Model & Media Specs

Task API uses modality-specific public fields for media specs and converts them to the selected upstream protocol. Use GET /v1/tasks/models as the source of truth for models, prices, capabilities, and the constraints actually returned for the current API key.

Video and 3D fields define the common contract, but they can be submitted only after an executable adapter, channel, and plan are configured and the model appears in the model list.

Common Specs by Modality

Modality	Public spec fields	Model-list constraints
image	image_size, aspect_ratio, n	supported_image_sizes, supported_aspect_ratios, min_images, max_images, max_input_images
video	duration, resolution, aspect_ratio, generate_audio	max_input_assets
3d	output_format	max_input_assets

Video uses params.inputs for first frames, last frames, and reference media. The public 3D parser accepts reference images only, but no 3D adapter is currently registered. The model list does not currently advertise video duration, resolution, aspect-ratio, audio, or 3D output-format value sets. The public parser validates their types and basic shape; the selected adapter and upstream service determine whether a particular combination is supported.

Portable Image Parameters

Parameter	Common values	Description
image_size	0.5K, 1K, 2K, 3K, 4K	Image size tier used for routing and billing. Some models support only a subset.
aspect_ratio	1:1, 16:9, 9:16, 4:3, 3:4, 3:2, 2:3, 4:5, 5:4, 21:9	Desired image ratio. Some models support only a subset.

Use params.extra_body when you need an upstream-specific option. Do not send params.size directly to /v1/tasks.

GPT Image 2

GPT Image 2 routes using the OpenAI Images protocol convert image_size and aspect_ratio into size. Every derived size uses edges divisible by 16, keeps each edge at or below 3840, keeps the long-to-short edge ratio at or below 3:1, and contains between 655,360 and 8,294,400 pixels.

image_size	aspect_ratio	size
1K	1:1	1024x1024
1K	16:9	1536x864
1K	9:16	864x1536
1K	4:3	1360x1024
1K	3:4	1024x1360
1K	5:4	1280x1024
1K	4:5	1024x1280
1K	3:2	1536x1024
1K	2:3	1024x1536
1K	21:9	1536x656
1K	9:21	656x1536
2K	1:1	2048x2048
2K	16:9	2048x1152
2K	9:16	1152x2048
2K	4:3	2048x1536
2K	3:4	1536x2048
2K	5:4	2000x1600
2K	4:5	1600x2000
2K	3:2	1536x1024
2K	2:3	1024x1536
2K	21:9	2048x880
2K	9:21	880x2048
3K	1:1	2880x2880
3K	16:9	3072x1728
3K	9:16	1728x3072
3K	4:3	3072x2304
3K	3:4	2304x3072
3K	5:4	3040x2432
3K	4:5	2432x3040
3K	3:2	3072x2048
3K	2:3	2048x3072
3K	21:9	3072x1312
3K	9:21	1312x3072
4K	1:1	2880x2880
4K	16:9	3840x2160
4K	9:16	2160x3840
4K	4:3	3264x2448
4K	3:4	2448x3264
4K	5:4	3200x2560
4K	4:5	2560x3200
4K	3:2	3504x2336
4K	2:3	2336x3504
4K	21:9	3808x1632
4K	9:21	1632x3808

When setting an exact size through params.extra_body.size, use auto or a WIDTHxHEIGHT value that meets the constraints above. params.extra_body.quality accepts only low, medium, high, or auto. Invalid values return 400 TASK_INVALID_REQUEST before an upstream request is sent.

Gemini Native

Gemini Native routes use image_size and aspect_ratio directly for image generation settings. Supported tiers vary by model. Check parameter_constraints from the model list endpoint before submitting.

Model	image_size	aspect_ratio
gemini-3.1-flash-image	0.5K, 1K, 2K, 4K	1:1, 1:4, 1:8, 2:3, 3:2, 3:4, 4:1, 4:3, 4:5, 5:4, 8:1, 9:16, 16:9, 21:9
gemini-3-pro-image	1K, 2K, 4K	1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9
gemini-2.5-flash-image	1K	1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9
gemini-3.1-flash-lite-image	1K	1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9

Gemini Native does not support 9:21. Use a ratio only if it appears in the current model list response.

Seedream

Seedream supports text-to-image, image-to-image, and multiple reference images. 1K requests are handled as 2K.

image_size	aspect_ratio	Actual size
2K	1:1	2048x2048
2K	3:4	1728x2304
2K	4:3	2304x1728
2K	16:9	2848x1600
2K	9:16	1600x2848
2K	3:2	2496x1664
2K	2:3	1664x2496
2K	21:9	3136x1344
3K	1:1	3072x3072
3K	3:4	2592x3456
3K	4:3	3456x2592
3K	16:9	4096x2304
3K	9:16	2304x4096
3K	2:3	2496x3744
3K	3:2	3744x2496
3K	21:9	4704x2016
4K	1:1	4096x4096
4K	3:4	3520x4704
4K	4:3	4704x3520
4K	16:9	5504x3040
4K	9:16	3040x5504
4K	2:3	3328x4992
4K	3:2	4992x3328
4K	21:9	6240x2656

Exact Parameters

If the caller knows a specific upstream parameter supported by the target model, put it in params.extra_body:

{
  "model": "seedream-5.0-lite",
  "modality": "image",
  "params": {
    "model": "seedream-5.0-lite",
    "prompt": "Generate a wide product image",
    "image_size": "3K",
    "aspect_ratio": "16:9",
    "extra_body": {
      "size": "4096x2304"
    }
  }
}

If extra_body conflicts with portable sizing fields, the final upstream request uses extra_body. Billing is calculated from the final request and the actual result size tier.