Events & errors - Rondo

Events

Event	Carries
`OrderCreated`	Fixed orders. `buyAmount`, `feeBps`, and the oracle answer at creation
`PeggedOrderCreated`	A separate event — `premiumBps`, `minRate`, the answer
`OrderFilled`	taker · maker · sellToken · amountOut · amountIn · fee · `sellRemaining` after
`OrderCloseSkipped`	A batch close left an order open because its escrow could not be delivered
`OrderCancelled`	`by`, refunded amount and whether it was maker-initiated
`OrderExpiryClosed`	Distinct from cancel: maker, sweeper, refund

Errors

Creation

Error	Cause
`InvalidTokenPair`	`buyToken` is not the counter-token, or equals `sellToken`
`UnsupportedToken`	Neither token in the selected base/USDT market
`BelowMinOrderAmount`	Under `minOrderAmount[sellToken]`
`InvalidExpiry` · `DurationTooLong`	Deadline already past, or beyond `maxOrderDuration`
`PriceOutOfBand`	Fixed order priced outside `±bandBps`
`PremiumTooHigh`	Above `maxPremiumBps`
`ZeroMakerFloor` · `FloorAboveMarket`	Pegged floor missing, or set above the current rate
`FloorTooLoose`	Pegged floor is farther below the current settled rate than `bandBps` allows

Filling

Error	Cause
`OrderNotOpen` · `OrderExpired`	Already closed, or past its deadline
`ExceedsRemaining`	Asked for more than the order holds
`BelowMinFill`	A partial fill below the minimum, on an order still above it
`SlippageExceeded`	`amountIn` exceeded the taker’s `maxAmountIn`
`BelowMakerFloor`	The settled rate fell under the maker’s `minRate`
`TakerNotWhitelisted`	The caller lacks `TAKER_ROLE` — reachable only while `takerWhitelistEnabled` is on

Oracle

Error	Cause
`InvalidOracleAnswer` · `StaleOracle`	Non-positive answer, or latest observation older than `maxOracleAge`
`OracleTwapUnavailable`	The five-minute average could not be produced with at least five observations

Safety

Error	Cause
`UnexpectedTransferAmount`	A token delivered less than requested — the fee-on-transfer guard
`NotOrderMaker` · `ZeroAddress` · `ZeroAmount`	Caller or argument problems

OpenZeppelin access-control, pause and reentrancy guards can also revert, as can any selected base token or USDT during transfer / transferFrom. Those are dependency errors rather than Rondo-specific custom errors; do not treat this table as an exhaustive list of every byte sequence a transaction may return.