feat: mev_computeBundleGas

title: Bundle Gas Computation RPC Method
description: A new RPC method for calculating adjusted gas prices for transaction bundles

mev_computeBundleGas/README.md

@@ -0,0 +1,202 @@
+---
+eip: TBD
+title: Bundle Gas Computation RPC Method
+description: A new RPC method for calculating adjusted gas prices for transaction bundles
+author: [Author Name] (@github)
+discussions-to: TBD
+status: Draft
+type: Standards Track
+category: Interface
+created: 2024-12-16
+requires: 1559, 4337
+---
+
+## Abstract
+
+This EIP introduces a new JSON-RPC method `eth_computeBundleGas` that calculates the adjusted gas price for a bundle of transactions, taking into account gas usage, original gas prices, and direct coinbase transfers. This method is particularly useful for MEV-aware applications and bundle builders.
+
+## Motivation
+
+Transaction bundles have become increasingly important with the rise of MEV extraction and complex DeFi interactions. Currently, there is no standardized way to:
+
+1. Calculate the effective gas price for a bundle of transactions
+2. Account for direct coinbase payments in bundle pricing
+3. Determine the total value extraction from a bundle
+
+## Specification
+
+The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.
+
+### JSON-RPC Method Definition
+
+#### eth_computeBundleGas
+
+Computes the adjusted gas price for a bundle of transactions, accounting for all gas expenditure and coinbase transfers.
+
+##### Parameters
+
+1. `Array of Object` - The bundle of transactions
+    - Each object MUST contain:
+        - `hash`: `DATA` - Transaction hash
+        - `gasUsed`: `QUANTITY` - Gas used by the transaction
+        - `gasPrice`: `QUANTITY` - Original gas price
+        - `coinbaseTransfers`: `QUANTITY` - Value transferred to coinbase
+
+##### Returns
+
+`Object` - The bundle gas calculation results
+- `adjustedGasPrice`: `QUANTITY` - The computed adjusted gas price for the bundle
+- `totalGasUsed`: `QUANTITY` - Total gas consumed by the bundle
+- `totalValue`: `QUANTITY` - Total value including gas costs and coinbase transfers
+- `perTxMetrics`: `Array of Object` - OPTIONAL. Detailed metrics for each transaction
+  - `effectiveGasPrice`: `QUANTITY` - Individual transaction's effective gas price
+  - `valueContribution`: `QUANTITY` - Transaction's contribution to total value
+
+##### Implementation Requirements
+
+Clients implementing this method MUST:
+
+1. Calculate bundle metrics using the following formulas:
+   ```
+   totalGasUsed = sum(tx.gasUsed for tx in bundle)
+   totalGasCost = sum(tx.gasUsed * tx.gasPrice for tx in bundle)
+   totalCoinbaseTransfers = sum(tx.coinbaseTransfers for tx in bundle)
+   adjustedGasPrice = (totalGasCost + totalCoinbaseTransfers) / totalGasUsed
+   ```
+
+2. Validate the bundle:
+   - Ensure at least one transaction is present
+   - Verify all required fields are present for each transaction
+   - Check that all numerical values are valid and non-negative
+
+3. Handle edge cases:
+   - Return an error if totalGasUsed is zero
+   - Handle arithmetic overflow in calculations
+   - Properly round results when division is not exact
+
+##### Example
+
+Request:
+```json
+{
+  "id": 1,
+  "jsonrpc": "2.0",
+  "method": "eth_computeBundleGas",
+  "params": [[
+    {
+      "hash": "0x123...",
+      "gasUsed": "0x5208",
+      "gasPrice": "0x4a817c800",
+      "coinbaseTransfers": "0x0"
+    },
+    {
+      "hash": "0x456...",
+      "gasUsed": "0x7530",
+      "gasPrice": "0x4a817c800",
+      "coinbaseTransfers": "0x2386f26fc10000"
+    }
+  ]]
+}
+```
+
+Response:
+```json
+{
+  "id": 1,
+  "jsonrpc": "2.0",
+  "result": {
+    "adjustedGasPrice": "0x4d853c800",
+    "totalGasUsed": "0xc738",
+    "totalValue": "0x2386f26fc10000",
+    "perTxMetrics": [
+      {
+        "effectiveGasPrice": "0x4a817c800",
+        "valueContribution": "0x1234"
+      },
+      {
+        "effectiveGasPrice": "0x4f817c800",
+        "valueContribution": "0x5678"
+      }
+    ]
+  }
+}
+```
+
+### Security Considerations
+
+1. Bundle Size Limits
+   - Implementations MUST set a maximum bundle size
+   - Implementations SHOULD limit total computation time
+
+2. Numerical Handling
+   - All arithmetic operations MUST handle overflow conditions
+   - Implementations SHOULD use appropriate precision for calculations
+
+3. Resource Protection
+   - Methods MUST implement rate limiting
+   - Implementations SHOULD cache results for identical bundles briefly
+
+4. Input Validation
+   - All transaction parameters MUST be validated
+   - Implementations SHOULD check for realistic value ranges
+
+### Backwards Compatibility
+
+This EIP introduces a new method and does not modify existing behavior. No backwards compatibility issues are present.
+
+## Rationale
+
+The design choices in this specification are motivated by several factors:
+
+1. Including per-transaction metrics allows for detailed analysis of bundle composition
+
+2. Separating coinbase transfers from gas costs provides transparency into MEV extraction
+
+3. The comprehensive validation requirements ensure consistent behavior across clients
+
+4. The method name clearly indicates its purpose while following Ethereum naming conventions
+
+## Reference Implementation
+
+```go
+func (s *PublicBlockChainAPI) ComputeBundleGas(bundle []BundleTransaction) (*BundleGasResult, error) {
+    if len(bundle) == 0 {
+        return nil, errors.New("empty bundle")
+    }
+
+    totalGasUsed := new(big.Int)
+    totalGasCost := new(big.Int)
+    totalCoinbaseTransfers := new(big.Int)
+    perTxMetrics := make([]TxMetrics, len(bundle))
+
+    for i, tx := range bundle {
+        // Calculate gas cost
+        gasCost := new(big.Int).Mul(tx.GasUsed, tx.GasPrice)
+        totalGasCost.Add(totalGasCost, gasCost)
+
+        // Add gas used
+        totalGasUsed.Add(totalGasUsed, tx.GasUsed)
+
+        // Add coinbase transfers
+        totalCoinbaseTransfers.Add(totalCoinbaseTransfers, tx.CoinbaseTransfers)
+
+        // Calculate per-tx metrics
+        perTxMetrics[i] = calculateTxMetrics(tx, gasCost)
+    }
+
+    // Calculate adjusted gas price
+    adjustedGasPrice := new(big.Int).Add(totalGasCost, totalCoinbaseTransfers)
+    adjustedGasPrice.Div(adjustedGasPrice, totalGasUsed)
+
+    return &BundleGasResult{
+        AdjustedGasPrice:    (*hexutil.Big)(adjustedGasPrice),
+        TotalGasUsed:        (*hexutil.Big)(totalGasUsed),
+        TotalValue:          (*hexutil.Big)(totalCoinbaseTransfers),
+        PerTxMetrics:        perTxMetrics,
+    }, nil
+}
+```
+
+## Copyright
+
+Copyright and related rights waived via [CC0](https://creativecommons.org/publicdomain/zero/1.0/).