Source: https://ailoot.ai/models/en/doubao-seedance-2-0-fast-260128/ Canonical: https://ailoot.ai/models/en/doubao-seedance-2-0-fast-260128/ Language: en # ByteDance: Seedance 2.0 Fast [Markdown](https://ailoot.ai/models/en/doubao-seedance-2-0-fast-260128/index.md) · [JSON](https://ailoot.ai/models/en/doubao-seedance-2-0-fast-260128/facts.json) ## [ByteDance: Seedance 2.0 Fast](https://ailoot.ai/models/en/doubao-seedance-2-0-fast-260128/) Seedance 2.0 Fast is the Fast multimodal profile for video generation, editing and extension. It accepts text, image, video and audio references, supports synchronized or silent output, and documents 4–15-second clips at 480p or 720p. - [**Ailoot Ultra · Video** `POST /v1/videos` `doubao-seedance-2-0-fast-260128`](https://ailoot.ai/models/en/doubao-seedance-2-0-fast-260128/#method-0) About the model This description covers the model’s capabilities. Available in Ailoot inputs, outputs and options are listed for the selected method below. Seedance 2.0 Fast is the separately named Fast profile, selected with doubao-seedance-2-0-fast-260128. It supports video generation, editing and extension using text, images, video and audio references. The profile is useful when a scene brief needs more than a description of appearance: existing media can also communicate performance, camera language and sound. The Fast name distinguishes the request identity; it is not a promise that an individual asynchronous task finishes within a fixed time. Start with the element that should define the new shot. Text alone can describe a new scene. An image can establish a character, product or composition; a video can provide motion or an existing sequence to revise or continue. The documented content combinations include images with audio, video with audio and images, video and audio together, with text optional alongside visual media. These combinations do not describe a standalone audio-only request, so pair sound references with the visual source they should guide. Keep reference roles explicit in the content array and in the brief. image\_url, video\_url and audio\_url items can carry reference\_image, reference\_video and reference\_audio roles. Describe which image supplies the subject, which video supplies the camera or action and which audio supplies the soundtrack. For a product shot, an image might define the packaging while a video illustrates a movement past the object. Specify the desired ending so the short sequence has a useful closing view rather than stopping in the middle of an action. For editing, identify the source footage, the change and the continuity to retain. A background or lighting change should leave the intended subject and action clearly specified. For extension, explain what happens next and how the new movement connects to the existing scene. References guide the generation; inspect the actual join and complete clip for appearance, motion direction and timing rather than assuming the continuation preserves every frame-level detail. The documented 2.0 Fast range is four to fifteen whole seconds, with -1 available for a model-selected duration within that range. The default duration is five seconds. Output resolution is 480p or 720p, with 720p as the default and 1080p excluded. Choose among fixed 16:9, 4:3, 1:1, 3:4, 9:16 and 21:9 shapes, or adaptive framing. Adaptive framing follows the relevant prompt or reference context; a first-frame shot follows its opening image, while multimodal framing can prioritize video over images. Read the returned task fields for the actual duration and ratio. Use generate\_audio to choose whether the generated video includes synchronized sound. The documented default is true; false requests silence. With audio enabled, the profile generates voices, effects or background music from the prompt and visual content, and the guide recommends enclosing dialogue in double quotation marks. State the speaker and intended relationship between sound and action. Review speech with a fluent listener and check sound alignment across the clip, including any edited or extended segment. The 2.0 Fast guide excludes the older frames and camera\_fixed controls and does not support flex offline processing. Describe camera behavior in the