Account impersonation

info

This page is about account impersonation. To read about account class selection and deployment, click here.

Introduction

Devnet allows you to use impersonated account from mainnet/testnet. This means that a transaction sent from an impersonated account will not fail with an invalid signature error. In the general case, a transaction sent with an account that is not in the local state fails with the aforementioned error. For impersonation to work, Devnet needs to be run in forking mode.

Caveat

• Only INVOKE and DECLARE transactions are supported. DEPLOY_ACCOUNT transaction is not supported, but you can create an INVOKE transaction to UDC.
• Overall fee, for transactions sent with an impersonated account, will be lower compared to normal transactions. The reason is that validation part is skipped.
• The most common way of sending a transaction is via starknet-rs/starknet.js or starkli. Trying to send with an account that does not exist even in the origin network will return an error:
  • In transaction construction, if account nonce is not hardcoded, Devnet is queried and returns ContractNotFound.
  • Otherwise the nonce fetching part is skipped and InsufficientAccountBalance is returned.

Disabling impersonation

Users can disable account impersonation by starting Devnet with CLI flag --disable-account-impersonation or by setting environment variable DISABLE_ACCOUNT_IMPERSONATION. Every subsequent JSON-RPC impersonation request will return an error. This feature can be used in CTFs to prevent participants from easily solving the task.

API

Account impersonation follows JSON-RPC method specification. Each method returns an empty response:

devnet_impersonateAccount

Impersonates a specific account address nonexistent in the local state.

{
    "jsonrpc": "2.0",
    "id": "1",
    "method": "devnet_impersonateAccount",
    "params": {
        "account_address": "0x49D36570D4E46F48E99674BD3FCC84644DDD6B96F7C741B1562B82F9E004DC7"
    }
}

devnet_stopImpersonateAccount

Stops the impersonation of an account previously marked for impersonation.

{
    "jsonrpc": "2.0",
    "id": "1",
    "method": "devnet_stopImpersonateAccount",
    "params": {
        "account_address": "0x49D36570D4E46F48E99674BD3FCC84644DDD6B96F7C741B1562B82F9E004DC7"
    }
}

devnet_autoImpersonate

Enables automatic account impersonation. Every account that does not exist in the local state will be impersonated.

{
    "jsonrpc": "2.0",
    "id": "1",
    "method": "devnet_autoImpersonate",
    "params": {}
}

devnet_stopAutoImpersonate

Stops the effect of automatic impersonation.

{
    "jsonrpc": "2.0",
    "id": "1",
    "method": "devnet_stopAutoImpersonate",
    "params": {}
}