replay_tx
Spin up an anvil-zksync node that forks a remote network and immediately re-executes a chosen L2 transaction.
Perfect for step-through debugging or gas cost inspection of real world transactions and contract interactions.
Synopsis
anvil-zksync replay_tx --fork-url <FORK_URL> <TX>
Both parameters are required:
--fork-url <FORK_URL>- remote endpoint or chain alias<TX>- L2 transaction hash to replay
Named chain aliases
| Alias | RPC endpoint | 
|---|---|
era, mainnet | https://mainnet.era.zksync.io | 
era-testnet, sepolia-testnet | https://sepolia.era.zksync.dev | 
abstract | https://api.mainnet.abs.xyz | 
abstract-testnet | https://api.testnet.abs.xyz | 
sophon | https://rpc.sophon.xyz | 
sophon-testnet | https://rpc.testnet.sophon.xyz | 
cronos | https://mainnet.zkevm.cronos.org | 
cronos-testnet | https://testnet.zkevm.cronos.org | 
lens | https://rpc.lens.xyz | 
lens-testnet | https://rpc.testnet.lens.xyz | 
openzk | https://rpc.openzk.net | 
openzk-testnet | https://openzk-testnet.rpc.caldera.xyz/http | 
zkcandy | https://rpc.zkcandy.io | 
Arguments
| Name | Description | 
|---|---|
<TX> | Transaction hash (0x…, 32 bytes). Required. | 
Options
| Flag | Description | 
|---|---|
--fork-url <FORK_URL> | Network to fork from (endpoint or alias). Required. | 
All global flags (verbosity, cache, gas tuning, etc.) are also available.
Behavior
- Downloads block state up to (but not including) 
<TX>. - Replays the transaction locally, reproducing calldata & timestamp.
 - Provides full VM traces, logs, and storage-diff when 
-vvor higher is enabled. 
Examples
1. Replay a swap transaction from Era mainnet
anvil-zksync replay_tx \
  --fork-url mainnet \
  0xe56fd585309971c7c68b19c6c75a39c4b450731f9884c7b73e13276bb6db9b5b
2. Replay a tx from a local node
anvil-zksync replay_tx \
  --fork-url http://127.0.0.1:3050 \
  0xdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef
3. Replay a failed transaction with user VM tracing
anvil-zksync -vv replay_tx \
  --fork-url mainnet \
  0x9419f4eb8d553dd4f4d254badfd28efb0b2416c4b0eb26076f90e1226501a3e0
See also
fork— fork without replayrun— fresh, empty chain- CLI overview — global flags and usage