Chain Utilities

Overview

Chain utilities give you full control over your local blockchain’s state and behavior. These are essential for testing time-dependent logic, simulating edge cases, and debugging transactions.

Mining Blocks

Force mine one or more blocks:

# Mine 1 block
dokrypt chain mine

# Mine 100 blocks
dokrypt chain mine 100

Mining is useful for:

Advancing the chain after sending transactions
Simulating block production in manual mining mode
Testing block-dependent logic

Time Travel

Advance the blockchain’s clock without waiting:

# Advance 1 hour
dokrypt chain time-travel 1h

# Advance 7 days
dokrypt chain time-travel 7d

# Advance 30 minutes
dokrypt chain time-travel 30m

# Advance 3600 seconds (raw number)
dokrypt chain time-travel 3600

After advancing time, Dokrypt automatically mines a block to apply the timestamp change.

Common Use Cases

# Test a vesting cliff (6 months)
dokrypt chain time-travel 180d

# Test a timelock delay (24 hours)
dokrypt chain time-travel 24h

# Test epoch transitions (1 week)
dokrypt chain time-travel 7d

Combine time-travel with snapshots for efficient testing: snapshot before time-travel, test, then restore.

Setting Balances

Set any account’s ETH balance:

dokrypt chain set-balance 0x70997970C51812dc3A010C7d01b50e0d17dc79C8 500

The amount is in ETH (not wei). Supports decimals:

dokrypt chain set-balance 0x1234...abcd 0.5

Impersonating Accounts

Impersonate any address — transactions from this address will succeed without the private key:

# Start impersonating
dokrypt chain impersonate 0xdead...beef

# Stop impersonating
dokrypt chain stop-impersonating 0xdead...beef

This is critical for:

Testing admin-only functions on forked contracts
Simulating whale behavior
Interacting with governance contracts as specific voters

Example: Transfer tokens from a whale

# Fork mainnet
dokrypt fork mainnet

# Impersonate a USDC whale
dokrypt chain impersonate 0x47ac0Fb4F2D84898e4D9E7b4DaB3C24507a6D503

# Now you can call transfer() from this address

Setting Gas Price

Control the base gas price for testing gas-sensitive logic:

# Set gas price to 50 gwei
dokrypt chain set-gas-price 50

Resetting the Chain

Reset to genesis state or a new fork:

# Reset to genesis
dokrypt chain reset

# Reset to a mainnet fork at a specific block
dokrypt chain reset --fork https://eth.llamarpc.com --block 18000000

Chain Information

Display current chain state:

dokrypt chain info

Output:

Chain: ethereum
  Chain ID:    31337
  RPC URL:     http://localhost:8545
  Block:       42
  Timestamp:   1705312200

Multi-Chain Usage

For projects with multiple chains, use --chain to target a specific one:

dokrypt chain mine 10 --chain polygon
dokrypt chain time-travel 1d --chain arbitrum
dokrypt chain set-balance 0x1234... 100 --chain base
dokrypt chain info --chain l2

RPC Methods Used

Under the hood, Dokrypt uses these JSON-RPC methods:

Command	Anvil Method	Hardhat Fallback
`mine`	`anvil_mine`	`evm_mine` (loop)
`set-balance`	`anvil_setBalance`	`hardhat_setBalance`
`time-travel`	`evm_increaseTime`	`evm_increaseTime`
`set-gas-price`	`anvil_setMinGasPrice`	`hardhat_setNextBlockBaseFeePerGas`
`impersonate`	`anvil_impersonateAccount`	`hardhat_impersonateAccount`
`stop-impersonating`	`anvil_stopImpersonatingAccount`	`hardhat_stopImpersonatingAccount`
`reset`	`anvil_reset`	`hardhat_reset`

Getting Started

Core Concepts

Features

Advanced

Chain Utilities

Overview

Mining Blocks

Time Travel

Common Use Cases

Setting Balances

Impersonating Accounts

Example: Transfer tokens from a whale

Setting Gas Price

Resetting the Chain

Chain Information

Multi-Chain Usage

RPC Methods Used

​Overview

​Mining Blocks

​Time Travel

​Common Use Cases

​Setting Balances

​Impersonating Accounts

​Example: Transfer tokens from a whale

​Setting Gas Price

​Resetting the Chain

​Chain Information

​Multi-Chain Usage

​RPC Methods Used

Overview

Mining Blocks

Time Travel

Common Use Cases

Setting Balances

Impersonating Accounts

Example: Transfer tokens from a whale

Setting Gas Price

Resetting the Chain

Chain Information

Multi-Chain Usage

RPC Methods Used