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Overview

Seedance 2.5 is a video generation model for prompt-only video, first-and-last-frame animation, and multimodal reference workflows. Use this page when you need up to 30-second video generation with optional image, video, or audio references, or when you want to review low-cost 480p Drafts before producing selected results in 1080p.
In omni_reference mode with video references, the generation system infers whether your task is reference generation (creating a new video guided by reference media) or video editing (modifying elements within an existing reference video):
  • Video editing (modifying original clips): If your prompt instructs changes to a reference video (such as replacing subjects, altering outfits, or modifying scene elements), set duration to -1 and aspect_ratio to auto so output attributes adapt to the source clip.
  • Reference generation (creating new clips): If you only want to borrow motion, lighting, or style to create a new scene, describe the features to reference rather than commanding edits to the source footage.
  • Recommended fallback: If your prompt could be interpreted as editing or you are unsure how the model will classify it, pass duration: -1 and aspect_ratio: "auto" to prevent parameter mismatch failures.

Endpoint and authentication

Base URL:
All requests require your APIXO API key:
Submit requests also require:
Save about 57% on a four-candidate workflow and roughly double iteration efficiency. Generate inexpensive 480p Drafts for review, then convert only the selected Draft into a 1080p Final. This avoids repeatedly paying for full-resolution candidates while preserving the Draft’s generation conditions, composition, motion, duration, and aspect ratio for the Final generation.

Step 1: Generate a 480p Draft

Set input.draft=true. resolution may be omitted because Draft generation is fixed to 480p.
Poll the returned task ID until the Draft reaches state=success. Keep this APIXO task ID; it is the value used as draft_task_id in the next step.

Step 2: Generate the 1080p Final

Send the successful Draft task ID. resolution may be omitted because Final generation is fixed to 1080p.
The Final inherits the Draft’s generation conditions. Do not resend prompt, reference media, mode, duration, aspect_ratio, or sound. A successful Draft can be reused to create multiple independent Finals for 7 days. Each Final returns its own task ID and is charged to the API key that submits that Final request.

Why this workflow saves about 57%

For a no-video-reference workflow that compares four candidates of the same duration:
The exact savings depend on candidate count, output duration, and whether video references are used. The largest efficiency gain comes from reviewing several Drafts and generating 1080p only for selected results.

Copy-paste async quickstart

This minimal request submits a text-to-video task and returns a taskId.
Successful response:
Save the taskId; you need it to poll for the final result.

Poll for result

Processing response:
Success response:
Failed response:
Parse resultJson after state becomes success:

Request body

Text-to-video

Dynamic duration

Use duration=-1 when you want the generation system to decide the final output length.

First-and-last-frames

Omni-reference

Parameters

string
default:"async"
Result delivery mode. Omit this field or use async for polling with statusTask, or use callback for webhook delivery.
string
Required when request_type is callback. Must be a public HTTPS URL that can receive the final task payload. See Webhooks.
object
required
Seedance 2.5 input parameters.

Draft and Final input rules

For Final requests, generation fields such as prompt, reference URLs, mode, duration, aspect_ratio, sound, and nsfw_checker are inherited from the Draft and must not be resent. draft=true and draft_task_id are mutually exclusive.
In omni_reference, audio-only requests are supported. The video-reference rate only applies when video_urls is provided.
Use public, directly accessible URLs for all reference media. Video and audio durations are checked before the task is submitted.
image_urls examples use URL strings. The API also accepts object items with a non-empty url field and normalizes them to URL strings.

Reference generation vs. video editing

When providing reference videos in omni_reference mode, Seedance 2.5 infers whether your goal is to generate an entirely new video inspired by the source or to edit the source clip directly.
Best practice when intent is ambiguous: If your prompt combines new scene descriptions with elements referenced from an existing video, or if you are unsure whether the generation system will classify the prompt as editing, set "duration": -1 and "aspect_ratio": "auto". This allows the engine to adapt dynamically to the reference footage rather than failing due to fixed duration or aspect ratio constraints.

Response format

Submit task response

POST /generateTask/seedance-2-5 returns a task ID when the task is accepted:
integer
API status code. 200 means the task was accepted.
string
Human-readable status message.
string
Unique task identifier used with the status endpoint.

Status response fields

string
Unique task identifier.
string
Current task state: pending, processing, success, or failed.
string
JSON string containing generated video URLs in resultUrls. Present when state is success.
string
Machine-readable failure code. Present when state is failed.
string
Human-readable failure message. Present when state is failed.
integer
Task creation timestamp in Unix milliseconds.
integer
Task completion timestamp in Unix milliseconds. Present after completion.
integer
Processing duration in milliseconds. Present after completion when timing data is available.
object
Final billing snapshot under data.billing, returned on successful terminal status and callback responses for new tasks. Older tasks may omit this object; see Billing for compatibility rules.
string
Settlement status. The final snapshot uses final.
string
Opaque identifier of the billing rule captured when this task was created. Do not infer the rule from polling time.
number
Actual total reference-video duration in seconds. Zero without video references; this is not raised to the minimum billable input.
number
For new tasks with video references, ceil(outputVideoSeconds * 2 / 3), rounded upward to a whole second. Zero without video references or under the original rule.
number
The larger of inputVideoSeconds and minimumInputVideoSeconds; zero without video references.
number
Output duration used for billing, in seconds. For duration=-1, this is the actual generated duration, rounded half up to 3 decimal places. For a Final, it is the source Draft’s actual output duration.
number
Total billed seconds: outputVideoSeconds + billableInputVideoSeconds.
string
Duration unit. The value is second.
string
Additional field for settled duration=-1 tasks: round half up to 3 decimal places. May be absent for fixed-duration and Final tasks.
integer
Number of reference videos included in inputVideoSeconds. Returned for settled duration=-1 tasks; may be absent for fixed-duration and Final tasks.
integer
Number of output videos included in outputVideoSeconds. Returned for settled duration=-1 tasks; may be absent for fixed-duration and Final tasks.

