api/v2/smart-contracts/<ADDRESS>/verification/via/vyper-standard-input is returning 404 Client Error: Not Found for url

[s3bc40]

Hi 👋

I am finally posting in here since I am out of option to solve these following issues on Moccasin (Vyper framework), and Titanoboa (Vyper interpreter):

Cyfrin/moccasin#253
vyperlang/titanoboa#403

Context

We had some feedback from students learning the Vyper course on Cyfrin, that they could not verify their contract on Sepolia testnet. So I tested, and I am also struggling to achieve a verification with Moccasin and Titanoboa:

E           requests.exceptions.HTTPError: 404 Client Error: Not Found for url: https://eth-sepolia.blockscout.com/api/v2/smart-contracts/0xd22070aD3D5d8173498CAc32b7D41cf3d591bAc8/verification/via/vyper-standard-input?apikey=<MY_API_KEY>

.venv/lib/python3.12/site-packages/requests/models.py:1026: HTTPError

To give some Python context, the verification step is like this in Titanoboa:

    if license_type is None:
            license_type = "none"

        api_key = self.api_key or ""

        url = f"{self.uri}/api/v2/smart-contracts/{address}/"
        url += f"verification/via/vyper-standard-input?apikey={api_key}"
        data = {
            "compiler_version": solc_json["compiler_version"],
            "license_type": license_type,
        }
        files = {
            "files[0]": (
                contract_name,
                json.dumps(solc_json).encode("utf-8"),
                "application/json",
            )
        }

        response = requests.post(url, data=data, files=files)
        response.raise_for_status()

We are using the vyper-standard-input API endpoint.

Investigation

Going further in the processing before sending the request, we end up with this multipart/form-data request body:

--8f4a1cc47ad485dbad8aa83fcd31ee41
Content-Disposition: form-data; name="compiler_version"

v0.4.3+commit.bff19ea2
--8f4a1cc47ad485dbad8aa83fcd31ee41
Content-Disposition: form-data; name="license_type"

1
--8f4a1cc47ad485dbad8aa83fcd31ee41
Content-Disposition: form-data; name="files[0]"; filename="ipuwbnvcso"
Content-Type: application/json

{
  "language": "Vyper",
  "sources": {
    "tests/integration/network/sepolia/module_lib.vy": {
      "content": "# pragma version ~=0.4.0\n\n@view\ndef throw():\n    raise \"Error with message\"\n\ndef throw_dev_reason():\n    raise # dev: some dev reason\n",
      "sha256sum": "a50c95427d9e79507ed1179f137a5d6cbe2b22c156d88281d4d6109f10cd40ec"
    },
    "<unknown>": {
      "content": "\nimport module_lib\n\n@deploy\ndef __init__(t: uint256):\n    if t == 0:\n        module_lib.throw()\n\n@external\ndef ipuwbnvcso() -> uint256:\n    return 5591906717906843636306105947619866331449843430409101901995410518206380090736\n",
      "sha256sum": "c931e5a511e6544974baa20460b5949e1aac534c949b631ad19c1b9b6dd28da9"
    }
  },
  "settings": {
    "outputSelection": {
      "<unknown>": [
        "*"
      ]
    },
    "search_paths": [
      ".",
      "tests/integration/network/sepolia"
    ]
  },
  "compiler_version": "v0.4.3+commit.bff19ea2",
  "integrity": "0100ae8f2064b45c9d61e03aaf18e195e0dcc83e0625e68c03233acea02ecca1"
}
--8f4a1cc47ad485dbad8aa83fcd31ee41--

I have checked the output directly on my browser too (https://eth-sepolia.blockscout.com/api/v2/smart-contracts/0xd22070aD3D5d8173498CAc32b7D41cf3d591bAc8):

{
  "creation_bytecode": "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",
  "creation_status": "success",
  "deployed_bytecode": "0x5f3560e01c630aee8499811861003e5734610042577f38fa08cb8c72b174ff5b07a8017f1114a1ee7085ab9b46112c21b2130b82696f60405260206040f35b5f5ffd5b5f80fd",
  "implementations": [],
  "is_self_destructed": false,
  "proxy_type": "unknown"
}

And on the Scalar API Client accessible from the BlockScout doc, I saw in the response that we get Address is not a smart-contract and I tried to understand where it was coming from:
async fn fetch_and_apply_address_endpoint_response

I also checked the API endpoints there smart-contract-verifier.swagger.yaml, but I think I am getting lost, and the right endpoints are in the blockscout-smart-contract-verification-api doc.

---

Any chance to get some insights on this? I am trying to contribute as much as I can to help the Vyper community and I have to admit that alone I might not reach a good solution. Maybe we have to update something.

Sorry if it is not clear or not posted in the right tab, but I am available if you need any details.

Thanks for your help!

[PatrickAlphaC]

bump

[GimluCom]

        url += f"verification/via/vyper-standard-input?apikey={api_key}"

An API key is not required to verify a contract on Blockscout.

I have checked the output directly on my browser too (https://eth-sepolia.blockscout.com/api/v2/smart-contracts/0xd22070aD3D5d8173498CAc32b7D41cf3d591bAc8)

Your contract is actually located on this address: 0x510dEF6899250a044B166039a602C6d9fDfa9689

[s3bc40]

Thanks for the reply!

Since it for testing purposes, I am trying to deploy and verify the same contract other and other again to pass the tests. On Eherscan, even though I am deploying + verifying the contract, it passes with the right address.

Does Blockscout have the same behavior? Maybe I need to adapt how we call the API since in the code it doesn't seem to pass the chainid by default while verifying 🤔

Seems like 0x510dEF6899250a044B166039a602C6d9fDfa9689 is the original one. I'll further investigate. Or just the previous contract deployed and verified on Etherscan following the test order.

[s3bc40]

I fixed my issue. Apparently, I need to ensure that my deployed contract is recognized as a contract or already verified with the following API:

api_contract_url = f"{self.uri}/api/v2/addresses/{address}"

By waiting in a session to get is_contract=true or is_verified=true, the previous call to verify with Vyper is working 👍

I managed to get this by testing on the Blockscout explorer and checking the Fetch/xhr tab of Networks.