## Custom methods

Anvil exposes custom RPC methods beyond the standard Ethereum JSON-RPC API. These methods are useful for testing scenarios that require account impersonation, time manipulation, or mining control.

### Account impersonation

Impersonate any account to send transactions without its private key:

```bash [Impersonate an account]
$ cast rpc anvil_impersonateAccount $ADDRESS
```

```bash [Send transaction as impersonated account]
$ cast send $CONTRACT "transfer(address,uint256)" $TO $AMOUNT --from $ADDRESS --unlocked
```

```bash [Stop impersonating]
$ cast rpc anvil_stopImpersonatingAccount $ADDRESS
```

Start Anvil with auto-impersonation enabled:

```bash [Enable auto-impersonation]
$ anvil --auto-impersonate
```

### Mining control

For mining modes, transaction ordering, pool inspection, and deterministic automation patterns, see [Mining and transaction pool](/anvil/mining).

Control when blocks are mined:

```bash [Disable automatic mining]
$ anvil --no-mining
```

```bash [Mine a single block]
$ cast rpc anvil_mine
```

```bash [Mine multiple blocks]
$ cast rpc anvil_mine 10
```

```bash [Set block interval (seconds)]
$ anvil --block-time 12
```

```bash [Enable interval mining via RPC]
$ cast rpc evm_setIntervalMining 12
```

```bash [Resume automatic mining]
$ cast rpc evm_setAutomine true
```

### Time manipulation

Control the blockchain's perception of time:

```bash [Increase time by seconds]
$ cast rpc evm_increaseTime 3600
```

```bash [Set next block timestamp]
$ cast rpc evm_setNextBlockTimestamp 1700000000
```

```bash [Mine block with new timestamp]
$ cast rpc evm_mine
```

### State snapshots

Create and restore chain state snapshots during a session:

```bash [Create snapshot]
$ cast rpc evm_snapshot
```

```bash [Revert to snapshot]
$ cast rpc evm_revert $SNAPSHOT_ID
```

Snapshots return an ID that you use to revert. Reverting removes the snapshot.

### Balance and code manipulation

Modify account state directly:

```bash [Set account balance]
$ cast rpc anvil_setBalance $ADDRESS 0xDE0B6B3A7640000
```

```bash [Set account nonce]
$ cast rpc anvil_setNonce $ADDRESS 0x10
```

```bash [Set contract code]
$ cast rpc anvil_setCode $ADDRESS $BYTECODE
```

```bash [Set storage slot]
$ cast rpc anvil_setStorageAt $ADDRESS $SLOT $VALUE
```

### Chain configuration

Modify chain parameters at runtime:

```bash [Set chain ID]
$ cast rpc anvil_setChainId 31337
```

```bash [Set block gas limit]
$ cast rpc evm_setBlockGasLimit 0x1C9C380
```

```bash [Set next block base fee]
$ cast rpc anvil_setNextBlockBaseFeePerGas 0x5F5E100
```

### Transaction pool

Inspect and manage pending transactions:

```bash [Get pending transactions]
$ cast rpc txpool_content
```

```bash [Drop a transaction]
$ cast rpc anvil_dropTransaction $TX_HASH
```

```bash [Drop all pending transactions]
$ cast rpc anvil_dropAllTransactions
```

### Tracing

Enable execution traces for debugging:

```bash [Enable trace printing]
$ anvil --print-traces
```

```bash [Enable step tracing for debug_* methods]
$ anvil --steps-tracing
```