AI Images. Pay per pixel.

Quick start

# Step 1: Get payment challenge
curl -X POST https://paid-image-api-production.up.railway.app/v1/images/generate \
  -H "Content-Type: application/json" \
  -d '{"prompt": "a sunset over mountains", "model": "gemini-3-pro-image-preview"}'

# Step 2: Pay via Tempo, then retry with credential
curl -X POST https://paid-image-api-production.up.railway.app/v1/images/generate \
  -H "Content-Type: application/json" \
  -H "Authorization: Payment <base64url-credential>" \
  -d '{"prompt": "a sunset over mountains", "model": "gemini-3-pro-image-preview"}'

// Get payment challenge
const res = await fetch("https://paid-image-api-production.up.railway.app/v1/images/generate", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    prompt: "a sunset over mountains",
    model: "gemini-3-pro-image-preview"
  })
});

// Parse 402 challenge from WWW-Authenticate header
const challenge = res.headers.get("WWW-Authenticate");

// ... sign Tempo tx, build credential, retry with Authorization header

import requests

# Get payment challenge
res = requests.post(
    "https://paid-image-api-production.up.railway.app/v1/images/generate",
    json={"prompt": "a sunset over mountains", "model": "gemini-3-pro-image-preview"}
)

# Parse 402 challenge
challenge = res.headers["WWW-Authenticate"]

# ... sign Tempo tx, build credential, retry with Authorization header