@crossmint/wallets-sdk

Typescript SDK for creating and managing Crossmint Wallets on EVM, Solana, and Stellar chains.

Prerequisites

Get a Crossmint API key from the developer console. Ensure your key has the Wallet API scopes enabled.

Client-side (browser): Use a client API key
Server-side (Node.js): Use a server API key

Installation

npm install @crossmint/wallets-sdk
# or
pnpm add @crossmint/wallets-sdk
# or
yarn add @crossmint/wallets-sdk

Quick Start

Server-side (Node.js)

import { createCrossmint, CrossmintWallets } from "@crossmint/wallets-sdk";

const crossmint = createCrossmint({ apiKey: "<YOUR_SERVER_API_KEY>" });
const wallets = CrossmintWallets.from(crossmint);

// Create a wallet with a server signer
const wallet = await wallets.createWallet({
  chain: "base-sepolia",
  recovery: { type: "server", secret: "<RECOVERY_SECRET>" },
});

console.log(wallet.address);

// Send tokens
const tx = await wallet.send("0xRecipientAddress", "usdc", "10");
console.log(tx.explorerLink);

Client-side (Headless)

For client-side usage without React, you can use the SDK directly with JWT authentication:

import { createCrossmint, CrossmintWallets } from "@crossmint/wallets-sdk";

const crossmint = createCrossmint({ apiKey: "<YOUR_CLIENT_API_KEY>" });
crossmint.setJwt("<USER_JWT>");

const wallets = CrossmintWallets.from(crossmint);

const wallet = await wallets.getWallet({ chain: "base-sepolia" });
console.log(wallet.address);

For React apps, use @crossmint/client-sdk-react-ui which provides CrossmintWalletProvider, hooks, and built-in UI for OTP and passkey flows.

Core Concepts

Signers

Wallets SDK uses a two-tier signer model:

Recovery signer — High-security, used for wallet recovery and adding new signers. Supports email OTP, phone OTP, external wallet, or server key.
Operational signer — Low-friction, used for day-to-day signing. The default is the device signer, which uses hardware-backed keys (no OTP needed). Also supports passkey, server key, and external wallet.

When no operational signer is available, the recovery signer automatically serves as a fallback for signing.

Wallet Lifecycle

// Create a new wallet
const wallet = await wallets.createWallet({
  chain: "base-sepolia",
  recovery: { type: "email", email: "user@example.com" },
  signers: [{ type: "device" }], // optional — device is the default
});

// Retrieve an existing wallet (client-side)
const wallet = await wallets.getWallet({ chain: "base-sepolia" });

// Retrieve an existing wallet (server-side)
const wallet = await wallets.getWallet("0xWalletAddress", {
  chain: "base-sepolia",
});

Usage

Balances

const balances = await wallet.balances();

console.log(balances.nativeToken.amount);
console.log(balances.usdc.amount);

Send Tokens

const tx = await wallet.send("0xRecipient", "usdc", "100");
console.log(tx.explorerLink);

Transfers

const transfers = await wallet.transfers({
  tokens: "usdc",
  status: "successful",
});

NFTs

const nfts = await wallet.nfts({ perPage: 10, page: 1 });

Chain-Specific Transactions

import { EVMWallet, SolanaWallet, StellarWallet } from "@crossmint/wallets-sdk";

// EVM — smart contract interaction
const evmWallet = EVMWallet.from(wallet);
const tx = await evmWallet.sendTransaction({
  to: "0xContractAddress",
  abi: contractAbi,
  functionName: "mint",
  args: [1],
  value: 0n,
});

// EVM — sign a message
const sig = await evmWallet.signMessage({ message: "Hello" });

// EVM — viem public client
const client = evmWallet.getViemClient();

// Solana
const solWallet = SolanaWallet.from(wallet);
const solTx = await solWallet.sendTransaction({
  serializedTransaction: "<base64-encoded-transaction>",
});

// Stellar
const stellarWallet = StellarWallet.from(wallet);
const stellarTx = await stellarWallet.sendTransaction({
  contractId: "C...",
  method: "transfer",
  args: { to: "G...", amount: "1000000" },
});

Signer Management

// Add a new signer
await wallet.addSigner({ type: "server", secret: "<SECRET>" });

// List signers
const signers = await wallet.signers();
console.log(signers); // [{ type: "device", locator: "device:...", status: "success" }, ...]

// Set the active signer
await wallet.useSigner({ type: "server", secret: "<SECRET>" });

// Recovery flow (new device)
if (wallet.needsRecovery()) {
  await wallet.recover(); // uses recovery signer to register a new device signer
}

Transaction Approval (Prepare-Only Mode)

For flows that require multi-step approval:

// Create a transaction without auto-approving
const pendingTx = await wallet.send("0xRecipient", "usdc", "10", {
  prepareOnly: true,
});
console.log(pendingTx.transactionId);

// Approve later
const result = await wallet.approve({
  transactionId: pendingTx.transactionId,
});

Signer Types

Type	Use Case	Platforms
`device`	Default day-to-day signer. Hardware-backed, no OTP.	Browser, React Native
`server`	Server-side automated operations (AI agents, backends).	Node.js
`email`	OTP-based recovery signer.	All
`phone`	OTP-based recovery signer.	All
`passkey`	WebAuthn/FIDO2 biometric signer.	Browser (EVM only)
`external-wallet`	Bring-your-own key (MetaMask, KMS, etc).	All

React / React Native

For React applications, use @crossmint/client-sdk-react-ui which provides wallet providers, hooks (useWallet, useWalletOtpSigner), and built-in UI for OTP and passkey flows.

For React Native, see @crossmint/client-sdk-react-native-ui.

Documentation

License

Apache-2.0