ZKsync Chain Calculator

Tools for analyzing operator address runway and funding needs for ZKsync chains.

Works with any ZKsync chain (ZK Stack). Supports both Rollup (EIP-4844 blobs) and Validium (off-chain DA) modes.

Setup

1. Copy the example environment file and fill in your chain's values:

cp .env.example .env

2. Edit .env with your chain's RPC endpoints, operator addresses, and DA mode.

Required fields:

• L1_RPC -- Ethereum mainnet RPC (Alchemy recommended for transfer history queries)
• L2_RPC -- Your L2 chain's RPC endpoint
• COMMIT_OPERATOR, PROVE_OPERATOR, EXECUTE_OPERATOR -- L1 operator addresses
• WATCHDOG_ADDRESS -- Watchdog address (same address used on both L1 and L2)

Optional fields:

• CHAIN_NAME -- Display name (default: "ZKsync Chain")
• DA_MODE -- rollup or validium (default: rollup)
• PUBDATA_PER_TX -- Estimated bytes of pubdata per L2 transaction (default: 300). Run measure_pubdata.py to measure this for your chain (see below).

Scripts

measure_pubdata.py -- Measure PUBDATA_PER_TX

Run this first to determine the right PUBDATA_PER_TX value for your chain. It samples recent L2 blocks, classifies transaction types, and estimates pubdata based on the observed mix.

python3 measure_pubdata.py

The script will:

• Sample 50 recent L2 blocks and classify each transaction (simple transfer, ERC-20, contract call, etc.)
• Derive the current batch size from L1 commit frequency
• Estimate pubdata per tx based on storage slots written per tx type (~60 bytes/slot)
• Determine whether batches are sealing on block count or pubdata limit
• Print a recommended PUBDATA_PER_TX value

Typical ranges by chain activity:

Chain type	PUBDATA_PER_TX
Mostly simple transfers	150-200
Mixed transfers + tokens	200-400
DeFi heavy (swaps, LPs)	400-800
Gaming / NFTs	300-600
Complex contract interactions	800-2000

After running, update your .env:

PUBDATA_PER_TX=200   # or whatever the script recommends

runway_report.py -- Detailed CLI Report

Produces a comprehensive text report covering:

• Current balances for all operator addresses (L1) and watchdog (L1 + L2, tracked separately)
• Historical spending rates over 7-day and 30-day windows
• L1 gas price history (sampled baseFee from block headers)
• Runway estimates at current, historical, and stress-test gas prices
• Funding recommendations for 3, 6, and 12 month horizons
• TPS scaling model showing how L1 costs change at higher throughput
• L2 TPS and chain statistics

cd ZKsync-Chain-Calculator
python3 runway_report.py

funding_calculator.py -- Interactive HTML Calculator

Generates a self-contained HTML file that partners can open in any browser. No server or dependencies needed.

Interactive controls:

• DA Mode toggle -- switch between Rollup and Validium to compare costs
• TPS slider -- see how funding needs change from 0.01 to 300 TPS
• Pubdata/tx input -- adjust the estimated pubdata per transaction

Tables show funding needed (per address) for 3/6/12 months at historical gas prices and stress scenarios (1, 5, 10, 20 gwei).

cd ZKsync-Chain-Calculator
python3 funding_calculator.py
# Opens: <chain_name>_funding.html

DA Modes

Rollup

Pubdata is posted to Ethereum L1 via EIP-4844 blob transactions. Commit transactions carry a blob sidecar.

• L1 costs scale with TPS: more transactions means more pubdata, which triggers smaller batches and more frequent L1 commits.
• Each batch fits in 1 blob (batch pubdata limit of 110KB < blob size of 128KB).
• Cost per commit = execution gas + blob gas.

Validium

Pubdata is stored off-chain (DA committee or external DA layer). Only commitments/hashes are posted to L1.

• No blob gas charged on commit transactions (the main cost saving vs Rollup).
• Batch frequency still scales with TPS: the batch sealing criteria (pubdata limit, tx-per-batch limit) still apply because the VM still generates state diffs regardless of DA mode. Higher TPS still means more batches per day and more L1 operator transactions.
• The saving is the blob gas per commit, which is modest at current blob prices (~4% of commit cost) but can be significant during blob gas spikes.

Requirements

• Python 3.8+
• No external packages needed (uses only stdlib: json, urllib, statistics)
• L1 RPC should support Alchemy's alchemy_getAssetTransfers for operator transaction history and deposit tracking