Architecture Overview

This page sketches the high-level architecture of attn.
Details may evolve; this is a working map for developers and integrators.

1. Core components

Revenue Accounts
- Squads Safe / multisig vaults on Solana that receive protocol and creator revenues.
- Host routing logic for repayment, base yield, and withdrawals.
Position Engine
- Responsible for:
  - creating and tracking advances and credit line draws,
  - defining revenue share schedules and maturities,
  - interfacing with yield-stripping infra (PT/YT).
PT/YT Layer
- Implemented on Exponent Finance’s Standardised Yield (SY) fixed-income infra:
  - represent revenue-bearing positions as SY-like tokens,
  - strip into PT and YT,
  - expose them for vault accounting and potential secondary markets.
attnUSD Vault
- Holds stablecoins and PT/YT positions.
- Mints and burns attnUSD.
- Computes NAV and enforces portfolio limits.
Risk & Limits Engine
- Stores per-project and portfolio limits.
- Approves or rejects new positions based on risk data.
- Applies haircuts for pricing and NAV.
Offchain / Hybrid Services
- Monitoring:
  - revenue data feeds,
  - health checks on routes and programs.
- Governance and operations:
  - parameter changes,
  - manual interventions in emergencies.

Revenue in
- Protocol / creator configures fee switch / rewards to flow into a Revenue Account.
- Revenue Account reports balances and flows to the Position Engine and Risk Engine.
Position creation
- Project requests an advance or draw from a credit line.
- Risk Engine checks limits and parameters.
- Position Engine creates a new RBP and strips it into PT/YT via PT/YT Layer.
- attnUSD Vault (or another LP) purchases the YT leg; funds are sent to the project.
Repayment and yield
- Incoming revenues are split according to routing rules.
- Cashflows allocated to each open position are tracked and credited against YT.
- Vault NAV updates based on realised flows and updated marks.
Withdrawals and redemptions
- Projects withdraw unencumbered revenues from their Revenue Accounts.
- LPs deposit/withdraw from attnUSD, which adjusts vault holdings in stables and PT/YT.

Further diagrams and sequence charts can be added as the implementation solidifies.