Skip to main content
Four stakeholder roles commission computations, operate infrastructure, delegate stake, and recover MPC eXecution Environment (MXE) keys:
  • Computation Customers: Create MXEs, define computations, and pay execution charges.
  • Arx Operators: Run Arx nodes that execute encrypted computations in Clusters.
  • Third-Party Delegators: Delegate stake to Arx nodes and receive a share of their rewards.
  • Recovery Peers: Support key recovery for a specific MXE and receive a separate stake-weighted reward share.

​
Computation customers

Computation Customers integrate Arcium into a Solana program and commission computations:
  • Create an MPC eXecution Environment (MXE): Bind the MXE to a Cluster and define how its Solana program uses computation results.
  • Define computations: Compile Arcis circuits and register their source and CU amount.
  • Commission execution: Provide inputs, callbacks, and an optional priority price. Higher priority improves queue position; applications handle expiry through their lifecycle logic.
Persistent state used by the onchain integration lives in Solana accounts. The Arcium program coordinates computation accounts and callbacks, while encrypted execution occurs offchain.

​
Arx operators

Arx Operators run Arx nodes that execute computations with other members of a Cluster. Their responsibilities include:
  • Register the Arx node: Declare its identity and CU capacity. Stake requirements govern activation and Cluster eligibility.
  • Stake and join a Cluster: Meet the activation and Cluster-specific stake requirements, then accept an authority’s invitation.
  • Protect key material: Secure the host and the MPC key shares stored by the Arx node. Customers evaluate hosting controls when selecting Cluster members.
Revenue streams:
  1. Primary stake rewards: The operator receives the portion attributed to its primary stake.
  2. Delegation fees: The operator receives its configured percentage fee from delegated rewards.
Primary and delegated stake also contribute to the Arx node’s leader weight.

​
Third-party delegators

Third-Party Delegators contribute stake to an Arx node. They receive a pro-rata share of its rewards after the Node Operator’s fee. Delegators choose operators using offchain information such as operating history and security practices. Program rewards follow stake, while reputation informs delegation decisions.

​
Recovery peers

Recovery Peers participate when an MXE authority initiates key recovery or migration. Each MXE has its own Recovery Peers, separate from the Cluster’s Arx nodes. Recovery Peer stake is bound exclusively to the role: the same stake account cannot also back an Arx node. This binding is enforced onchain by the staking program. Rewards: When epoch settlement is current, 20% of the computation reward basis accrues to the MXE’s Recovery Peer pot. Settlement records each peer’s stake-weighted claim. During migration, Recovery Peers help transfer the MXE’s key material to its destination Cluster. The MXE authority initiates migration when the application needs to change Clusters.