OP Mainnet batches users' transactions and submits them to Ethereum, paying a share of the transaction fees to Ethereum validators (expense).

OP Mainnet is an L2 smart contract platform for decentralized applications on Ethereum. OP Mainnet was founded by Jinglan Wang, Karl Floersch & Kevin Ho and launched in 2021.

Optimism team & investors own and govern the protocol. Optimism’s investors include Paradigm, a16z, IDEO CoLab Ventures, etc.

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OP Mainnet

# OP Mainnet Median transaction fee Methodology

## 1. Overview

The Optimism median transaction fee metric measures the median cost of executing transactions on the Optimism network on a daily basis. This metric captures the middle point of transaction fee distribution, providing insight into typical transaction costs for users. The calculation combines both Layer 1 (L1) and Layer 2 (L2) fee components that are inherent to Optimism's rollup architecture, where transactions are processed on L2 but ultimately settled on Ethereum L1.

## 2. Data sources

- **Optimism transaction records**: Complete transaction data from the Optimism blockchain including gas usage, gas prices, and L1-specific fee components
- **End-of-day token price feeds**: ETH/USD price data for converting fee amounts to USD values
- **Token metadata**: WETH contract information (`0x4200000000000000000000000000000000000006`) used as the reference token for fee denomination

## 3. Step-by-step calculation

### Component A: Transaction fee extraction
- **Purpose**: Extract all Optimism transactions and prepare gas fee calculation components
- **Logic**: Retrieve all distinct transactions from Optimism blockchain data, focusing on gas-related fields including `gas_used_amount`, `gas_price`, `receipt_l1_gas_used`, `receipt_l1_gas_price`, `receipt_l1_fee`, and `receipt_l1_fee_scalar`. Each transaction is associated with the WETH token address since fees are paid in ETH. All numeric values are cast to high-precision format to handle large numbers accurately.
- **Key fields**: `transaction_hash` for unique identification, `block_timestamp` for time-based grouping, `gas_used_amount` and `gas_price` for L2 fee calculation, `receipt_l1_fee` for L1 fee component

### Component B: Fee amount calculation
- **Purpose**: Calculate the total transaction fee by combining L1 and L2 components
- **Logic**: For each transaction, calculate the L2 gas fee by multiplying `gas_used_amount` by `gas_price` and dividing by 1e18 to convert from wei to ETH. Calculate the L1 gas fee by dividing `receipt_l1_fee` by 1e18 for decimal correction. Sum the L1 and L2 components using coalesce to handle null values, defaulting to zero if either component is missing. This dual-component approach reflects Optimism's rollup architecture where users pay for both L2 execution and L1 data availability.
- **Key fields**: `l2_gas_fee_amount` as the calculated L2 portion, `l1_gas_fee_amount` as the L1 portion, `fee_amount` as the total combined fee

### Component C: Daily median calculation
- **Purpose**: Aggregate transaction fees by day and calculate the median value
- **Logic**: Group all transactions by day using timestamp truncation to day boundaries. For each day, collect all individual transaction fee amounts and calculate the median using the 50th percentile of the distribution. This is implemented using approximate quantiles calculation that divides the distribution into 100 buckets and selects the middle value.
- **Key fields**: `timestamp` as the daily boundary, `transaction_fee_median` as the calculated median fee amount in ETH

### Final aggregation
- **Combining components**: The daily median values are passed through unchanged from the intermediate calculation, maintaining the day-level aggregation
- **Currency conversion**: Convert median fee amounts from ETH to USD using end-of-day price feeds, joining on the daily timestamp and WETH token address. The conversion maintains decimal precision without additional decimal correction since the fee amounts are already normalized to ETH units.
- **Time aggregation**: Data is aggregated at daily boundaries using timestamp truncation, with each day containing a single median value representing the typical transaction fee for that period
- **Final calculation**: The final metric value represents the median transaction fee in USD for each day, calculated by taking the 50th percentile of all individual transaction fees (both L1 and L2 components combined) for transactions occurring within each 24-hour period, then converting the ETH-denominated result to USD using end-of-day exchange rates

*This methodology was automatically generated by Token Terminal's methodology analyzer.*

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Median transaction fee

Median transaction fee

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