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

# Verify a smart contract

> Verify your Stable contract source on Stablescan with forge verify-contract so users can read and interact with it.

Verification uploads your contract's source code to the block explorer and proves it compiles to the deployed bytecode. Once verified, users can read state, call functions, and audit the source on Stablescan without re-hosting your code. This guide walks through verifying a Foundry-deployed contract on Stable.

## Prerequisites

* A contract already deployed on Stable testnet or mainnet. If you haven't deployed yet, see [Deploy a smart contract](/en/tutorial/smart-contract).
* Foundry installed (`forge` available in your PATH).
* The deployed contract address from your `forge create` output.

## 1. Confirm the deployed address

Make sure you have the `Deployed to` address from your earlier deployment. From the [Deploy a smart contract](/en/tutorial/smart-contract) flow, this was the value printed after `forge create`.

```bash theme={"dark"}
cast code 0xDeployedContractAddress --rpc-url https://rpc.testnet.stable.xyz | head -c 20
```

```text theme={"dark"}
0x6080604052600436...
```

A non-empty bytecode confirms the contract is deployed at that address.

## 2. Run forge verify-contract

Foundry's verification flow submits your source to the Stablescan verifier.

```bash theme={"dark"}
forge verify-contract \
  0xDeployedContractAddress \
  src/Counter.sol:Counter \
  --chain-id 2201 \
  --verifier blockscout \
  --verifier-url https://testnet.stablescan.xyz/api \
  --watch
```

```text theme={"dark"}
Start verifying contract `0xDeployedContractAddress` deployed on 2201

Submitting verification of contract: Counter
Submitted contract for verification:
        Response: `OK`
        GUID: `abc123...`
        URL: https://testnet.stablescan.xyz/address/0xDeployedContractAddress
Contract verification status:
Response: `OK`
Details: `Pass - Verified`
Contract successfully verified
```

`--watch` blocks until verification finishes so you don't have to poll. On mainnet, swap the chain ID to `988` and the verifier URL to `https://stablescan.xyz/api`.

<Note>
  **Constructor arguments**: If your contract takes constructor arguments, add `--constructor-args $(cast abi-encode "constructor(uint256,address)" 42 0xSomeAddress)` to the command. Without this flag, verification fails for any contract with a non-empty constructor.
</Note>

## 3. Confirm verification on Stablescan

Open the contract page on the explorer.

```text theme={"dark"}
https://testnet.stablescan.xyz/address/0xDeployedContractAddress
```

The **Contract** tab should now show source code, a green "Verified" badge, and the full ABI. Users can read state under **Read Contract** and send transactions under **Write Contract**.

## Troubleshooting

* **"Bytecode does not match"**: your source compiles to different bytecode than what's deployed. Most often caused by mismatched Solidity version or optimizer settings. Pass `--compiler-version` and `--optimizer-runs` explicitly to match your `foundry.toml`.
* **"GUID not found"**: the verifier hasn't registered your submission yet. Re-run with `--watch` or manually check the URL printed in the response.
* **Contract uses libraries**: add `--libraries src/Lib.sol:Lib:0xDeployedLibAddress` for each linked library.

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