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Signing
Connect the provider before signing and confirm the selected network. The direct injected provider and the Aptos Wallet Standard adapter have different argument types; do not interchange their examples. Replace abbreviated addresses and provide an SDK client for read-only calls.
Learn how to sign messages for authentication or verification.
Sign Message
Sign arbitrary messages for authentication or verification:
const message = 'Welcome to MyApp!\n\nClick to sign in.\n\nNonce: abc123'
const response = await provider.signMessage({
message,
nonce: 12345, // Example only; obtain a single-use challenge from your server
})
console.log({
signature: response.signature, // Hex-encoded signature
fullMessage: response.fullMessage, // Full signed message
prefix: response.prefix, // Message prefix used
})Sign Message Options
const response = await provider.signMessage({
message: 'Hello Aptos',
nonce: 12345,
address: true, // Include address in message
application: true, // Include app info
chainId: true, // Include chain ID
})Verify Message (Off-chain)
import nacl from 'tweetnacl'
const { signature, fullMessage } = await provider.signMessage({
message: 'Hello Aptos',
nonce: 12345,
})
const account = await provider.account()
const pubKeyBytes = Buffer.from(account.publicKey.slice(2), 'hex')
const signatureBytes = Buffer.from(signature.slice(2), 'hex')
const messageBytes = Buffer.from(fullMessage)
const isValid = nacl.sign.detached.verify(messageBytes, signatureBytes, pubKeyBytes)
console.log('Signature valid:', isValid)Sign In (AIP Standard)
For standardized sign-in flow:
const signInInput = {
// Sign-in parameters
}
const result = await provider.signIn(signInInput)
console.log({
address: result.account.address,
publicKey: result.account.publicKey,
signature: result.signature,
})Error Handling
try {
await provider.signMessage({ message: 'Hello', nonce: 12345 })
} catch (error) {
switch (error.code) {
case 4001:
console.log('User rejected the request')
break
case 4100:
console.log('The account or method is not authorized')
break
case 4200:
console.log('Unsupported method')
break
default:
console.error('Error:', error.message)
}
}The direct signMessage method uses a numeric nonce. signMessageCompatible and Wallet Standard integrations use a string nonce. Verify the returned fullMessage, signer, and challenge, and invalidate the challenge after use. The sign-in input above is a schematic placeholder; construct the full AptosSignInInput required by your adapter version.