Fast image upscaling via Stability AI, pay-per-call over MPP/Tempo.
What it does
This endpoint provides access to Stability AI's Upscale Fast model through the Locus MPP (Micropayment Protocol) gateway. It accepts a source image and returns an upscaled version with improved resolution. The endpoint uses a simple per-call charge model settled via Tempo L2 in pathUSD.
Upscale Fast is the lightest upscaling option in the Stability AI suite available through this gateway, priced at $0.023 per call (23,000 base units of a 6-decimal stablecoin). It requires only an image as input and optionally accepts an output_format parameter (jpeg, png, or webp). The endpoint is part of a broader Stability AI service catalog on Locus MPP that includes image generation (Ultra, Core, SD3), editing (erase, inpaint, outpaint, search-and-replace, search-and-recolor), background removal and replacement, style transfer, sketch-to-image, 3D model generation, and audio generation/editing.
The endpoint is a POST-only route. The probe returned 404 on HEAD/GET, which is expected since the OpenAPI spec defines only a POST method. The OpenAPI schema is well-documented with clear request body definitions. Payment intent is "charge" (one-shot per call) using the Tempo settlement method. Note that no response schema is documented beyond a generic "200: Successful response," so the exact output format (base64 image, URL, etc.) must be inferred from Stability AI's upstream API documentation.
Capabilities
Use cases
- —Upscaling low-resolution product images for e-commerce listings
- —Enhancing user-uploaded photos before display or printing
- —Improving resolution of AI-generated images for higher-quality output
- —Batch upscaling thumbnails or preview images to full resolution
- —Preparing images for large-format display or print
Fit
Best for
- —Quick, low-cost image upscaling without prompt engineering
- —Agents or pipelines that need resolution enhancement as a step
- —Developers who want pay-per-call pricing without API key management
Not for
- —Creative upscaling with AI-generated detail (use Upscale Creative or Upscale Conservative instead)
- —Non-image tasks such as text generation or audio processing
- —High-volume batch jobs where a direct Stability AI subscription may be cheaper
Quick start
curl -X POST https://stability-ai.mpp.paywithlocus.com/stability-ai/upscale-fast \
-H "Content-Type: application/json" \
-d '{"image": "<base64-encoded-image>", "output_format": "png"}'Example
Request
{
"image": "<base64-encoded-image-string>",
"output_format": "png"
}Endpoint
Quality
The OpenAPI spec is detailed with clear request schemas and pricing for this endpoint. However, the probe did not capture a live 402 challenge (POST was not attempted; HEAD/GET returned 404 as expected for a POST-only route), no response schema is documented, and crawled pages returned only generic 404 JSON. The endpoint is likely live but liveness is not confirmed by the probe.
Warnings
- —Probe did not attempt POST; HEAD/GET returned 404, which is expected for a POST-only endpoint but means liveness is unconfirmed
- —No response schema documented — output format (base64, URL, binary) is unknown from this spec alone
- —Currency address 0x20c000000000000000000000b9537d11c60e8b50 assumed to be a 6-decimal stablecoin (pathUSD); if decimals differ, the $0.023 price estimate would be wrong
Citations
- —Upscale Fast endpoint charges 23,000 base units via Tempo settlementhttps://stability-ai.mpp.paywithlocus.com
- —Endpoint accepts POST with image (required) and output_format (optional) parametershttps://stability-ai.mpp.paywithlocus.com
- —Stability AI API reference available at platform.stability.aihttps://platform.stability.ai/docs/api-reference
- —LLM-oriented docs available at beta.paywithlocus.comhttps://beta.paywithlocus.com/mpp/stability-ai.md