Skip to main content
Before you run the quickstart, it helps to understand how passkeys and Circle Smart Accounts work together.

​
Passkey

A passkey is the signer for a modular wallet. The user registers or logs in with a passkey (for example, biometrics, or device unlock); the key material stays on their device and your app never holds it. There is no seed phrase or password for the user to manage. For more on passkeys, backup, and recovery, see Passkeys.

​
Smart account and flow

The passkey is the owner of a Circle Smart Account. In the quickstart, you use the modular wallets SDK to create the smart account with that passkey as owner, then create a bundler client to send user operations. To sponsor gas so the user does not need native tokens, set paymaster: true when sending the user operation (Circle Gas Station covers the fee). For more capabilities (batch, parallel execution, signing), see Modular Wallet Operations.