23. ENS, DEX & Identity
Overview
Section titled “Overview”This lesson covers ENS, a first look at DEX mechanics, and onchain identity — three threads that make apps usable by humans rather than by hex addresses. ENS and identity are the focus here; the DEX portion previews the Module 5 capstone.
Key concepts
Section titled “Key concepts”- ENS (Ethereum Name Service) — a naming system that maps human-readable names like
alice.ethto addresses (and more). It’s the DNS of Ethereum: instead of sharing0x71C7…, you sharealice.eth, and apps resolve it to the address. Names are themselves NFTs, owned and managed onchain. - Why names matter — addresses are unreadable and easy to mis-copy; a resolvable name improves UX and reduces “wrong address” mistakes. Many dApps resolve and display ENS names automatically.
- Onchain identity — your address (optionally with an ENS name and associated records) acts as a portable identity across apps. This connects to Sign-In with Ethereum (SIWE): users authenticate to an app by signing a message with their wallet, no password or central account needed — the concrete version of “the wallet replaces login” from Module 1.
- DEX preview — a decentralized exchange lets users swap tokens through a contract rather than an order-book intermediary. This lesson introduces the idea; the Module 5 capstone (and the Token Vendor from Module 3) build toward the mechanics.
- Identity is composable — because these records live onchain, other contracts and apps can read them, so identity isn’t locked inside one platform.
Common pitfalls
Section titled “Common pitfalls”- Thinking an ENS name is the account. It’s a pointer to an address; the address (and its key) is still what controls funds.
- Assuming resolution is automatic everywhere. Apps have to look ENS up; not every context shows names.
- Confusing SIWE (proving control of an address by signing) with a traditional login. There’s no server-side password or account being created.
Check yourself
Section titled “Check yourself”- What problem does ENS solve, and what does a name actually point to?
- How does Sign-In with Ethereum authenticate a user without a password?
- In one sentence, how does a DEX differ from a centralized exchange?
Watch the Video
Section titled “Watch the Video”
ENS, DEX & Identity
Video credit: Austin Griffith