Developers

GM Wallet SDK

The official SDK to connect a web dApp to the GM Wallet app and request signatures and transactions. Desktop shows a QR code; mobile opens the app directly.

Install

terminal

npm install @mammothlabs/gmwallet-sdk

npm GitHubnpm · source code (MIT)

Quick start — connect

app.ts

import { createWalletSDK } from "@mammothlabs/gmwallet-sdk";

const sdk = createWalletSDK({
  name: "My dApp",                 // shown in the wallet approval sheet
  url: "https://mydapp.com",       // your site origin (used for the verified-site check)
  icons: "https://mydapp.com/icon.png",
  isMainnet: true,                 // true = 체인 ID 8989
});

const res = await sdk.connect({ theme: "dark" });
if (res.success) {
  console.log("connected:", sdk.getState().address);
} else {
  console.error(res.error);
}

Main methods

connect()
Connect the wallet. Waits until the user approves in the app (up to 5 minutes).
personal_sign()
Sign a message, e.g. for sign-in. No funds move.
eth_sendTransaction()
Send GMMT or call a contract. The app decodes the request and asks the user to approve.
eth_signTypedDataV4()
EIP-712 typed-data signature.
getState() · disconnect()
Connection state, address, last tx hash; disconnect.

Sign a message (sign-in)

const { address } = sdk.getState();
const res = await sdk.personal_sign(address!, "Sign in to My dApp\nNonce: 7f21c0a9", "Sign in");
if (res.success) {
  const signature = sdk.getState().signHash; // verify on your server by recovering the address
}

Send a transaction

value is a string in GMMT units: "1" means 1 GMMT, not wei.

// value is a string in GMMT units: "1" = 1 GMMT, "0.5" = 0.5 GMMT (not wei)
const res = await sdk.eth_sendTransaction(address!, "0xRecipient…", "0.5");
if (res.success) console.log("tx:", sdk.getState().tx);

// contract call: value "0" + rawData (ABI-encoded call)
await sdk.eth_sendTransaction(address!, tokenAddress, "0", encodedCallData);

Typed data (EIP-712)

await sdk.eth_signTypedDataV4(address!, {
  domain: { name: "My dApp", version: "1", chainId: "8989", verifyingContract: "0x…" },
  primaryType: "Order",
  types: {
    EIP712Domain: [
      { name: "name", type: "string" },
      { name: "version", type: "string" },
      { name: "chainId", type: "uint256" },
      { name: "verifyingContract", type: "address" },
    ],
    Order: [{ name: "amount", type: "uint256" }],
  },
  message: { amount: "1000000000000000000" },
});

What users see

The connect sheet shows your site name and URL, whether it is a verified site, and what the site can and cannot do.
If you request an unlimited token approval, the app defaults to allowing only the user’s current balance.
Permit-style signatures (EIP-2612) show a red warning. Request them only when you must.
Every call returns { success, data, error } instead of throwing.