Contract Interface Reference

Public functions, error codes, and storage keys for settlement-verifier

Public Functions

initialize

Initializes contract state. Can only be invoked once.

pub fn initialize(
    env: Env,
    admin: Address,
    fee_recipient: Address,
    fee_bps: u32
) -> Result<(), Error>

• admin: Account authorized to update fee configs and protocol settings.
• fee_recipient: Account that collects basis point protocol fees.
• fee_bps: Protocol fee in basis points (max 1,000 = 10%).

---

settle_payment

Executes an atomic transfer from payer to merchant, deducting the protocol fee.

pub fn settle_payment(
    env: Env,
    payer: Address,
    merchant: Address,
    token: Address,
    amount: i128,
    nonce: u64,
    valid_until: u64
) -> Result<i128, Error>

• Reverts with Error::InvalidNonce if nonce != current_nonce + 1.
• Reverts with Error::ExpiredSignature if env.ledger().timestamp() > valid_until.
• Invokes token::Client::new(&env, &token).transfer(...) atomically.
• Emits SettlementReceipt event.
• Returns the net amount transferred to the merchant (i128).

---

verify_and_split

Splits a payment across multiple recipients according to basis points.

pub fn verify_and_split(
    env: Env,
    payer: Address,
    token: Address,
    amount: i128,
    recipients: Vec<(Address, u32)>,
    nonce: u64
) -> Result<(), Error>

• Enforces that the sum of recipient basis points plus protocol fee equals 10,000 (100%).
• Atomically transfers each recipient’s share.

---

Read Views

pub fn get_nonce(env: Env, account: Address) -> u64
pub fn get_admin(env: Env) -> Address
pub fn get_fee_config(env: Env) -> (u32, Address)

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Error Codes (#[contracterror])

Code	Variant	Reason
1	AlreadyInitialized	Attempted to re-initialize an already configured contract
2	NotInitialized	Function called before contract initialization
3	Unauthorized	Caller lacks admin authorization
4	InvalidNonce	Payer nonce did not match expected monotonic value
5	ExpiredSignature	Current ledger timestamp exceeds valid_until
6	InvalidAmount	Payment amount is zero or negative
7	InvalidFeeBps	Fee BPS exceeds maximum allowed threshold
8	TransferFailed	Underlying Stellar Asset Contract transfer failed