Outbound traffic has a price

Inbound traffic stays free, and each account's first 100 GiB out a month is free. Past it, what sandboxes send to the internet costs $0.02 per GB, fixed in each new sandbox's quote. Replies served through previews, custom domains and TCP ports, traffic to your own network, and trial sandboxes are not charged, and sandboxes made before today keep free traffic for their whole life. GET /v1/usage shows the month so far under outbound. See pricing.