' \
  | jq '{id, polling_url, status}'

Why this is worth a header check

A 415 is cheap to fix, but it hides behind the same symptom as other client mistakes: the call fails, no job exists, and no polling_url comes back. Many wrappers swallow the body and show only the status, so an engineer sees 415 and has to guess. Print the envelope, which names the received content type and carries a request id, and the cause is on the screen.

Another detail: a failing POST has no job, so there is nothing to poll or cancel. Do not start a poll loop on a response that has no polling_url; check for the 202 first. In a script, test the HTTP status before you read the body, and stop on anything that is not 202.

Other clients

The same cause shows up elsewhere: an HTTP client that is given a string body may set a text content type, a form helper may send multipart, and a shell variable that holds the JSON may be passed through a wrapper that drops headers. If the 415 persists, print the headers your client sends and compare them with details.received_content_type.

Multipart is a related case on the image-edit route; see the multipart 415 post. For a script that checks the whole flow, see the curl and jq video step.

• Use --fail-with-body in scripts so a 415 prints the envelope.
• Generate a fresh Idempotency-Key for each new clip, not for each retry.
• Keep the key out of shell history by reading it from the environment.