Riverflow V2 Fast Preview is the fastest variant of Sourceful's Riverflow V2 preview lineup. This preview version exceeds the performance of Riverflow 1 Family and is Sourceful's first unified text-to-image and image-to-image model family.
Pricing is $0.03 per output image, regardless of size.
Sourceful imposes a 4.5MB request size limit, therefore it is highly recommended to pass image URLs instead of Base64 data.
Modalities
Price
$0.03/image
Context
8K
Weekly Tokens
7.96M
Released
Dec 8, 2025
Create an API key from your OpenRouter dashboard and set it as an environment variable:
Use sourceful/riverflow-v2-fast-preview with the OpenRouter API:
OpenRouter supports image generation models that only output images and not text. These models can create images from text prompts when you specify modalities: ["image"] in your request. The generated images are returned as base64-encoded data URLs in the assistant message. Learn more about image generation.
In the examples below, the OpenRouter-specific headers are optional. Setting them allows your app to appear on the OpenRouter leaderboards.
For information about using third-party SDKs and frameworks with OpenRouter, please see our frameworks documentation.
Add "stream": true to your request body to receive responses as server-sent events:
Sends a request for a model response for the given chat conversation. Supports both streaming and non-streaming modes.
https://openrouter.ai/api/v1/chat/completionsBearer $OPENROUTER_API_KEYapplication/jsonoptional — your site URL, for rankingsoptional — your site name, for rankingssourceful/riverflow-v2-fast-previewCreates a streaming or non-streaming response using the OpenAI Responses API format.
Docshttps://openrouter.ai/api/v1/responsesBearer $OPENROUTER_API_KEYapplication/jsonoptional — your site URL, for rankingsoptional — your site name, for rankingssourceful/riverflow-v2-fast-preview