app.py

from flask import Flask, request, jsonify
import requests

app = Flask(__name__)

@app.route('/', defaults={'path': ''})
@app.route('/<path:path>', methods=['GET', 'POST'])
def proxy(path):
    url = 'http://адрес_целевого_сервера/' + path
    headers = {'Content-Type': 'application/json'}
    response = requests.request(
        method=request.method,
        url=url,
        headers=headers,
        data=request.get_data(),
        cookies=request.cookies,
        stream=True,
    )
    return response.content, response.status_code, response.headers.items()

if __name__ == '__main__':
    app.run()