Network Fee Estimation

zerohash provides an estimated network fee endpoint that returns approximate withdrawal costs based on current blockchain conditions. Fee estimates are available in both PROD and CERT environments.

⚠️ Test networks (CERT) can behave very differently from mainnet (PROD). Estimated fees and volatility often vary significantly because test tokens lack real monetary value, removing economic incentives for miners and validators to prioritize high fee transactions.

How Estimates Work by Blockchain

UTXO Chains (i.e. Bitcoin, Litecoin, Bitcoin Cash)

Network fee estimates for BTC are sourced from transactions on either the main or testnet mempool, depending on which environment is being used.

Method: Analyzes highest fee-per-byte transactions that would fill a 1MB block, returns the average

Optimization: Targets inclusion in the next 1-2 blocks

Variables: Transaction inputs/outputs, network demand

High network congestion increases returned fee estimates proportionally.

Ethereum / ERC20 Tokens

Since the London hard fork (EIP-1559) and merge to Proof of Stake, Ethereum has standardized 12-second block times and more predictable fees through variable block sizes. However, fees still depend on:

• Network demand
• Computational complexity
• Storage requirements
• Destination address type (smart contracts require higher fees than standard addresses)

Method: Analyzes recent trailing blocks and applies a percentile calculation to optimize for price vs. inclusion speed.

Solana

Solana's high throughput results in consistently low fees with minimal volatility.

Method: Queries Solana's native RPC endpoint for current fee rates.

Other Supported Assets

Assets not specifically listed (Polygon, Avalanche, Arbitrum, etc.) follow the Ethereum model: recent block analysis with percentile optimization for price-speed balance.

Assets without Estimates

A small number of supported assets (e.g., EGLD) do not yet return fee estimates. Integration for these assets is in progress.