R httr2: submit an AI video job, poll it, and save the MP4 (Wan 3.0)

In R, httr2 is enough to generate a clip: build a request with request(), add the bearer token with req_auth_bearer_token(), send JSON with req_body_json(), and read the result with resp_body_json(). Sume answers the submit with 202 and a job id, and you read GET /v1/jobs/{id}/status until terminal is true (Sume jobs guide, read 2026-10-06). The finished file comes from GET /v1/videos/{id}/content?index=0, which needs the same key.

The script requests wan-3.0, 5 seconds, 720p. At $0.125 per second that is $0.625, reserved at submit.

What is the whole script?

Set SUME_API_KEY in the environment, for example in .Renviron. The loop stops after 120 reads.

library(httr2)

key  <- Sys.getenv("SUME_API_KEY")
base <- "https://api.sume.com"
stopifnot(nzchar(key))

submit <- request(paste0(base, "/v1/videos")) |>
  req_auth_bearer_token(key) |>
  req_headers(`Idempotency-Key` = "r-demo-wan-001") |>
  req_body_json(list(model = "wan-3.0", prompt = "A paper boat on a rain puddle",
                     duration = 5, resolution = "720p")) |>
  req_perform() |> resp_body_json()
id <- submit$id

for (i in 1:120) {
  Sys.sleep(15)
  s <- request(paste0(base, "/v1/jobs/", id, "/status")) |>
    req_auth_bearer_token(key) |> req_perform() |> resp_body_json()
  if (isTRUE(s$terminal)) break
  if (!is.null(s$next_poll_after_seconds)) Sys.sleep(max(0, s$next_poll_after_seconds - 15))
}
stopifnot(s$sume_status == "completed")

request(paste0(base, "/v1/videos/", id, "/content?index=0")) |>
  req_auth_bearer_token(key) |> req_perform(path = "clip.mp4")

What do the other resolutions cost?

Does re-running the poller bill a second clip?

No, as long as it only reads. Keep the paid POST /v1/videos in a separate step with an Idempotency-Key you own. A client-side give-up never cancels the render, so store the job id and read it again later instead of submitting a second time (Sume jobs guide, read 2026-10-06).