# Katana Vault Bridge Fees Methodology

## 1. Overview

Fees for Katana Vault Bridge are measured by tracking the yield collected from the vault bridge contracts. Yield is harvested from vault bridge contracts on Ethereum, representing the economic value generated by the bridge. These collected yield amounts are treated as fees generated by the assets within the bridge.

## 2. Data sources

- **Blockchain events**: `YieldCollected` events from `vbUSDC`, `vbUSDT`, `vbETH`, `vbWBTC`, and `vbUSDS` contracts, covering Ethereum
- **External data**: End-of-day price feeds and asset metadata

## 3. Step-by-step calculation

### Component A: Vault bridge yield extraction

- **Purpose**: Raw yield amounts harvested from the vault bridge contracts are captured.
- **Logic**: `YieldCollected` events are parsed from `vbUSDC`, `vbUSDT`, `vbETH`, `vbWBTC`, and `vbUSDS` contracts on Ethereum. The raw yield amount is extracted from the `vbTokenAmount` field for each harvest event. Each event is mapped to its corresponding underlying asset, including USDC, USDT, WETH, WBTC, and USDS.
- **Key fields**: `vbTokenAmount` (representing the harvested yield amount), `address` (representing the vault address), `block_timestamp` (for timing)

### Component B: Decimal normalization

- **Purpose**: Raw yield amounts are normalized to their standard decimal precision.
- **Logic**: Raw yield amounts are divided by the decimal precision of their respective underlying assets. This normalization is performed by joining the event data with asset metadata containing decimal values for each asset.
- **Key fields**: `decimals` (from asset metadata), `yield_amount` (normalized yield)

### Component C: USD conversion and aggregation

- **Purpose**: Normalized yield fees are converted to USD and aggregated daily.
- **Logic**: Normalized daily yield amounts are multiplied by the end-of-day USD prices of the respective underlying assets on Ethereum. The resulting USD values are aggregated to a daily grain. The final fees are mapped to the Katana Chain (`katananetwork`) destination chain and the Katana Vault Bridge product ID.
- **Key fields**: `price_usd` (from end-of-day price feeds), `fees` (final USD value)

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

Total value users pay to use a protocol (gross fees, user-paid fees).

Fees

Bridges

The network uses pessimistic proofs via the AgglayerGateway for settlement on Ethereum, with vault bridges for cross-chain asset transfers.

Katana Network provides a scalable execution environment connected to Ethereum through the Agglayer interoperability layer.

Katana Vault Bridge

Fees

Fees

Chain breakdown