If you have used the Base App or a Farcaster client like Warpcast, you have already interacted with Farcaster, even if nobody called it that. It is the protocol underneath a growing set of social apps and Mini Apps that run on or alongside Base. Most people never think about how it works, which is fine for everyday posting, but once you are connecting a wallet to these apps it is worth understanding what is actually onchain and what is not.
A protocol, not a single app
Farcaster is not one app you log into. It is an open protocol, meaning the rules for identities, posts, and following relationships are public and anyone can build a client on top of them. Warpcast and the Base App are two separate clients built on the same underlying network, similar to how multiple email apps can all read the same inbox because they speak the same protocol. That is also why a post, called a cast, shows up the same way whether you view it in one client or another.
Two layers: identity onchain, content off it
Farcaster splits its work across two different places, and the split matters for understanding what a wallet connection actually touches.
Account identity lives onchain, on the Optimism network, through a small set of smart contracts:
- The ID Registry assigns every account a Farcaster ID, a number tied to a custody address, and handles transferring or recovering that ID.
- The Key Registry tracks which signer keys are currently authorized to publish casts on behalf of an account.
- The Storage Registry tracks how much storage space an account has rented for its data.
Casts and everyday activity do not live onchain. They are stored and synced by a separate network layer, now called Snapchain, which replaced Farcaster's earlier hub system in 2025. Snapchain is built for the volume of normal social activity, posting, liking, following, at a speed and cost that would not make sense to put directly on a blockchain. Client apps read from and write to this layer constantly; you are not paying gas every time you post.
Your custody address is your wallet
The custody address tied to your Farcaster ID is a normal wallet address, the same kind you already use to hold tokens on Base. This is the root of your Farcaster account: whoever controls that address can, through the ID Registry contract, transfer or recover the Farcaster ID itself.
That means the habits you already apply to protecting a self-custody wallet apply directly here. If the private key or recovery phrase behind that custody address is lost or compromised, your Farcaster identity is at risk along with everything else that wallet holds. Nothing about Farcaster changes the rule that your recovery phrase should never be typed into a website, a support chat, or a Mini App. For a refresher on why, see our guide on keeping your recovery phrase safe.
Signer keys are a different, smaller permission
Day to day, your client app does not ask your custody wallet to sign every single cast. Instead, Farcaster uses a separate concept called a signer key, an app-specific key that is authorized through the Key Registry to post on your behalf without needing your main wallet's approval for every action.
This is a narrower permission than full wallet access. A compromised signer key could let someone post or interact as you, which is disruptive, but it does not by itself give access to the funds in your wallet the way a leaked recovery phrase would. Knowing this distinction helps you reason correctly about what is actually at risk if a client app or session gets compromised, versus what is at risk if your wallet itself is.
How this connects to Base
Base and Farcaster are built by overlapping teams and share a lot of infrastructure and audience, which is why the Base App doubles as a Farcaster client and why so many Mini Apps embedded in social feeds settle their onchain actions on Base. The identity layer described above sits on Optimism, a separate network, but the apps and transactions you interact with through that identity often run on Base because it is cheap and fast enough for frequent, small onchain actions. We cover how those embedded apps work, and what to check before connecting a wallet to one, in our guide on Farcaster Mini Apps.
What to check before you connect a wallet
A few practical takeaways follow directly from how the protocol is structured:
- Treat your custody wallet like any other wallet holding value. It controls your Farcaster identity through onchain contracts, so the same backup and phishing precautions apply.
- A wallet connection prompt is still a wallet connection prompt. Whether it comes from a Farcaster client, a Mini App, or a standalone site, read what you are approving before you sign. Our guide on connecting your wallet to a dapp safely covers the habits that carry over here.
- A compromised app session is not automatically a compromised wallet, but do not assume the reverse either. If something asks for your seed phrase to "resync" your identity or "verify" your account, that is not how the ID Registry or any legitimate client works.
- If you end up holding a token on Base through activity in a social app or Mini App, swapping or moving it is a separate, ordinary action, distinct from anything related to your Farcaster identity itself.
The bottom line
Farcaster keeps identity ownership onchain, through a small set of contracts on Optimism, while handling the high volume of everyday posting off chain through Snapchain. The practical result for a self-custody wallet user is simple: your custody address is a real wallet with real control over your identity, your signer keys are a narrower and lower-stakes permission, and every wallet confirmation you see in a Farcaster client or Mini App deserves the same attention you would give it anywhere else.