scene and use duration for the clip length. Seed and watermark options remain documented. The same seed is not a guarantee of an identical output, so retain the completed artifact when comparing revisions instead of relying only on the request settings. Video-token usage is calculated as (input-video duration + output-video duration) × output width × output height × output frame rate / 1024. Requests containing input video and those without input video have distinct billing categories. The task query reports usage.completion\_tokens and usage.total\_tokens; retain these reported quantities with the completed clip. Submission returns a task identifier before the completed video is available. Follow processing status, then retrieve content.video\_url after success and keep the reported duration, resolution, ratio, frame rate and usage with the result. The expiry interval is measured from task creation, defaults to 172800 seconds and ranges from 3600 to 259200 seconds. Save the final clip with its references and prompt, then check subject identity, object contact, camera continuity and sound timing through the full sequence. **Ailoot Ultra · Video** `POST /v1/videos` `doubao-seedance-2-0-fast-260128` [`doubao-seedance-2-0-fast-260128`](https://ailoot.ai/models/en/#m=doubao-seedance-2-0-fast-260128&route=Ultra&caller=doubao-seedance-2-0-fast-260128&fmt=videos) ByteDance /`doubao-seedance-2-0-fast-260128` ### Overview Seedance 2.0 Fast is the Fast multimodal profile for video generation, editing and extension. It accepts text, image, video and audio references, supports synchronized or silent output, and documents 4–15-second clips at 480p or 720p. Accepted inputs Text · Images · Video · Audio Results Video ### Available in Ailoot · inputs & methods **Ailoot Ultra · Video** `POST /v1/videos` Input types `text`, `image`, `video`, `audio` Output types `video` | Field | Type | Requirement | Values & limits | Default | | --- | --- | --- | --- | --- | | Field`model` | Type`string` | RequirementRequired | Values & limits doubao-seedance-2-0-fast-260128 | Default— | | Field`content` | Type`array` | RequirementRequired | Values & limits Conditions: Native text/media objects; outer array must be non-empty. Nested node types are not validated by this Ailoot generic constructor. | Default— | | Field`generate_audio` | Type`boolean` | RequirementOptional | Values & limits Conditions: Synchronized sound embedded in video. | Defaulttrue | | Field`duration` | Type`integer` | RequirementOptional | Values & limits Conditions: Integer 4–15 or -1; actual output duration returned. | Default5 | | Field`resolution` | Type`string` | RequirementOptional | Values & limits 480p, 720p Conditions: 1080p explicitly unsupported for 2.0/fast. | Default720p | | Field`ratio` | Type`string` | RequirementOptional | Values & limits 16:9, 4:3, 1:1, 3:4, 9:16, 21:9, adaptive Conditions: Adaptive explicitly scoped to 2.0/fast/1.5; 2.5 example 16:9 only. | Defaultadaptive | | Field`watermark` | Type`boolean` | RequirementOptional | Values & limits | Defaultfalse | | Field`seed` | Type`integer` | RequirementOptional | Values & limits Minimum: -1 Maximum: 4,294,967,295 | Default-1 | | Field`execution_expires_after` | Type`integer` | RequirementOptional | Values & limits Minimum: 3,600 Maximum: 259,200 Unit: seconds | Default172,800 | | Field`service_tier` | Type`string` | RequirementOptional | Values & limits default Conditions: 2.0/fast exclude offline flex; 2.5 scope is not established. | Defaultdefault | | Field`safety_identifier` | Type`string` | RequirementOptional | Values & limits | Default— | | Field`tools` | Type`object` | RequirementOptional | Values & limits Conditions: Only 2.0/fast; documented type=web\_search. | Default— | Input material combinations Method parameters and lifecycle | Parameter | Contract | | --- | --- | | Parameter`content_type` | Contractapplication/json | | Parameter`required` | Contractcontent, model | | Parameter`optional` | Contractgenerate\_audio, duration, resolution, ratio, watermark, seed, execution\_expires\_after, service\_tier, safety\_identifier, tools | | Parameter`material_types` | Contracttext, image, video, audio | | Parameter`additional_properties` | Contracttrue | | Parameter`validation_scope` | ContractAiloot