---
title: "gm \U0001F44B web3, welcome aboard to Sign in with Web3 (Solana, Ethereum)"
description: Ethereum and Solana wallet authentication now supported in Supabase Auth.
author: stojan
date: '2025-10-03T10:00:00'
tags:
  - select
categories:
  - launch-week
---
Today we're announcing [support for Web3 logins using Ethereum and Solana](https://supabase.com/docs/guides/auth/auth-web3). This has been one of the historically most requested features for Supabase.

It's all based on the widely adopted [Sign in with Ethereum standard (EIP-4361)](https://eips.ethereum.org/EIPS/eip-4361), which both Ethereum and Solana off-chain wallet authentication is based on. This protocol is widely adopted across all of the popular wallet applications (both software and hardware) today, so building a Web3 application on top of Supabase has never been easier.

## How does it work?

We wanted to make it simple. The Sign in with Ethereum standard defines a particular message structure, one that looks like so:

```
example.com wants you to sign in with your Ethereum account:
0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2

I accept the ExampleOrg Terms of Service: <https://example.com/tos>

URI: <https://example.com/login>
Version: 1
Chain ID: 1
Nonce: 32891756
Issued At: 2021-09-30T16:25:24Z
Resources:
- <https://example.com/my-web2-claim.json>
```

It's interpreted both by the wallet application, which presents a secure login confirmation dialog, while also being validated by Supabase Auth before issuing a user session.

Most of these details are already handled for you by the Supabase JavaScript SDK, so it's really as simple as calling this in your Web3 app:

```tsx
await supabase.auth.signInWithWeb3({
  chain: 'ethereum', // or 'solana'
  statement: 'I <3 Supabase!',
})
```

The API is powerful enough to support more modern approaches to building Web3 applications such as using the [Solana Wallet Adapter](https://solana.com/developers/courses/intro-to-solana/interact-with-wallets#solanas-wallet-adapter) system or the [Ethereum Wallet Discovery Mechanism](https://docs.metamask.io/wallet/tutorials/react-dapp-local-state).

You can configure these on the Supabase Dashboard, or in the Supabase CLI:

```toml
[auth.web3.solana]
enabled = true

[auth.web3.ethereum]
enabled = true

```

Don't forget to configure rate-limits and CAPTCHA, as Web3 apps are usually more prone to abuse by bots:

```toml
[auth.rate_limit]
# Number of Web3 logins that can be made in a 5 minute interval per IP address.
web3 = 30

[auth.captcha]
enabled = true
provider = "hcaptcha" # or other supported providers
secret = "0x0000000000000000000000000000000000000000"

```

## How we built it?

At Supabase we cherish our community and our contributors. For this feature, we asked our community for help by co-sponsoring a bounty with the Solana Foundation. We asked them to [help us find a contributor](https://x.com/nickfrosty/status/1880046815950836179) who knows the ecosystem well to help us launch:
![request for contributors](/images/blog/select/2025/login-w-solana-ethereum/twitter-nickfrosty.png)

And we [found](https://x.com/Bewinxed/status/1880148679165976930) someone great!

![Omar (Bewinxed) twitter answer](/images/blog/select/2025/login-w-solana-ethereum/twitter-bewinxed.png)

> Being in the Web3 space, specifically in Solana since 2021, I've used Supabase on a few projects. So as soon as I saw the tweet saying Supabase needed help implementing Sign in with Solana, I had to jump in!
>
> It was interesting seeing the difference when building for Supabase scale, as opposed to building small personal projects. We put in a lot of effort to provide the Web3 community with the great DX Supabase is known for, security and standards compliance.
>
> *— Omar (Bewinxed), Supabase contributor and author of deauth.xyz*

Once we made Sign in with Solana available in April, we decided to further our collaboration and continue working on the Sign in with Ethereum implementation. Omar has continued working with us on other exciting features coming soon!

## Start using Sign in with Web3 today

Real-world use cases for Web3 authentication are already here. Developers are using wallet-based sign-in to power:

- NFT marketplaces where collectors can trade digital assets securely
- DAOs that rely on wallet verification for membership and voting
- Token-gated applications that unlock features based on wallet contents
- DeFi dashboards that let users manage assets without creating yet another password

You can get started right now:

- Check out the [docs for Sign in with Web3](https://supabase.com/docs/guides/auth/auth-web3)
- [Sign up for Supabase](https://www.supabase.com/dashboard) and try it in your project

We can’t wait to see what you build.