Sign messages

Sign messages on Solana and Ethereum using the Phantom Connect Browser SDK’s chain-specific methods.

The Phantom Connect Browser SDK provides chain-specific message signing methods through dedicated interfaces (sdk.solana and sdk.ethereum).

Chain-specific message signing

Solana message signing

// Sign a message with Solana wallet
const { signature, publicKey } = await sdk.solana.signMessage("Hello Solana!");
// Returns: { signature: Uint8Array, publicKey: string }

The Solana signature is a 64-byte Uint8Array. Encode it, for example as base58 with bs58, before you display it or send it to a backend.

Ethereum message signing

// Sign personal message
const signature = await sdk.ethereum.signPersonalMessage("Hello Ethereum!", address);
// Returns: hex-encoded signature string

// Sign EIP-712 typed data
const typedDataSignature = await sdk.ethereum.signTypedData(typedData, address);
// Returns: hex-encoded signature string

Complete examples

The Solana example encodes signatures with bs58. Install it before running the example:

npm install bs58

Solana message signing

import { BrowserSDK, AddressType } from "@phantom/browser-sdk";
import bs58 from "bs58";

const sdk = new BrowserSDK({
  providers: ["injected"],
  addressTypes: [AddressType.solana],
});

await sdk.connect({ provider: "injected" });

// Sign a message; the signature is returned as raw bytes
const { signature, publicKey } = await sdk.solana.signMessage("Hello Solana!");
console.log("Signature (base58):", bs58.encode(signature));
console.log("Signer:", publicKey);

Ethereum message signing

import { BrowserSDK, AddressType } from "@phantom/browser-sdk";

const sdk = new BrowserSDK({
  providers: ["injected"],
  addressTypes: [AddressType.ethereum],
});

await sdk.connect({ provider: "injected" });
const accounts = await sdk.ethereum.getAccounts();

// Sign personal message
const message = "Hello Ethereum!";
const signature = await sdk.ethereum.signPersonalMessage(message, accounts[0]);
console.log("Signature:", signature);

EIP-712 typed data signing

const typedData = {
  types: {
    EIP712Domain: [
      { name: "name", type: "string" },
      { name: "version", type: "string" },
      { name: "chainId", type: "uint256" },
      { name: "verifyingContract", type: "address" }
    ],
    Mail: [
      { name: "from", type: "string" },
      { name: "to", type: "string" },
      { name: "contents", type: "string" }
    ]
  },
  primaryType: "Mail",
  domain: {
    name: "Ether Mail",
    version: "1",
    chainId: 1,
    verifyingContract: "0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC"
  },
  message: {
    from: "Alice",
    to: "Bob",
    contents: "Hello!"
  }
};

const accounts = await sdk.ethereum.getAccounts();
const signature = await sdk.ethereum.signTypedData(typedData, accounts[0]);
console.log("Typed data signature:", signature);