Platform Architecture

The o2 Exchange is composed of:

• Sway Contracts: OnChain components that deliver all main functionality, from user access to order matching, most components work in a permissionless way.
• Data Layer: OffChain indexer, that indexes the pre-confirmation receipts, from the transactions executed on the contracts, and distributes rich data via REST and Websocket APIs.
• Executor Layer: This component forwards user actions to the Fuel Network, sponsoring gas for on-demand transactions. It does not apply any logic for batching or prioritizing transactions.
• User Interface Layer: The set of tools / UIs that facilitates the interaction with the other components.

graph TB
    subgraph "User Interface Layer"
        Web[Web Trading Interface]
        API[HTTP/WebSocket APIs]
        CLI[Developer CLI]
    end

    subgraph "Service Layer"
        subgraph "Read-Only"
            REST[REST]
            WS[WebSocket Service]
        end
        subgraph "Executor"
            Sponsor[Gas Sponsor]
            Upgrade[Order Book create/upgrade]
        end
        subgraph "Data Indexer"
            Indexer[Event Indexer]
        end
    end

    subgraph "Blockchain Layer"
        subgraph "Discovery logic"
            REG[Order Book Registry]
            TREG[Trading Account Registry]
        end

        subgraph "Proxy Contracts"
            TAP[Trading Account Proxy]
            OBP[Order Book Proxy]
        end

        subgraph "Core Logic"
            TA[Trading Accounts]
            OB[Order Books]
            Oracle[Upgrade Oracle]
        end
    end