Settlement System

Traditional rollups lock capital and introduce:

• Multi-step withdrawal processes: Initiate → Wait → Release
• Multi-day fraud proof windows: Capital remains locked and unproductive

This design creates a poor experience for users, builders, and solvers.

Market-Based Settlement

Signet eliminates the complicated withdrawal process and unnecessary delays through swaps by:

1. Synchronized Block Production

• Identical timestamps ensure deterministic ordering
• Fork-choice rule maintains consensus alignment

2. Atomic Cross-Chain Execution

• Same-block finality
• Conditional transaction enforcement

3. Market-Driven Price Discovery

• Competitive filler ecosystem
• Real-time liquidity provision

Signet is the only chain to achieve same-block cross chain settlement and it starts with our synchronized block architecture.

Concurrent Block Production

This 1:1 coupling enables deterministic state transitions. Every Signet block corresponds to exactly one Ethereum block, eliminating timing discrepancies.

Order System Architecture

Orders express atomic intent through Permit2, enabling gasless authorization:

pub struct SignedOrder {
    pub permit: Permit2Batch,      // Single signature authorization
    pub outputs: Vec<Output>,      // Desired assets and destinations
}

pub struct Output {
    pub token: Address,            // Asset identifier
    pub amount: Uint<256, 4>,      // Precise amount
    pub recipient: Address,        // Destination address
    pub chainId: u32,             // Target chain
}

Order Lifecycle:

1. Creation: User signs intent with ~10 minute validity window
2. Discovery: Broadcast to transaction cache for filler evaluation
3. Execution: Atomic settlement within single block
4. Finalization: Immediate availability on destination chain

Settlement Mechanics: Inverted Execution

Signet’s approach to atomicity is in transaction ordering enforcement:

The OrderDetector enforces atomicity by validating that every order has corresponding fills before allowing transaction execution. This prevents partial settlements through deterministic state validation:

impl OrderDetector {
    fn validate_transaction(&self, tx: &Transaction) -> Result<(), Error> {
        // Check if transaction emits Order event
        if let Some(order) = self.detect_order(tx) {
            // Verify all outputs have corresponding fills
            for output in order.outputs {
                if !self.has_sufficient_fill(output) {
                    return Err(Error::InsufficientFill);
                }
            }
            // Consume fill amounts to prevent double-spending
            self.consume_fills(order.outputs);
        }
        Ok(())
    }
}

Key Benefits:

• Fill transactions must mine before Initiate transactions
• Failed fills result in automatic Initiate rejection
• No intermediate states or partial executions

Capital Efficiency

Traditional rollups lock capital for extended periods. Signet enables continuous deployment:

This enables strategies previously impossible on other chains:

1. Intra-Block Arbitrage

• Execute multiple trades within single 12-second block
• Compound returns through circular trading paths
• Eliminate sequential execution risk

2. Dynamic Inventory Management

• Real-time cross-chain balance optimization
• Just-in-time liquidity provision
• Zero idle capital

3. Multi-Order Aggregation

• Net positions across multiple orders
• Reduce transaction costs through batching
• Maximize capital efficiency per block

Bundle Construction

Fillers aggregate multiple orders into atomic execution bundles:

async fn construct_bundle(&self, orders: &[SignedOrder]) -> Result<SignetEthBundle> {
    // Aggregate orders by destination chain
    let aggregated = self.aggregate_by_chain(orders);

    // Sign fills for each destination
    let signed_fills = self.sign_fills(&aggregated).await?;

    // Build transaction sequence with proper ordering
    let txs = self.sequence_transactions(&signed_fills, orders).await?;

    // Extract cross-chain coordination data
    let host_fills = signed_fills.get(&ETHEREUM_CHAIN_ID);

    // Atomic bundle with deterministic execution
    Ok(SignetEthBundle {
        host_fills,     // Ethereum-side actions
        bundle: EthSendBundle {
            txs,        // Signet-side transactions
            block_number: self.target_block(),
            reverting_tx_hashes: vec![], // No reverts allowed
        },
    })
}

Error Handling:

• Invalid signatures → Bundle rejected pre-execution
• Insufficient liquidity → Fill transaction reverts
• Gas exhaustion → Entire bundle fails atomically

Market Efficiencies:

Multiple fillers evaluate each order simultaneously, creating competitive pricing:

• Multiple fillers evaluate each order simultaneously
• Competition drives spreads toward equilibrium
• Price discovery occurs every 12 seconds
• No single filler controls market pricing
• Capital availability across chains

Filler Infrastructure

Implement custom market-making strategies using the Signet SDK:

// Custom filler implementation
impl FillerStrategy for MyFiller {
    async fn evaluate_order(&self, order: &SignedOrder) -> Option<FillDecision> {
        // Implement custom pricing logic
        let profit_margin = self.calculate_margin(order)?;

        // Check inventory across chains
        let has_liquidity = self.check_inventory(order).await?;

        // Evaluate competition
        let competitive = self.estimate_win_probability(order);

        if profit_margin > self.min_margin && has_liquidity && competitive > 0.3 {
            Some(FillDecision::Accept)
        } else {
            None
        }
    }
}

• Gas cost optimization
• Inventory rebalancing costs
• Competition assessment
• Risk-adjusted profit margins

Protocol-Level Markets

Signet’s architecture embeds market mechanics at the protocol level:

Every application built on Signet is enabled with instant cross-chain settlement.

Cross-Chain Settlement Opportunities

Whether it’s building user applications, providing liquidity, or executing orders, every builder benefits from the speed of settlement to Ethereum:

• No asynchronous state risks between chain operations
• No wrapped token complexity or liquidity fragmentation
• No artificial constraints on capital deployment
• No settlement uncertainty affecting execution

Build with us

The best way to get started is with our docs or getting in touch if you have any questions.

Get Involved:

• Developer interest form
• Documentation feedback

Market Participants:

• Filler examples: Complete implementation patterns

Order System:

• Orders in Signet: Permit2 orders in Signet
• SDK primitives: Type-safe order handling

Bundle Construction:

• Atomic execution: Transaction sequencing tools
• Simulation framework: Pre-execution validation