Sign and verify with TypeScript - Polygon Developer Docs

Signing uses the active wallet session and does not submit a transaction. Signature verification uses the public wallet API. It can verify an explicit wallet without authentication.

Sign and verify a message

import { Networks } from '@polygonlabs/oms-wallet'

const message = 'Approve checkout order 1042'

const signature = await omsWallet.wallet.signMessage({
  network: Networks.amoy,
  message,
})

const isValid = await omsWallet.wallet.isValidMessageSignature({
  network: Networks.amoy,
  message,
  signature,
})

signMessage requires an active session. When verification omits both walletAddress and walletId, the SDK targets the active wallet ID, so this form also depends on active wallet state.

Verify an explicit wallet publicly

Pass walletAddress or walletId to remove the verification call’s dependency on an active session. The client still needs the project’s publishable key.

import { Networks, OMSWallet } from '@polygonlabs/oms-wallet'

const publicWallet = new OMSWallet({
  publishableKey: 'YOUR_PUBLISHABLE_KEY',
})

const isValid = await publicWallet.wallet.isValidMessageSignature({
  network: Networks.amoy,
  walletAddress: '0x1111111111111111111111111111111111111111',
  message: 'Approve checkout order 1042',
  signature: submittedSignature,
})

This call is read-only and does not establish, restore, or change a wallet session.

Sign and verify typed data

import { Networks } from '@polygonlabs/oms-wallet'

const typedData = {
  domain: {
    name: 'Checkout',
    version: '1',
    chainId: 80002n,
  },
  types: {
    Order: [
      { name: 'orderId', type: 'uint256' },
      { name: 'amount', type: 'uint256' },
    ],
  },
  primaryType: 'Order',
  message: {
    orderId: 1042n,
    amount: 1_000_000n,
  },
} as const

const signature = await omsWallet.wallet.signTypedData({
  network: Networks.amoy,
  typedData,
})

const walletAddress = omsWallet.wallet.walletAddress

if (!walletAddress) {
  throw new Error('No active wallet session')
}

const isValid = await omsWallet.wallet.isValidTypedDataSignature({
  network: Networks.amoy,
  walletAddress,
  typedData,
  signature,
})

typedData is typed as unknown in both public parameter interfaces. The SDK accepts a JSON-compatible typed-data object and converts nested bigint values to decimal strings for the wallet API. Use the same semantic typed data for signing and verification. The explicit walletAddress above makes verification use the public target path, but signTypedData still requires the active session that produced the address. If you already know the target address or wallet ID and signature, you can verify with a newly constructed unauthenticated client as shown for messages. isValidMessageSignature and isValidTypedDataSignature return Promise<boolean>. A false result means the signature did not validate for the supplied target and payload; request or response failures still throw SDK errors.

​Sign and verify a message

​Verify an explicit wallet publicly

​Sign and verify typed data

Sign and verify a message

Verify an explicit wallet publicly

Sign and verify typed data