> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dokrypt.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Chain Utilities

> Time-travel, set balances, mine blocks, impersonate accounts, and more.

## 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:

```bash theme={null}
# 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:

```bash theme={null}
# 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

```bash theme={null}
# 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
```

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

## Setting Balances

Set any account's ETH balance:

```bash theme={null}
dokrypt chain set-balance 0x70997970C51812dc3A010C7d01b50e0d17dc79C8 500
```

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

```bash theme={null}
dokrypt chain set-balance 0x1234...abcd 0.5
```

## Impersonating Accounts

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

```bash theme={null}
# 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

```bash theme={null}
# 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:

```bash theme={null}
# Set gas price to 50 gwei
dokrypt chain set-gas-price 50
```

## Resetting the Chain

Reset to genesis state or a new fork:

```bash theme={null}
# 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:

```bash theme={null}
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:

```bash theme={null}
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`                     |