Teams usually leave Twilio over per message billing or 10DLC registration, not over the API. These posts compare the two models honestly and show what a migration actually involves. Read the cost math first, then the migration steps.
Three costs push teams off Twilio. The per segment rate grows with every message you send. A rented number and carrier fees are billed on top of it. In the US, a 10DLC brand and campaign must be registered before traffic flows. The posts below put real numbers on each of these, with the date each price was checked.
The other half of the topic is the switch itself. One guide maps every Twilio concept to its textbee counterpart: credentials, the send call, the status callback and the inbound webhook. Others cover one time codes for a small app, sending to countries where Twilio rates are high, and running the gateway on your own server.
Start with the cost breakdown if price is the question. Start with the migration guide if you have already decided. The comparisons with Plivo, Vonage and Bird cover the cloud providers, for teams that need to stay on a rented number.