checks the required field types and a non-empty model/content array. Other request fields are preserved for the selected model. | | Parameter`material_combinations` | Contracttext, image, video, image, audio, image, video, video, audio, image, video, audio | | Parameter`optional_text_with_media` | Contracttrue | | Parameter`reference_media_count_and_size_limits` | Contractnull | Method aliases: `/v1/videos/generations` Lifecycle: `submit_once_poll_original` `GET /v1/videos/{request_id}` `GET /v1/videos/generations/{request_id}` `GET /v1/videos/{request_id}/content` `GET /v1/videos/generations/{request_id}/content` Create once and retain returned public id/polling\_url. Poll the original job; download actual owned content.video\_url after succeeded. ### Pricing ##### How the final charge is calculated The displayed rates estimate the cost before generation. The final charge is calculated from the cost recorded for the original generation. Measured output duration and forecast quantities are not the final billable quantity. Tariff references do not add request options. Supported parameters are listed for the selected method. Fast mode Not specified When fast mode is selected Flex mode Not specified When flex mode is selected Maximum reasoning effort Not specified When maximum reasoning effort uses the default adjustment #### Estimated rates for comparison #### Prices by configuration Match each charge to the conditions shown. Use one rate for each set of alternative configurations. | Configuration | Rate schedule | Forecast quantity | Billing unit | Charge | | --- | --- | --- | --- | --- | | ConfigurationBase token rates | Rate scheduleBase rate | Forecast quantity— | Billing unit— | Charge Input · Input tokens · Estimate for comparison only **—** / 1K tokens Output · Output tokens · Estimate for comparison only **—** / 1K tokens Input · Cache read · Estimate for comparison only **—** / 1K tokens Input · Cache write · Estimate for comparison only **—** / 1K tokens Input · Cache write, 1 hour · Estimate for comparison only **—** / 1K tokens | | ConfigurationInput contains video. | Rate schedule— | Forecast quantity— | Billing unitper 1,000 video tokens | Charge Output · Estimate for comparison only **$0.007536** per 1,000 video tokens | | ConfigurationInput contains no video. | Rate schedule— | Forecast quantity— | Billing unitper 1,000 video tokens | Charge Output · Estimate for comparison only **$0.013032** per 1,000 video tokens | | ConfigurationEstimated generation cost | Rate schedule— | Forecast quantityone generation estimate | Billing unit— | Charge Output · Estimated generation cost · Estimate for comparison only **$0.822402** estimate before generation This estimate is not an additional charge or a fixed rate for the completed generation. | Ailoot reserves an estimated amount before a request. After the result, it settles the final charge from measured usage. Streaming settlement uses the final usage record. [How reservation and settlement work →](https://ailoot.ai/docs/en/billing/reserve/) ### Example requests #### Ailoot Ultra · Video curl · create videocurl · read original taskcurl · download owned video ```bash set -eu : "${AILOOT_API_KEY:?Set your Ailoot API key}" cat > request.json <<'JSON_REQUEST' {"model":"doubao-seedance-2-0-fast-260128","content":[{"type":"text","text":"女孩抱着狐狸，女孩睁开眼，温柔地看向镜头，狐狸友善地抱着，镜头缓缓拉出，女孩的头发被风吹动"}]} JSON_REQUEST curl --fail-with-body --silent --show-error https://api.ailoot.ai/v1/videos \ -H "Authorization: Bearer $AILOOT_API_KEY" -H 'Content-Type: application/json' \ --data-binary @request.json -D response-headers.txt -o result.json ``` ```bash set -eu : "${AILOOT_API_KEY:?Set your Ailoot API key}" python3 - <<'PY_POLL' import json from pathlib import Path from urllib.parse import quote,urljoin,urlsplit r=json.loads(Path("result.json").read_text()) i=r.get("id") if not isinstance(i,str) or not i.startswith("native302_"):raise SystemExit("Keep original response/headers/id; do not resubmit creation.") u=urljoin("https://api.ailoot.ai",r.get("polling_url") or "/v1/videos/"+quote(i,safe="")) p=urlsplit(u) if p.scheme!="https" or p.netloc!