Website Change Monitoring, Done For You — or Build It Yourself

# Create a managed watch — Rendex renders the page in real Chrome on a
# schedule, runs a before/after visual diff, and alerts you on change.
curl -X POST https://api.rendex.dev/v1/watches \
  -H "Authorization: Bearer rdx_your_key" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://example.com/pricing",
    "name": "Pricing page",
    "diffMode": "visual",
    "threshold": 0.02,
    "intervalMinutes": 180,
    "webhookUrl": "https://hooks.yourapp.com/rendex-watch",
    "renderParams": { "fullPage": true }
  }'
# Rendex captures the baseline now, re-checks every 3 hours, and POSTs your
# webhook (with a highlighted diff overlay) the moment the page changes.

// Create a watch from any backend — POST /v1/watches, no SDK required.
const res = await fetch("https://api.rendex.dev/v1/watches", {
  method: "POST",
  headers: {
    Authorization: "Bearer rdx_your_key",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    url: "https://example.com/status",
    name: "Status page",
    diffMode: "both",          // visual + text diff
    threshold: 0.01,
    intervalMinutes: 30,
    notifyEmail: "you@youraccount.com", // must be your own account email
    renderParams: { fullPage: true },
  }),
});

const { data: watch } = await res.json();
console.log(`Watching ${watch.url} — next check ${watch.nextRunAt}`);

# Prefer to own the pipeline? Build it yourself on the screenshot API:
# capture a timestamped snapshot on your own schedule and diff it.
from rendex import Rendex
from pathlib import Path
from datetime import datetime, timezone
import hashlib

rendex = Rendex("YOUR_API_KEY")

def snapshot(url: str) -> None:
    result = rendex.screenshot(url=url, full_page=True, format="png")
    stamp = datetime.now(timezone.utc).strftime("%Y%m%dT%H%M%SZ")
    Path(f"snapshots/{stamp}.png").write_bytes(result.image)

    digest = hashlib.sha256(result.image).hexdigest()
    last = Path("snapshots/last.sha256")
    if last.exists() and last.read_text() != digest:
        print(f"Visual change detected on {url} at {stamp}")
    last.write_text(digest)

snapshot("https://example.com")