bridge-monitor: capture execution-cost metrics

benchmarks/bridge-execution-latency.yml

@@ -56,6 +56,7 @@ methodology:
   - "Outcome classification: settled (funds received), reverted or refunded (capital returned to source), or errored (never broadcast). Only settled transactions contribute to the latency distribution; reverts and refunds count against the success rate."
   - "Region: EU-West only at present. The execution node runs a single wallet, so a second origin would race the same inventory; additional origins are not planned for the execution loop."
   - "Cohort: Mobula, Relay and LI.FI. deBridge is quote-only in this loop. Providers without a symmetric route on all three legs are excluded so the triangle conserves."
+  - "Cost metrics captured per real execution (beyond latency and success): realized output on-chain, execution slippage vs the quote (realized fee minus quote-projected fee), our own on-chain gas paid (approve + deposit, measured as source-chain native balance delta), and the refund rate split from hard-fail rate. These surface the true all-in cost and the gap between a quote and what actually settles."
 
 findings:
   - "{{name:mobula}} settles at {{p50:mobula}} (p50, broadcast to funds received) with a {{success:mobula}} success rate over the last 24 hours."

harnesses/bridge-monitor/cmd/monitor/executor.go

@@ -41,6 +41,7 @@ type ExecutionResult struct {
 	E2ELatencyMs       int64 // Time from quote start to funds received
 	Success            bool
 	Reverted           bool
+	Refunded           bool // subset of Reverted: provider returned capital (status "refunded")
 	Error              error
 	QuoteFeeUSD        float64 // Fee from quote
 	ActualFeeUSD       float64 // Actual fee paid (input - output)
@@ -55,6 +56,7 @@ type ExecutionResult struct {
 	FeesPercent float64
 	CostUSD     float64
 	OutputUSD   float64 // What landed on destination (the fill)
+	ExecGasUSD  float64 // Our on-chain gas paid (approve + deposit), source native delta
 }
 
 // Executor handles the execution loop
@@ -374,6 +376,15 @@ func (e *Executor) executeOnBridge(bridge string, route TestRoute, amount, amoun
 		log.Printf("    ⚠️  pre-execution balance read failed (%v) — falling back to quote-projected fill", preBalErr)
 	}
 
+	// Source-chain native balance before execution, to measure the real gas we
+	// pay (approve + deposit) as the pre-minus-post delta. Single-flight (execMu)
+	// guarantees no other tx moves it during this one leg.
+	srcOwner := e.walletManager.EVMAddress
+	if route.FromChain == "Solana" {
+		srcOwner = e.walletManager.SolanaAddress
+	}
+	preNativeUSD, preNativeErr := e.txExecutor.nativeBalanceUSD(route.FromChain, srcOwner)
+
 	// PHASE 1: Get quote with TX data
 	quoteStart := time.Now()
 	var txHash string
@@ -434,6 +445,15 @@ func (e *Executor) executeOnBridge(bridge string, route TestRoute, amount, amoun
 		}
 	}
 
+	// Real gas we paid this leg = source native balance delta (approve + deposit).
+	if preNativeErr == nil {
+		if postNativeUSD, nerr := e.txExecutor.nativeBalanceUSD(route.FromChain, srcOwner); nerr == nil {
+			if g := preNativeUSD - postNativeUSD; g > 0 {
+				result.ExecGasUSD = g
+			}
+		}
+	}
+
 	result.FeesUSD = result.ActualFeeUSD
 	if amountUSD > 0 {
 		result.FeesPercent = (result.ActualFeeUSD / amountUSD) * 100
@@ -618,6 +638,7 @@ func (e *Executor) executeMobula(route TestRoute, amount float64, quoteStart tim
 		result.ActualFeeUSD = result.QuoteFeeUSD
 	} else if status.Status == "refunded" {
 		result.Reverted = true
+		result.Refunded = true
 		log.Printf("    [mobula] ⚠️ Transaction was refunded!")
 	}
 
@@ -755,6 +776,7 @@ func (e *Executor) executeRelay(route TestRoute, rawUnits string, quoteStart tim
 		result.ActualFeeUSD = result.QuoteFeeUSD
 	} else if status.Status == "refunded" {
 		result.Reverted = true
+		result.Refunded = true
 		log.Printf("    [relay] ⚠️ Transaction was refunded!")
 	}
 
@@ -886,6 +908,7 @@ func (e *Executor) executeLiFi(route TestRoute, rawUnits string, quoteStart time
 		result.ActualFeeUSD = result.QuoteFeeUSD
 	} else if status.Status == "refunded" || status.Status == "failed" {
 		result.Reverted = true
+		result.Refunded = status.Status == "refunded"
 		log.Printf("    [lifi] ⚠️ Transaction was refunded/failed!")
 	}
 
@@ -925,18 +948,29 @@ func (e *Executor) recordExecutionMetrics(result *ExecutionResult) {
 		bridgeReverts.WithLabelValues(labels...).Inc()
 		bridgeConsecutiveFailures.WithLabelValues(result.Bridge, e.region).Inc()
 	}
+	if result.Refunded {
+		bridgeRefunds.WithLabelValues(labels...).Inc()
+	}
 	if result.Error != nil {
 		bridgeErrors.WithLabelValues(append(labels, "execution_failed")...).Inc()
 		if !result.Reverted {
 			bridgeConsecutiveFailures.WithLabelValues(result.Bridge, e.region).Inc()
 		}
 	}
 
