I Ran 89,479 WhatsApp Messages Through WAHA. Twilio: $604.

Last month my WhatsApp stack moved 89,479 messages. I got no invoice for any of them. That is not a brag, it is the setup for an honest accounting. Because "self-hosting is cheaper" is the least interesting sentence in infrastructure, and it is usually said by someone who has never been paged at 7am by a bot that went quiet at 2am. I want to put a real number on both sides of that trade: the money Twilio would have charged, and the money self-hosting quietly takes back. All the numbers below were pulled or fetched on August 27, 2026 . The rate cards move quarterly, so check yours. The traffic, measured rather than estimated Five WhatsApp inboxes, bridged from WAHA into a self-hosted Chatwoot. Thirty days: messages Total 89,479 Inbound (from users) 45,563 Outbound (from us) 43,916 Most benchmarks stop here, multiply by a per-message rate, and publish. That answer is wrong, because Meta does not charge per message. It charges per template sent outside an open customer service window. Multiplying my full 89,479 by a template rate overstates the Meta line by about 3x. Multiplying just the outbound half still overstates it by about 1.5x. Since November 1, 2024 non-template messages are free. Since July 1, 2025 utility templates answering a user inside an open 24-hour window are also free. So the only line that costs money is the outbound message that goes out when nobody has written to you in the last day. Which means the number you actually need is not "how many messages," it is "how many outbound messages had no inbound message from that contact in the preceding 24 hours." The query that produces the real bill Here it is against Chatwoot's schema. It uses a window function rather than a correlated NOT EXISTS , because on a messages table of any size the correlated version will happily eat your connection pool. WITH src AS ( SELECT m . conversation_id , m . created_at , m . message_type FROM messages m WHERE m . inbox_id IN ( 27 , 23 , 46 , 50 , 48 ) -- your WhatsApp in