Webhook callback mode

Use callback mode when your backend should receive the final result automatically instead of polling.
The callback payload uses the same top-level shape as status polling with code, message, and data. Successful callbacks include the final state and resultJson. For new tasks, including fixed-duration, duration=-1, Draft, and Final tasks, successful terminal callbacks include the same data.billing object returned by status polling. See Webhooks for delivery requirements and retry behavior.

Billing

Seedance 2.5 is billed per second. The selected resolution and whether omni_reference includes video_urls determine the per-second unit price.
For iterative production, generate 480p Drafts first and create 1080p only from the selected Draft. In the four-candidate example above, this reduces generation spend by 57.5% and can roughly double iteration efficiency by avoiding repeated full-resolution generations.
Formula without video reference:
Formula with video reference:
text-to-video and first_and_last_frames always use the without-video-reference rate. omni_reference uses the with-video-reference rate only when video_urls is provided. Image and audio references do not add extra billable seconds. ceil rounds upward to the next whole second. The minimum applies once to the total reference-video duration, not separately to each video. For example, 5 output seconds with 3 actual reference seconds bills 5 + max(3, 4) = 9 seconds; 6 output seconds with 2 actual reference seconds bills 10 seconds. This rule applies to tasks created after the billing update. Existing tasks retain the rule captured at creation: with video references, (output duration + actual total reference video duration) * unit price; without video references, output duration only. Per-second prices, custom prices, and user discounts are unchanged. Polling or receiving a callback after the update does not change an existing task’s rule. For new duration=-1 tasks, APIXO pre-charges using an estimated 30-second output:
  • Without video references: 30 * unit price.
  • With video references: (30 + max(actual total reference video seconds, 20)) * unit price, because ceil(30 * 2 / 3) = 20.
After success, APIXO recalculates billable seconds using the actual output duration and the task’s captured rule, then refunds any excess using the effective unit price captured at creation, including applicable custom prices and discounts. The final charge is rounded to four decimal places before subtracting it from the original charge to calculate the refund. For example, with 3 reference-video seconds, pre-charge covers 50 seconds; if actual output is 5 seconds, final billing covers 9 seconds. Older automatic-duration tasks retain their original input-plus-output rule for both pre-charge and settlement. Draft creation is charged as a normal 480p generation using the same formulas and, for duration=-1, the same pre-charge and settlement rules. Each Final is a separate new task charged at the 1080p rate to the API key that submits it:
  • Without video references: use the source Draft’s actual output seconds.
  • With video references: Draft actual output seconds + max(Draft actual total reference video seconds, ceil(Draft actual output seconds * 2 / 3)).
  • For an automatic-duration Draft, use its final settled actual output duration, rounded half up to three decimal places. A Draft settled at 10.080 seconds with 3 actual reference-video seconds gives 10.080 + max(3, 7) = 17.080 billable seconds for a new Final.
  • Use the original actual reference duration, not the Draft’s minimum or billable input duration. Each reuse is billed independently. A Final created after the update uses the new rule even if its source Draft used the original rule; the Draft’s own charge is unchanged.
Successful terminal responses for new tasks include the final billing snapshot under data.billing; it is no longer limited to duration=-1. Fixed-duration, Draft, and Final tasks include the common fields. Automatic-duration tasks include additional rounding and video-count fields, as in this example:
Successful terminal status and callback responses for new tasks include data.billing. Duration values use seconds with three decimal places; minimumInputVideoSeconds is a whole-second ceiling. inputVideoSeconds remains the actual input duration, while billableInputVideoSeconds is the charged input duration. The snapshot remains stable on repeated polling. Older tasks may omit billing or the new fields; clients must not require them for historical tasks. totalBillableSeconds is outputVideoSeconds + billableInputVideoSeconds. Without video references, actual, minimum, and billable input seconds are all zero. Under the original rule, the minimum is zero and billable input equals actual input. Older automatic-duration tasks can still return a final snapshot under their original rule. For current route and market comparison pricing, see Pricing.

Latency and polling

Seedance 2.5 tasks are asynchronous. Actual latency may vary by prompt complexity, duration mode, resolution, reference media accessibility, route queue load, and storage transfer time.
For production workloads, use callback mode to avoid frequent polling while video tasks run.
Result URLs are temporary. Download and store important outputs promptly after task completion. Rate limits and concurrency can vary by account, API key, and route. If you receive 429, slow down requests and retry with backoff. For account-level details, see System APIs.

Errors and troubleshooting

HTTP errors

Validation notes

Task failure codes

failCode identifies the task failure. Common values include: See Error Codes for the full error reference.