Protocol
A cluster, secured by quorum, closed cooperatively.
Every Coalesce cluster moves through the same five stages, from group formation to cooperative close. Nothing here requires a server or coordinator at any point. For the full mechanics (why each stage is safe), see the Concepts docs.
- 01
Bootstrap a cluster
Every member runs bootstrap with the same peer list. Identity bundles are exchanged over authenticated, pubkey-pinned connections. No private key ever crosses the wire.
- 02
Dealerless keygen
Any member types keygen. The group key is generated distributed-ly, so no machine, including any operator's, ever holds the full key.
- 03
Fund the cluster
Every member independently runs dfund with whatever amount they want to commit. All of it lands in one joint funding transaction, so opening a cluster of any size takes a single on-chain transaction, not one per member and not one per pair.
- 04
Transact off-chain
Members send and receive off-chain with send and bal. Checkpoints finalize automatically to lock in payments; propose forces one early.
- 05
Close cooperatively
Any member types coopclose. Everyone co-signs one closing transaction, the full settlement prints before broadcasting, and the cluster settles on-chain.
Security Model
What "non-custodial" means here, precisely.
No server, no coordinator
Every node holds only its own key share and wallet. Nothing runs centrally.
Dealerless keygen
The group key is generated distributed-ly. No machine ever holds the full key.
Quorum safety
Funds stay safe as long as more than two-thirds of members are honest. A single honest node can always recover its own money.
One transaction opens the whole cluster
Every member's contribution is an input to a single joint funding transaction, so opening a cluster of any size takes one on-chain transaction, not one channel per pair.
On-chain open & close only
That one funding transaction and one closing transaction are the only times the cluster touches Bitcoin L1. Every payment in between is off-chain.
Privacy
Bitcoin settles the cluster, not every payment inside it.
A payment between members doesn't automatically become its own Bitcoin transaction; only funding and closing ever touch the chain. The blockchain sees the cluster's shared state open and settle, not a permanent record of who paid whom in between. This isn't a claim that Bitcoin transactions become untraceable: funding, closing, amounts, and timing are still visible on-chain. For the precise version of that claim, see Concepts: Privacy.