CTFExchange

CTFExchange is a Polymarket-compatible order-matching contract that settles trades against ConditionalTokens. PredictStreet deploys it with the quadratic taker-fee formula fee = k × P × (1−P) × outcomeTokens. See Fees for the math.

Key entry points

Function	Caller	Purpose
`fillOrder(Order, fillAmount)`	`onlyOperator`	Direct fill against a resting order
`matchOrders(takerOrder, makerOrders[], takerFillAmount, makerFillAmounts[])`	`onlyOperator`	Single-taker batch
`batchMatchOrders(takerOrders[], makerOrders[][], takerFillAmounts[], makerFillAmounts[][])`	`onlyOperator`	Multi-taker batch — per-taker reverts caught and emitted as `MatchFailed` so the rest of the batch still settles
`cancelOrders(Order[])`	signer of each order	Cancel on-chain
`registerToken(uint256 token0, uint256 token1, bytes32 conditionId)`	`onlyAdmin`	Register a new market
`pauseTrading()` / `unpauseTrading()`	`onlyAdmin`	Emergency halt
`pauseUser(address, uint256 blocks)`	`onlyAdmin`	Block a specific user
`pauseMarket(bytes32 conditionId)`	`onlyAdmin`	Block a specific market
`setVaultFactory(address)`	`onlyAdmin`	Wire the VaultFactory
`addOperator(address)`	`onlyAdmin`	Whitelist an operator key

Fee formula

// BUY: fee charged in outcome tokens
fee_tokens = feeRateBps × (1 − price) × outcomeTokens / BPS_DIVISOR;

// SELL: fee charged in collateral
fee_collateral = feeRateBps × price × (1 − price) × outcomeTokens / (BPS_DIVISOR × ONE);

Cap: feeRateBps ≤ MAX_FEE_RATE_BIPS (1000).

Events

event OrderFilled(
    uint64 seq,
    bytes32 indexed orderHash,
    address indexed maker,
    address taker,
    uint256 makerAssetId,
    uint256 takerAssetId,
    uint256 makerAmountFilled,
    uint256 takerAmountFilled,
    uint256 fee
);

event OrdersMatched(...);
event OrderCancelled(uint64 seq, bytes32 indexed orderHash);
event FeesWithdrawn(uint64 seq, address indexed token, address to, uint256 amount);

Security invariants

Signature replay impossible — every filled order’s hash stored in orderStatus[hash].isFilledOrCancelled.
Maker authority cryptographic — maker field verified against signer via vaultFactory.vaultOf(signer) (VAULT) or equality (EOA).
Admin can pause but not seize — no admin function transfers user funds.
Operator rotatable — removeOperator(address) disables compromised key.

`MatchFailed` reason codes

When batchMatchOrders catches a per-leg revert, the reason bytes are the 4-byte selector of the original custom error. Common ones:

Selector	Custom error	Cause
`0xc56873ba`	`OrderExpired()`	A maker or taker order’s `expiration` is in the past at execution time. Most common with stale resting LIMITs whose TTL elapsed between match (off-chain) and submit (on-chain).
`0xb52e0fec`	`OrderFilledOrCancelled()`	The order’s hash is already marked filled or cancelled on-chain (replay or duplicate match).
`0x70a52d24`	`MismatchedTokenIds()`	Taker and maker outcome tokens don’t form a valid binary pair.
`0xc7e63d99`	`NotCrossing()`	The proposed prices don’t cross.

Decode the bytes with cast 4byte 0x<selector> or by computing bytes4(keccak256(<errorSig>)).

To avoid OrderExpired() settlement failures, sign orders with expiration = 0 (no on-chain expiry — the contract skips the block.timestamp >= expiration check entirely). UIs that need a hard TTL should set it well above worst-case settlement latency.

Source

Paste 0x4074c225b296E1E556c565B0C3Ddba305E63E7c4 on Blockscout for verified source + ABI.

Getting Started

Authentication

Vaults

Deposits

Trading

Events & Tags

Markets

Portfolio

Withdrawals

WebSocket

Settlement & Oracle

On-chain Contracts

Partners

Errors

Key entry points

Fee formula

Events

Security invariants

`MatchFailed` reason codes

Source

​Key entry points

​Fee formula

​Events

​Security invariants

​MatchFailed reason codes

​Source

Key entry points

Fee formula

Events

Security invariants

`MatchFailed` reason codes

Source