MODEL IDsourceful:riverflow-2.5@fast
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Riverflow 2.5 Fast

Sourceful
by Sourceful

Riverflow 2.5 Fast is the speed-focused variant in Sourceful's Riverflow 2.5 family. It supports both text-to-image and image-to-image workflows through the 2.5 generation endpoints, making it suitable for rapid creative iteration, packaging exploration, branded product visuals, and latency-sensitive production pipelines that still need strong visual control.

Riverflow 2.5 Fast

API Options

Platform-level options for task execution and delivery.

taskType

stringrequiredvalue: imageInference

Identifier for the type of task being performed

taskUUID

stringrequiredUUID v4

UUID v4 identifier for tracking tasks and matching async responses. Must be unique per task.

outputType

stringdefault: URL

Image output type.

Allowed values3 values

outputFormat

stringrequired*default: JPG

Specifies the file format of the generated output. The available values depend on the task type and the specific model's capabilities.

  • `JPG`: Best for photorealistic images with smaller file sizes (no transparency).
  • `PNG`: Lossless compression, supports high quality and transparency (alpha channel).
  • `WEBP`: Modern format providing superior compression and transparency support.
**Transparency**: If you are using features like background removal or LayerDiffuse that require transparency, you must select a format that supports an alpha channel (e.g., `PNG`, `WEBP`, `TIFF`). `JPG` does not support transparency.
Allowed values3 values

outputQuality

integermin: 20max: 99default: 95

Compression quality of the output. Higher values preserve quality but increase file size.

webhookURL

stringURI

Specifies a webhook URL where JSON responses will be sent via HTTP POST when generation tasks complete. For batch requests with multiple results, each completed item triggers a separate webhook call as it becomes available.

Learn more1 resource

deliveryMethod

stringdefault: sync

Determines how the API delivers task results.

Allowed values2 values
Returns complete results directly in the API response.
Returns an immediate acknowledgment with the task UUID. Poll for results using getResponse.
Learn more1 resource

uploadEndpoint

stringURI

Specifies a URL where the generated content will be automatically uploaded using the HTTP PUT method. The raw binary data of the media file is sent directly as the request body. For secure uploads to cloud storage, use presigned URLs that include temporary authentication credentials.

Common use cases:

  • Cloud storage: Upload directly to S3 buckets, Google Cloud Storage, or Azure Blob Storage using presigned URLs.
  • CDN integration: Upload to content delivery networks for immediate distribution.
// S3 presigned URL for secure upload
https://your-bucket.s3.amazonaws.com/generated/content.mp4?X-Amz-Signature=abc123&X-Amz-Expires=3600

// Google Cloud Storage presigned URL
https://storage.googleapis.com/your-bucket/content.jpg?X-Goog-Signature=xyz789

// Custom storage endpoint
https://storage.example.com/uploads/generated-image.jpg

The content data will be sent as the request body to the specified URL when generation is complete.

safety

object

Content safety checking configuration for image generation.

Properties1 property
safety » checkContent

checkContent

booleandefault: false

Enable or disable content safety checking.

ttl

integermin: 60

Time-to-live (TTL) in seconds for generated content. Only applies when outputType is URL.

includeCost

booleandefault: false

Include task cost in the response.

numberResults

integermin: 1max: 20default: 1

Number of results to generate. Each result uses a different seed, producing variations of the same parameters.

Inputs

Input resources for the task (images, audio, etc). These must be nested inside the inputs object.

inputs » referenceImages

referenceImages

array of stringsmin items: 1max items: 4

List of reference images (UUID, URL, Data URI, or Base64).

inputs » fonts

fonts

array of objectsmax items: 2

Font references containing a font URL and the text to render.

Properties2 properties
inputs » fonts » text

text

stringrequiredmin: 1

Text to render with this font.

inputs » fonts » url

url

stringrequiredURI

Font file URL. Must be ttf, otf, woff, or woff2.

Core Parameters

Primary parameters that define the task output.

model

stringrequiredvalue: sourceful:riverflow-2.5@fast

Identifier of the model to use for generation.

Learn more3 resources

positivePrompt

stringrequiredmin: 2max: 24000

Text prompt describing elements to include in the generated output.

Learn more1 resource

width

integerrequired*paired with height

Width of the generated media in pixels.

Learn more2 resources

height

integerrequired*paired with width

Height of the generated media in pixels.

Learn more2 resources

resolution

stringdefault: 1K

Resolution preset for the output. When used with input media, automatically matches the aspect ratio from the input.

Allowed values2 values

Settings

Technical parameters to fine-tune the inference process. These must be nested inside the settings object.

settings » backgroundColor

Hex color composited when backgroundMode is solid.

settings » backgroundMode

backgroundMode

stringdefault: original

Background handling mode for the final output.

Allowed values3 values
Keep the original background.
Remove the background for a transparent result.
Replace the background with a solid color.
settings » enhancePrompt

enhancePrompt

booleandefault: false

Enhance the prompt with use-case context before generation.

settings » scoringPrompt

scoringPrompt

stringmin: 1

Free-text quality rubric used when scoring candidate outputs.

settings » scoringRubric

scoringRubric

array of objectsmin items: 1max items: 8

Controlled scoring dimensions that replace the default sub-score dimensions for the requested flow.

Properties6 properties
settings » scoringRubric » key

key

stringrequired

Unique machine-readable dimension key.

settings » scoringRubric » label

label

stringrequiredmin: 1max: 80

Short human-readable dimension label.

settings » scoringRubric » description

description

stringrequiredmin: 1max: 1000

Judging criteria for this score dimension.

settings » scoringRubric » weight

weight

floatrequired

Scoring weight. Normalized internally, so weights need not sum to 1.

settings » scoringRubric » passingScore

passingScore

floatmin: 0max: 1

Minimum score this dimension must reach.

settings » scoringRubric » scoreGuidance

scoreGuidance

array of objectsmax items: 5

Scoring anchors that define what the normalized scale means.

Properties2 properties
settings » scoringRubric » scoreGuidance » score
score
floatrequiredmin: 0max: 1

Normalized score anchor.

settings » scoringRubric » scoreGuidance » description
description
stringrequiredmin: 1max: 500

What this score anchor means for the judge.

settings » thinkingLevel

thinkingLevel

stringdefault: medium

Controls the depth of internal reasoning the model performs before generating a response.

Allowed values3 values