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

# Passkey

> Use device biometrics as the owner of a smart account. Supports single key or n/m multisig.

The Passkey signer uses the WebAuthn Validator module to authorise transactions with device-native biometrics: Face ID, Touch ID, Windows Hello. No seed phrases, no browser extensions. Keys are generated and stored in the device secure enclave and can sync across devices via iCloud Keychain or Google Password Manager.

Passkeys are supported across iOS, Android, macOS, and modern browsers (Chrome, Safari, Edge).

## Single owner

```ts theme={null}
import { RhinestoneSDK } from '@rhinestone/sdk'
import { toWebAuthnAccount } from 'viem/account-abstraction'

const passkeyAccount = toWebAuthnAccount({ credential })

const rhinestone = new RhinestoneSDK({
  apiKey: process.env.RHINESTONE_API_KEY as string,
})

const account = await rhinestone.createAccount({
  owners: {
    type: 'passkey',
    accounts: [passkeyAccount],
  },
})
```

## Multisig

The WebAuthn Validator supports n/m multisig with multiple passkey owners and a configurable signature threshold.

A common use case: users register a passkey per device. You set up a 1-of-n account so the user can sign from any of their devices without needing to migrate keys.

### Setup

```ts theme={null}
const account = await rhinestone.createAccount({
  owners: {
    type: 'passkey',
    accounts: [passkeyAccountA, passkeyAccountB],
    threshold: 2, // 2-of-2: both devices must sign
  },
})
```

By default, `threshold` is `1`, meaning any single passkey can sign.

### Signing with a subset of owners

For m-of-n setups, specify which passkeys to use when sending a transaction:

```ts theme={null}
const result = await account.sendTransaction({
  chain,
  calls: [
    // …
  ],
  signers: {
    type: 'owner',
    kind: 'passkey',
    accounts: [passkeyAccountA],
  },
})
```

<Note>Provide at least as many signers as the threshold requires, or the transaction will fail validation.</Note>

### Add a passkey (new device)

```ts theme={null}
import { addOwner } from '@rhinestone/sdk/actions/passkeys'
import { slice } from 'viem'

const pubKeyX = BigInt(slice(newPasskeyAccount.publicKey, 0, 32))
const pubKeyY = BigInt(slice(newPasskeyAccount.publicKey, 32))
const requiresUV = false

await account.sendTransaction({
  chain,
  calls: [addOwner(pubKeyX, pubKeyY, requiresUV)],
})
```

### Remove a passkey

```ts theme={null}
import { removeOwner } from '@rhinestone/sdk/actions/passkeys'

await account.sendTransaction({
  chain,
  calls: [removeOwner(pubKeyX, pubKeyY)],
})
```

### Change threshold

```ts theme={null}
import { changeThreshold } from '@rhinestone/sdk/actions/passkeys'

await account.sendTransaction({
  chain,
  calls: [changeThreshold(2)],
})
```

### Get current owners

```ts theme={null}
const owners = await account.getOwners(chain)
// → { accounts: ['0xaaa…', '0xbbb…'], threshold: 1 }
```

## Enable in a separate transaction

If you need to enable the passkey module on an existing account rather than at creation time:

```ts theme={null}
import { enable as enablePasskeys } from '@rhinestone/sdk/actions/passkeys'

await account.sendTransaction({
  chain,
  calls: [enablePasskeys(passkeyAccount.publicKey, passkeyAccount.id)],
  tokenRequests: [],
})
```