Introduction

Structured notes, settled on-chain.

Note Systems is a standalone protocol for autocallable barrier notes on Robinhood Chain Stock Tokens. A note buyer deposits USDG and earns a coupon at every official close where the stock holds above a barrier. A stock holder posts Stock Tokens, pays those coupons, and receives a knock-in put struck at the initial price. Every payment is escrowed in advance. There are no liquidations and no margin calls.

Open app Read the worked example

What these docs cover

OverviewWhat the protocol does, why it exists, and who each leg is designed for. ConceptsAutocallables, barriers, observations, physical settlement and coupon discovery, with payoff diagrams. ProtocolSeries lifecycle, the COUPON and SHIELD legs, the escrow invariant, oracle rules, fees and automation. TokenNOTE, sNOTE, Bonds, the treasury floor, the Buyback Auction and the Desk vault. RiskMarket, oracle, issuer, smart contract and regulatory risk, stated plainly. SecurityTesting methodology, invariant suites, static analysis, bug bounty and audit status. DevelopersSolidity interfaces, ERC-1155 id scheme, events and the contract address table. GovernanceRoles, the timelock multisig, the guardian, and which parameters can change.

The protocol in one table

Component	Role	Denomination
Series	One autocallable barrier note on one Stock Token with a fixed observation schedule	Parameters in bps and 1e8 prices
COUPON	Note-buyer leg. Deposits USDG, earns coupons, wears the downside below the barrier at maturity	ERC-1155, 1 unit = 1 USDG matched notional
SHIELD	Stock-holder leg. Posts Stock Tokens and prefunds coupons, receives a down-and-in put struck at S0	ERC-1155, 1 unit = 1 USDG matched notional
NoteCore	Escrow, matching, observation, settlement and claims	USDG and Stock Tokens
OracleAdapter / MarketCalendar	Reads the Chainlink-style feed only at official US equity closes	Prices in 1e8
Desk	ERC-4626 USDG vault, counterparty of last resort for unmatched SHIELD supply, under hard caps	USDG
NOTE / sNOTE	Protocol token and its ERC-4626 staking vault; rewards are bought-back NOTE, streamed over 7 days	NOTE, 18 decimals
BondDepository, Treasury, RevenueRouter	Capital formation, the reserve-value floor and the continuous Dutch-auction buyback	USDG, Stock Tokens, COUPON legs

How to read the numbers

Every quantitative statement in these docs carries one of three labels.

• fact Protocol constants and formulas taken from the protocol specification. Verifiable on-chain once contracts are deployed.
• illustrative Example values chosen to make the maths concrete. They are not forecasts and not defaults.
• tbd Values not yet fixed (addresses, audit reports, governance parameters set at launch).

Defaults quoted from the specification (for example barrier 65%, coupon fee 15%) are facts about the specification, not promises about any particular series. Governance may set different values at series creation.

Status

Contracts are specified and under implementation. They are not deployed. The app runs in Preview mode against typed mock data whose shapes mirror INoteCore. There are no third-party audits yet. See Audits and Addresses.

Stock Tokens are issued by Robinhood Assets and are not available to US persons; they are also restricted in the UK, Canada and Switzerland (see Robinhood docs). Note Systems inherits those restrictions. See Regulatory risk.