Use an SMS OTP signer as a recovery signer to let users regain access to their wallets when their operational signer is no longer available — for example, when they switch to a new device. The user verifies ownership of their phone number via a one-time password delivered by SMS or optionally WhatsApp, which authorizes the enrollment of a new operational signer.
SMS OTP is a recovery signer, not an operational signer. It is not intended for authorizing day-to-day transactions. The code examples below show how to configure it as the initial signer at wallet creation time, which sets up phone-based recovery for the wallet.
Configuration
React
Node.js
React Native
REST
import { useWallet } from '@crossmint/client-sdk-react-ui';
const { getOrCreateWallet } = useWallet();
const wallet = await getOrCreateWallet({
chain: "base",
signer: {
type: "phone",
phone: "+1234567890"
},
});
import { CrossmintWallets, createCrossmint } from "@crossmint/wallets-sdk";
const crossmint = createCrossmint({
apiKey: "<your-server-api-key>",
});
const crossmintWallets = CrossmintWallets.from(crossmint);
const wallet = await crossmintWallets.createWallet({
chain: "base",
signer: {
type: "phone",
phone: "+1234567890"
},
});
import { useWallet } from '@crossmint/client-sdk-react-native-ui';
const { getOrCreateWallet } = useWallet();
const wallet = await getOrCreateWallet({
chain: "base",
signer: {
type: "phone",
phone: "+1234567890"
},
});
curl --request POST \
--url https://staging.crossmint.com/api/2025-06-09/wallets \
--header 'Content-Type: application/json' \
--header 'X-API-KEY: <x-api-key>' \
--data '{
"chainType": "evm",
"config": {
"adminSigner": {
"type": "phone",
"phone": "+1234567890"
}
}
}'
