Canva image generation job API: AI credits and limits vs Sume

The short answer

Canva added preview image generation job APIs to Canva Connect on October 1, and every job you start spends the signed-in user's Canva AI credit allowance, with a limit of 20 requests per minute per user. A Sume image job is billed to the workspace that owns the API key instead, so it is the better fit when a backend, not a Canva user, is the caller.

Both are asynchronous: you start a job, keep its id, and read the result later. The differences are who pays, how long the result link lives, and whether the API is stable enough to build on.

Canva's create image generation job, side by side

Facts for Canva come from its changelog and its create image generation job reference. Sume facts come from the Sume docs.

What preview means for you

Canva states that preview APIs can change without notice, and that public apps using them cannot pass review. That limits this endpoint to private integrations today. If you ship to customers, assume you will rewrite the call when it leaves preview.

The 24-hour result URL matters more than it looks. Copy the image into your own storage in the same step that reads the result, because a link you saved in a spreadsheet will be dead by tomorrow.

The Sume equivalent

Submit the request, store the job id and poll /v1/jobs/:id/status. Reuse the same Idempotency-Key if your own process times out, so a retry returns the original job and does not bill a second image. See jobs and results.

curl -X POST https://api.sume.com/v1/image-1.0/generate \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Idempotency-Key: hero-2026-10-04-001" \
  -H "Content-Type: application/json" \
  -d '{"prompt":"Matte ceramic mug on oak, soft window light","aspect_ratio":"1:1","num_images":2}'

When to pick which

Pick Canva's endpoint when the image must land inside a Canva account under that user's own credits and you accept preview risk. Pick Sume when a server creates images for many users, you need up to four per call, and you want one job record you can poll, cancel and audit.