Check if address has a deployed contract

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1

Unlike the EVM in StarknetOS all addresses correspond to contracts (not accounts), but I’m not sure what’s the preferred way to check whether a given address corresponds to a deployed smart contract or not?

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2

Hello!
At some point there were discussions abut having something similar to extcodehash on Ethereum. That would fit the bill, right?
I’ll ask around next week if we moved along with that

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3

So I guess there’s no way to do it yet.

I think so, yes.

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4

Full nodes will be able to provide this information, basically the question reduces to the following:

Is the leaf corresponding to a given address in the Merkle-Patricia tree whose root is R (available on L1) nonzero?

This information can be relayed trustlessly if you provide the path proving the leaf’s value.

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5

Will you be able to read this information from inside a smart contract?

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6

In Starknet, you can use the getClassHashAt RPC method or starknet_getClassHashAt via a provider. If the address has a deployed contract, it will return the class hash; if not, it typically returns 0x0 or throws an error. This is the standard way to check for deployed contracts.

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The question was whether smart contracts can check that.

8

-Hello! Have you ever encountered a situation like this? I transferred Starknet coins from an exchange to a wallet. There were no transactions for a year. After the last transfers, all the coins were transferred to a smart contract. I don’t understand where it came from or what to do with it. The support team responded that the system can deploy a smart contract on its own during interactions (in short). According to Starknet, an account is a smart contract. What kind of interaction is this? And how did it happen? There were no transactions with other dApps.

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Hi @Android
This is a great question — and yes, it can definitely be confusing if you’re newer to Starknet.

Let me try to break it down:

On Starknet, accounts are smart contracts.
This means that when you create a wallet, what you’re actually doing is deploying an account contract on-chain. It’s very different from EVM chains like Ethereum, where wallets are just keypairs.

So what likely happened:
When you first funded the address from an exchange, the account contract hadn’t yet been deployed (especially if you were using an “account abstraction” wallet like Argent X or Braavos). Later on, once you interacted with your wallet or approved a transaction, the wallet client auto-deployed the smart contract account using those initial funds (Starknet ETH) to cover gas.

Even if there were no dApp interactions, this account deployment is considered a transaction. You can check this on Starkscan or Voyager by looking at the first transaction from your wallet — it will probably say something like “Deploy Account”.

just incase you’re not sure where your funds went, I’d recommend checking:

  • starkscan.co (search your address)
  • Look for a DEPLOY_ACCOUNT transaction
  • The account it was deployed to should match your wallet address

Let me know if you need help interpreting what you see — happy to help!