Edit a previously generated spritesheet: re-prompt its underlying animation (edit_mode "prompt"), extend the frame beyond its borders ("outpaint"), repair a bad loop ("fix_loop"), or re-render it with finer detail ("improve": the extra pass hydra-plus runs when it generates, on a spritesheet generated with hydra only - any other returns HTTP 400; a sheet generated on hydra-plus already has it). Pass the `spritesheet_url` you received from `animateSprite`, `animateSpriteKeyframes`, `transferMotion`, or an earlier edit - it must be a spritesheet you generated within the last 7 days; arbitrary external images are not accepted. Omit `duration`, `frames`, `frame_size`, `crop` and `model` to keep the source spritesheet's values. A `prompt` is required for edit_mode "prompt", optional for "outpaint", and not accepted for "fix_loop" or "improve"; optionally add up to 5 reference `images` (URL or base64) to guide the edit. The job result is the same result shape as animateSprite (spritesheet URL, frame layout, optional GIF or individual frames). Credits are held when the job is accepted; the final charge is rate × seconds of video generated, never more than was held, and the difference (or everything, if the job fails or is cancelled) is refunded. The returned sheet is then trimmed to its best loop and can run slightly shorter than the video; that trim is not deducted. Prompt edits are priced per model (credits/second × duration) and held for the duration you requested; "outpaint", "fix_loop" and "improve" run a lighter pipeline in which `model` is ignored and are billed at a flat 1 credit per second of output, held for and capped at the length of the source spritesheet's video (`duration` does not change their price). Outpaint decides the extra margin itself - there is no amount parameter. The result carries the same fields as animateSprite (`spritesheet_url`, `video_url`, grid fields); new audio is generated only by prompt edits on hydra: "fix_loop", "outpaint" and "improve" do not regenerate it, and their result carries the source spritesheet's `audio_url` when it had one. Pass an optional `request_id` to tag the result for later retrieval via listGenerations (type spritesheet). Async generation job: returns `{id, status}` - poll `getApiJob` (job and credit contract: see the server instructions).
Credits: edit_mode "fix_loop" / "outpaint": flat 1 credit per second of output, capped at the source spritesheet's video length, no minimum, model ignored; edit_mode "improve" (hydra spritesheets only): flat 1 credit per second of output, same terms; edit_mode "prompt": per model as listed - credits/s × seconds, per model: Hydra 3/s, Forge 2/s, Forge Pixel 2/s; see this endpoint's full pricing table in the API docs.
