Stable Diffusion V3 API Reference

Request body

Submit an async generation request. The model field selects the model; other fields are model-specific input parameters.

stringmodelrequired

Model identifier. Set to stability-ai/stable-diffusion-v3-medium/image-to-image.

Default: stability-ai/stable-diffusion-v3-medium/image-to-image

stringpromptrequired

The prompt to generate an image from.

stringimagerequired

The image URL to generate an image from.

Optional<number>guidance_scale

The CFG (Classifier Free Guidance) scale is a measure of how close you want the model to stick to your prompt when looking for a related image to show you.

Range: 0 to 20

Default: 5

Optional<integer>num_inference_steps

The number of inference steps to perform.

Range: 1 to 50

Default: 28

Optional<number>strength

The strength of the image-to-image transformation.

Range: 0.01 to 1

Default: 0.9

Optional<boolean>prompt_expansion

If set to true, prompt will be upsampled with more details.

Default: false

Optional<string>aspect_ratio

The aspect ratio of the generated image.

Allowed values: 21:9, 16:9, 3:2, 4:3, 5:4, 1:1, 4:5, 3:4, 2:3, 9:16

Optional<integer>seed

The same seed and the same prompt given to the same version of Stable Diffusion will output the same image every time.

Response Schema

The submit endpoint returns an accepted generation task. Poll the result endpoint with the returned id for terminal outputs or errors.

Optional<string>error

Error message if the task failed. Empty on success.

stringidrequired

Unique identifier for the generation task.

Optional<string>model

Model ID used for the prediction.

Optional<array>outputs

Array of generated content. Empty when status is not completed.

stringstatusrequired

Status of the task: pending, running, completed, failed, or timeout.

Allowed values: pending, running, completed, failed, timeout

Model capabilities

array<string>capability_tagsrequired

Capabilities declared by the model registry.

Default: image-to-image

stringexecution_moderequired

Execution mode declared by the model registry.

Default: async

# 1. Submit a generation request curl -X POST https://api.sandbase.ai/v1/run \ -H "Authorization: Bearer $SANDBASE_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "stability-ai/stable-diffusion-v3-medium/image-to-image", "prompt": "cat wizard, gandalf, lord of the rings, detailed, fantasy, cute, adorable, Pixar, Disney, 8k", "image": "https://static.sandbase.ai/examples/stability/stable-diffusion-v3-medium/image-to-image/input_image_0.png", "aspect_ratio": "21:9" }' # 2. If the response is still running, poll the returned id curl https://api.sandbase.ai/v1/run/run_abc123 \ -H "Authorization: Bearer $SANDBASE_API_KEY"