Proxy DataFast with Flask

pip install flask requests

from flask import Flask, request, Response
import requests

app = Flask(__name__)


def get_client_ip():
    """
    Return the real client IP address.
    If X-Forwarded-For exists (e.g. behind proxy/CDN), use the first value.
    Otherwise, fall back to Flask's request.remote_addr.
    """
    xff = request.headers.get("X-Forwarded-For")
    if xff:
        # Can be a comma-separated list: "client, proxy1, proxy2"
        parts = [ip.strip() for ip in xff.split(",")]
        if parts:
            return parts[0]  # left-most is always the original client IP
    return request.remote_addr


@app.route("/js/script.js")
def proxy_script():
    response = requests.get("https://datafa.st/js/script.js")
    return Response(
        response.content,
        content_type="application/javascript",
        headers={"Cache-Control": "public, max-age=31536000"},
    )


@app.route("/api/events", methods=["POST"])
def proxy_events():
    # Copy all incoming headers except those that must match the target
    excluded = {"host", "content-length"}
    headers = {
        key: value
        for key, value in request.headers.items()
        if key.lower() not in excluded
    }

    # Add the real client IP if not already set
    client_ip = get_client_ip()
    headers.setdefault("X-Forwarded-For", client_ip)

    # Forward the request body and headers to DataFast
    response = requests.post(
        "https://datafa.st/api/events",
        data=request.get_data(),
        headers=headers,
        timeout=5,
    )

    # Return DataFast's response back to the browser
    return Response(
        response.content,
        status=response.status_code,
        content_type=response.headers.get("Content-Type", "application/json"),
    )

<script
  defer
  data-website-id="yourwebsiteid"
  data-domain="yourdomain.com"
  src="/js/script.js"
></script>