Python

pip install prometheus-client

prometheus-client>=0.20.0

import time
from prometheus_client import Counter, start_http_server

emails_sent = Counter(
    'emails_sent_total',
    'Total number of emails sent',
    ['status'],
)

if __name__ == '__main__':
    start_http_server(9090)
    while True:
        emails_sent.labels(status='success').inc()
        time.sleep(1)

{
    "metrics": {
        "endpoint": "/metrics",
        "interval": 15,
        "port": 9090
    }
}