WhatsApp released the Agent API but it needs a constant poller to run which sucks as all my apps are serverless that scale down to zero when there's no traffic. So I built Unpoll (unpoll.cc) that takes care of polling, cursor, webhooks and retries. You can simply add your agent's token which is stored encrypted and then send & receive messages by plain old HTTP requests and webhooks.

Lemme know what you guys think and happy to provide a free month to you as beta testers!