-	// Record fees
+	// Record fees + the new execution-cost metrics
 	bridgeFeesUSD.WithLabelValues(labels...).Set(result.ActualFeeUSD)
 	if result.AmountUSD > 0 {
 		bridgeFeesPercent.WithLabelValues(labels...).Set((result.ActualFeeUSD / result.AmountUSD) * 100)
 	}
+	if result.OutputUSD > 0 {
+		bridgeRealizedOutputUSD.WithLabelValues(labels...).Set(result.OutputUSD)
+	}
+	// Execution slippage vs quote = realized fee - quote-projected fee.
+	bridgeQuoteSlippageUSD.WithLabelValues(labels...).Set(result.ActualFeeUSD - result.QuoteFeeUSD)
+	if result.ExecGasUSD > 0 {
+		bridgeExecGasUSD.WithLabelValues(labels...).Set(result.ExecGasUSD)
+	}
 }
 
 // getSourceTokenName returns the source token name for balance checking (legacy - fallback)

harnesses/bridge-monitor/cmd/monitor/metrics.go

@@ -57,6 +57,35 @@ var (
 		Help: "Total number of reverted/refunded bridge transactions",
 	}, []string{"bridge", "from_chain", "to_chain", "from_token", "to_token", "amount_usd", "region", "chain"})
 
+	// Refund counter: subset of reverts where the bridge returned capital to
+	// source (status "refunded") rather than an on-chain revert. Lets us split
+	// refund-rate from hard-fail-rate (reverts minus refunds).
+	bridgeRefunds = promauto.NewCounterVec(prometheus.CounterOpts{
+		Name: "bridge_refunds_total",
+		Help: "Bridge transactions the provider refunded (capital returned to source)",
+	}, []string{"bridge", "from_chain", "to_chain", "from_token", "to_token", "amount_usd", "region", "chain"})
+
+	// Realized output that actually landed on the destination (on-chain fill).
+	bridgeRealizedOutputUSD = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Name: "bridge_realized_output_usd",
+		Help: "USD value that actually landed on the destination chain (realized fill)",
+	}, []string{"bridge", "from_chain", "to_chain", "from_token", "to_token", "amount_usd", "region", "chain"})
+
+	// Execution slippage vs the quote: realized fee minus quote-projected fee.
+	// Positive means the execution cost more than the quote promised.
+	bridgeQuoteSlippageUSD = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Name: "bridge_quote_slippage_usd",
+		Help: "Realized fee minus quote-projected fee (execution cost above what the quote promised)",
+	}, []string{"bridge", "from_chain", "to_chain", "from_token", "to_token", "amount_usd", "region", "chain"})
+
+	// Our own on-chain gas cost for this execution (approve + deposit), measured
+	// as the source-chain native balance delta. This is the cost WE bear, on top
+	// of the bridge's own fee, for the true all-in cost.
+	bridgeExecGasUSD = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Name: "bridge_exec_gas_usd",
+		Help: "On-chain gas we paid (approve + deposit), source-chain native balance delta in USD",
+	}, []string{"bridge", "from_chain", "to_chain", "from_token", "to_token", "amount_usd", "region", "chain"})
+
 	// Error counter
 	bridgeErrors = promauto.NewCounterVec(prometheus.CounterOpts{
 		Name: "bridge_errors_total",

harnesses/bridge-monitor/cmd/monitor/nearintents_exec.go

@@ -303,6 +303,7 @@ func (e *Executor) executeNearIntents(route TestRoute, amountUSD float64, rawUni
 		result.Success = true
 	case "REFUNDED", "FAILED":
 		result.Reverted = true
+		result.Refunded = status == "REFUNDED"
 	default:
 		// Timed out in PROCESSING/PENDING: terminal-ambiguous. Leave Success
 		// false with the TxHash set so the caller treats it as in-flight.

harnesses/bridge-monitor/cmd/monitor/tx_executor.go

@@ -599,6 +599,29 @@ func (tx *TxExecutor) getRelayStatus(requestID string) (*BridgeStatus, error) {
 }
 
 // Close closes all connections
+
+// nativeBalanceUSD returns the native-token (ETH/SOL) balance of ownerAddr on
+// chain, valued in USD. Used to measure the real gas we pay for an execution
+// as the source-chain native balance delta (pre - post).
+func (tx *TxExecutor) nativeBalanceUSD(chain, ownerAddr string) (float64, error) {
+	if strings.EqualFold(chain, "Solana") {
+		k, err := solana.PublicKeyFromBase58(ownerAddr)
+		if err != nil {
+			return 0, err
+		}
+		lamports, err := tx.solanaNativeBalance(k)
+		if err != nil {
+			return 0, err
+		}
+		return rawToFloat(lamports, 9) * TokenPriceUSD("SOL", 150), nil
+	}
+	wei, err := tx.evmNativeBalance(chain, common.HexToAddress(ownerAddr))
+	if err != nil {
+		return 0, err
+	}
+	return rawToFloat(wei, 18) * TokenPriceUSD("ETH", 3600), nil
+}
+
 func (tx *TxExecutor) Close() {
 	if tx.baseClient != nil {
 		tx.baseClient.Close()