Sign a message
When a web application is connected to Phantom, it can also request that the user signs a given message. Applications are free to write their own messages which will be displayed to users from within Phantom’s signature prompt. Message signatures do not involve network fees and are a convenient way for apps to verify ownership of an address.
In order to send a message for the user to sign, a web application must:
- Provide a hex or UTF-8 encoded string as a Uint8Array.
- Request that the encoded message is signed via the user’s Phantom wallet.
For an example of signing a message, refer to handleSignMessage in our sandbox.
Phantom uses Ed25519 signatures for Solana message signatures. To verify a message signature, you can use the tweetnacl npm package.
signMessage()
request()
Sign-In with Solana (SIWS)
Developers who use signMessage
to authenticate users can now take advantage of Phantom’s new Sign-In with Solana feature. For more information, refer to our specification on GitHub.
Support for other “Sign-In with” Standards
Phantom supports a range of “Sign-In with” (SIW) message standards. You can read more about them in Sign a message.