The model
Lark Cloud is a flat monthly base price that includes an allotment of storage and bandwidth. Go past the included amounts and usage is metered per GB. There are no per-operation charges, no per-seat charges, and no charge for concurrent connections. Self-hosting is free. Lark is open source under AGPL v3, with no usage limits.Bandwidth
Bandwidth is outbound traffic only: the bytes Lark sends down to your clients. That includes query results, subscription events, and REST API responses. Uploads (your writes) are free. Because every subscriber receives a copy of each event, fan-out is what drives bandwidth. A 1 KB write to a path with 100 subscribers sends roughly 100 KB of egress, not 1 KB. Lark’s delta-based subscriptions keep this efficient by sending only what changed, not the full value.Storage
Storage is your database’s on-disk size, sampled daily and billed per GB-month. Storing 10 GB for three days costs a fraction of storing 10 GB all month. Deleting data lowers your bill from the next daily sample onward.Volatile bandwidth
Egress from volatile paths (fire-and-forget data like cursors, positions, and game state) is billed at 1/5th the standard bandwidth rate. 10 GB of volatile egress counts as 2 GB against your bandwidth usage. This discount is why Lark works for high-frequency multiplayer sync. A game streaming 20Hz position updates to every player generates a lot of egress, and volatile pricing keeps that affordable. Volatile data is also never persisted, so it doesn’t count toward storage.Concurrent connections
Concurrent connections (CCU) are a plan limit, not a billed line item. You never pay per connection. If you’re running 10k+ peak CCU, get in touch about an enterprise plan with volume discounts.Tracking your usage
Your project dashboard shows current bandwidth, storage, and CCU against your plan limits, with warnings as you approach them. See Monitoring for details.Questions about pricing or billing? Reach out at team@lark.sh.