> For the complete documentation index, see [llms.txt](https://docs.cartesi.io/llms.txt)

```python
from os import environ
import logging
import requests

logging.basicConfig(level="INFO")
logger = logging.getLogger(__name__)

rollup_server = environ["ROLLUP_HTTP_SERVER_URL"]
logger.info(f"HTTP rollup_server url is {rollup_server}")

class Counter:
    def __init__(self):
        self.value = 0

    def increment(self):
        self.value += 1
        return self.value

    def get(self):
        return self.value

counter = Counter()

def handle_advance(data):
    logger.info(f"Received advance request data {data}")
    new_val = counter.increment()
    logger.info(f"Counter increment requested, new count value: {new_val}")
    return "accept"


def handle_inspect(data):
    logger.info(f"Received inspect request data {data}")
    logger.info(f"Current counter value: {counter.get()}")
    return "accept"


handlers = {
    "advance_state": handle_advance,
    "inspect_state": handle_inspect,
}

finish = {"status": "accept"}

while True:
    logger.info("Sending finish")
    response = requests.post(rollup_server + "/finish", json=finish)
    logger.info(f"Received finish status {response.status_code}")
    if response.status_code == 202:
        logger.info("No pending rollup request, trying again")
    else:
        rollup_request = response.json()
        data = rollup_request["data"]
        handler = handlers[rollup_request["request_type"]]
        finish["status"] = handler(rollup_request["data"])

```