="api.ailoot.ai" or not p.path.startswith("/v1/videos/"):raise SystemExit("Use actual Ailoot lookup path.") Path("poll-url.txt").write_text(u) PY_POLL curl --fail-with-body --silent --show-error "$(cat poll-url.txt)" -H "Authorization: Bearer $AILOOT_API_KEY" -D status-headers.txt -o status.json ``` ```bash set -eu python3 - <<'PY_ASSETS' import json from pathlib import Path from urllib.parse import urlsplit r=json.loads(Path("status.json").read_text()) if r.get("status")!="succeeded":raise SystemExit("Poll same original job until an owned result is returned.") u=r.get("content",{}).get("video_url") urls=[u] if isinstance(u,str) else u if not isinstance(urls,list) or not urls:raise SystemExit("No completed video URL.") for u in urls: if not isinstance(u,str):raise SystemExit("Invalid returned URL.") p=urlsplit(u) if p.scheme!="https" or p.netloc!="api.ailoot.ai" or not p.path.startswith("/v1/media/assets/") or not p.path.endswith("/content") or not p.query:raise SystemExit("Wait for actual Ailoot-owned signed result.") Path("asset-urls.txt").write_text("\n".join(urls)+"\n") PY_ASSETS index=0 while IFS= read -r asset_url; do curl --fail-with-body --silent --show-error "$asset_url" -o "video-${index}.bin" index=$((index + 1)) done < asset-urls.txt ``` ### Receive and save results #### Ailoot Ultra · Video Native JSON with public id/polling\_url. After publication content.video\_url contains Ailoot-owned signed URL(s); before publication selected output URLs are blanked. - `GET /v1/videos/{request_id}` - `GET /v1/videos/generations/{request_id}` - `GET /v1/videos/{request_id}/content` - `GET /v1/videos/generations/{request_id}/content` ##### Keep all completed results Save every completed video or returned file; retrieve every actual returned asset URL. Retain every actual URL in content.video\_url; index must identify a real returned output. ##### If the original response needs checking Preserve original response/headers/id and poll that operation; never resubmit unknown creation. Response fields | Field | Type | | --- | --- | | Field`id` | Typestring | | Field`provider_task_id` | Typestring | | Field`polling_url` | Typestring | | Field`status` | Typestring when supplied | | Field`content.video_url` | Typestring\|string\[\] | | Field`usage` | Typeobject when supplied | Errors and next steps | Response | Condition | Next step | | --- | --- | --- | | Response400 · `invalid_request_error` | ConditionInvalid JSON/model/required field types or content index. | Next step | | Response401 · `authentication_error` | ConditionInvalid Ailoot API key. | Next step | | Response404 · `not_found_error` | ConditionTask/output absent or not owned by same user/API key/group. | Next step | | Response502 · `result_pending_check` | ConditionOriginal submit/status incomplete; preserve original ID, no resubmit. | Next step | | Response503 · `result_pending_check` | ConditionOriginal media/route/settlement is being checked; continue original operation. | Next step | ### Aliases #### Model aliases **Ailoot Ultra** [`doubao-seedance-2-0-fast-260128`](https://ailoot.ai/models/en/#m=doubao-seedance-2-0-fast-260128&route=Ultra&caller=doubao-seedance-2-0-fast-260128&fmt=videos) #### Method path aliases `/v1/videos/generations` #### Related caller IDs [`doubao-seedance-2-0-fast-260128`](https://ailoot.ai/models/en/#m=doubao-seedance-2-0-fast-260128&route=Ultra&caller=doubao-seedance-2-0-fast-260128&fmt=videos) FAQ · ByteDance: Seedance 2.0 Fast What inputs and results are available? `POST /v1/videos` · `doubao-seedance-2-0-fast-260128`: `text`, `image`, `video`, `audio` → `video` Which fields does the request use? `POST /v1/videos` · `doubao-seedance-2-0-fast-260128`: `model`, `content`, `generate_audio`, `duration`, `resolution`, `ratio`, `watermark`, `seed`, `execution_expires_after`, `service_tier`, `safety_identifier`, `tools` What limits apply? `POST /v1/videos` · `doubao-seedance-2-0-fast-260128`: `seed.minimum`: `-1`; `seed.maximum`: `4294967295`; `execution_expires_after.minimum`: `3600`; `execution_expires_after.maximum`: `259200` Connect Ailoot to Claude Code, OpenCode, Hermes or your own app. ## The company and its project portfolio The company and its project portfolio: millions of customers; monthly sales in the billions. ## Buy tokens at a discount. 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