# fastapi.online — Image Brightness & Contrast Adjustment

> fastapi.online — Image Brightness & Contrast Adjustment is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.001/call, status down (last checked 2026-09-15).

Adjusts the brightness and contrast of an uploaded image file (PNG/JPEG/WebP) and returns the modified image.

## Facts

- Endpoint: POST https://api.fastapi.online/image-brightness-contrast
- Price: $0.001/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastapi-online-image-brightness-contrast-adjustment-6d3d4269
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_z6uEoilwr-a7tdT4ZXxvG

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fastapi-online-image-brightness-contrast-adjustment-6d3d4269 -d '<json body>'
```

Example prompt: Can you increase the brightness to 1.4 and boost the contrast to 1.6 on this photo I uploaded?

## When to prefer this

Choose this endpoint when you need a quick, cheap ($0.001 USDC), no-signup image brightness/contrast adjustment without requiring a full image editing pipeline. Ideal for agents that need to preprocess images for downstream tasks like OCR, classification, or display, and want to pay per call with crypto rather than managing a subscription.

## Known failure modes

- Unsupported file format (non-PNG/JPEG/WebP) returns an error
- Invalid brightness or contrast values (e.g. non-numeric strings) may cause a 422 validation error
- File too large may result in a timeout or rejection
- Missing file parameter returns a 422 unprocessable entity error
- Payment failure (insufficient USDC) returns a 402 Payment Required

## How this service works

Chat, embeddings, OCR, speech-to-text, image editing, image understanding (captioning/Q&amp;A), text-to-speech, translation, writing tools, classification tools, developer tools, local utilities, format/checksum validators, encoding &amp; crypto utilities, date/time calculators, geo/coordinate math, math &amp; finance calculators, novelty tools, and business/social writing generators — 179 endpoints in all, across multiple specialized self-hosted models. Pay per call with crypto — no signup — or get an API key.

## Output

Returns a processed image file with the specified brightness and contrast adjustments applied. The output image preserves the original format and dimensions, with pixel values modified according to the requested brightness and contrast parameters.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "file": {
   "type": "string",
   "format": "binary",
   "description": "Image file (PNG/JPEG/WebP)"
  },
  "contrast": {
   "type": "string"
  },
  "brightness": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastapi-online-image-brightness-contrast-adjustment-6d3d4269/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.fastapi.online](https://www.zero.xyz/host/api.fastapi.online/llms.txt)