> ## Documentation Index
> Fetch the complete documentation index at: https://l2docs.whitechain.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Legacy L1 proxy contract verification

> How to verify proxy smart contracts on the legacy Whitechain L1 Explorer, and which hostname to use after the L2 Mainnet launch cut-over.

<Note>
  This page documents the legacy Whitechain Layer 1 (L1), mainnet chain ID `1875`. The L1 is live and producing blocks. It is a separate chain from the Whitechain Layer 2 (L2) documented in the rest of these docs, and it migrates to the L2 at L2 Mainnet launch. To verify a proxy contract on the L2, see [Verify a proxy contract](/build/deploy/verify-proxy-contracts).
</Note>

To verify a proxy contract, use the interface at [https://explorer.whitechain.io/verify-contract/proxy](https://explorer.whitechain.io/verify-contract/proxy).

That hostname serves the legacy L1 explorer (chain ID `1875`) today. At L2 Mainnet launch it begins serving the L2 explorer, and the L1 explorer moves to `https://legacy-explorer.whitechain.io`, where the proxy verification form is at `https://legacy-explorer.whitechain.io/verify-contract/proxy`. From then on, verify an L1 proxy at the legacy hostname; verifying at `explorer.whitechain.io` submits against the L2. See [Endpoint and domain changes](/learn/general/migration#endpoint-and-domain-changes).

<Info>
  Please Note: the implementation contract must be verified first for proxy contract verification.
</Info>

The form has a single field, "Contract Address". Paste the address of the proxy contract into it and submit the form.

<figure><img src="https://lh7-us.googleusercontent.com/HD8BK9dIgE-bRbcDo1cVbkWnU1Ki6uhRsHzLN0z_FE_b2xG0Rl8psh85li9D0z43CVJ-ncOL_ILA-M9Rkpvepw8VrV2gKbV8FnmNazV7HOoFhmG1_6Wwdkgat60N6uhOX30Nxq9ns2fwx-Ed1Dsp4A" alt="The proxy contract verification form on the legacy Whitechain L1 Explorer, showing a single Contract Address input field for the proxy contract address." width="375" /><figcaption>The proxy contract verification form on the legacy Whitechain L1 Explorer.</figcaption></figure>

Once your proxy and implementation contracts are verified, you will see a confirmation pop-up where you must select "Save".

You can verify a proxy contract by providing its code through the [standard flow](/legacy/smart-contracts/verification). Now, after verification, your contract can be read and written as a proxy.