Substrate signing - DFNS documentation

Substrate based chains like Polkadot, Kusama and Polymesh support the following signature kinds:

SignerPayload, serialized generic signer payload.

SignerPayload

Signs a generic signer payload. Note: converting the generic signer payload to a signable extrinsic requires fetching metadata from the targeted blockchain. Therefore it’s tied to a specific network rather than the blockchain kind.

Field	Description	Type - Optional
`network`	A supported Substrate network.	String
`kind`	`SignerPayload`	String
`payload`	The unsigned signer payload formatted as JSON or a serialized hex-encoded buffer as shown below.	String or `SignerPayloadJson`

Hex String

{
  "network": "Polymesh",
  "kind": "SignerPayload",
  "payload": "0x0403007f87d29a4746b8e59e347c0598ad811a10c3cd8735d49cf96b75973864c8c98b0475000400386d0f0019000000e143f23803ac50e8f6f8e62695d1ce9e4e1d68aa36c1cd2cfd15340213f3423eb3b9c09f232a12c50f40e023a01f0b86d679b84748cc289534d96861ef611c67"
}

Typescript Example with polkadot{.js}

First install the polkadot{.js} SDK. You can find the full documentation here: https://polkadot.js.org/docs/ Here a code sample to generate a signature via the DFNS TypeScript SDK:

import { ApiPromise, HttpProvider } from '@polkadot/api'
import { EXTRINSIC_VERSION } from '@polkadot/types/extrinsic/v4/Extrinsic'

const walletId = 'wa-6lbfv-9esgj-xxxxxxxxxxxxxxxx'
const wallet = await dfnsClient.wallets.getWallet({ walletId })

const httpProvider = new HttpProvider(process.env.POLKADOT_NODE_URL!)
const api = await ApiPromise.create({
  provider: httpProvider,
  signer: senderWallet,
  noInitWarn: true,
})

const transaction = api.tx.balances.transferKeepAlive('5EwvHZHrKd9WYc3LByzMZW5cmxJt9VMsfYiKg5jCJb8UBfbC', 10000)
const signerPayload: any = transaction.registry.createTypeUnsafe('SignerPayload', [
  transaction,
  { version: EXTRINSIC_VERSION },
])

const res = await dfnsClient.wallets.generateSignature({
  walletId,
  body: {
    kind: 'SignerPayload',
    message: signerPayload.toHex(),
  },
})

SignerPayloadJson

Please refer to the original Polkadot definition for more details: SignerPayloadJson. Note that additional fields will be rejected.

Field	Description	Type - Optional
`address`	ss58-encoded address of the sending account.	String
`blockHash`	The hash of the checkpoint block, hex encoded.	String
`blockNumber`	The checkpoint block number, hex encoded.	String
`era`	The number of blocks after the checkpoint for which a transaction is valid, hex encoded.	String
`genesisHash`	The genesis hash of the chain, hex encoded.	String
`metadataHash`	The metadataHash for the CheckMetadataHash SignedExtension, hex encoded.	String (optional)
`mode`	flag indicating whether to verify the metadata hash or not.	Integer (optional)
`method`	The encoded method with arguments, hex encoded.	String
`nonce`	The nonce for the transaction, hex encoded.	String
`tip`	The tip to increase transaction priority, hex encoded.	String
`version`	The version of the extrinsic.	Integer
`specVersion`	The current spec version for the runtime, hex encoded.	String
`transactionVersion`	The current transaction version for the runtime, hex encoded.	String
`signedExtensions`	The applicable signed extensions for this runtime.	Array<String>

{
  "network": "Polymesh",
  "kind": "SignerPayload",
  "payload": {
    "address": "5H5tTnmLUqRgvTZvTwCdBKYjKLBm2gkp7u38Q9UUdJa8m6rX",
    "blockHash": "0x2ace05e703aa50b48c0ccccfc8b424f7aab9a1e2c424ed12e45d20b1e8ffd0d6",
    "blockNumber": "0x00000000",
    "era": "0x00",
    "genesisHash": "0x2ace05e703aa50b48c0ccccfc8b424f7aab9a1e2c424ed12e45d20b1e8ffd0d6",
    "method": "0x07141f3da32e72ac6eb6cb40d9e757594363a617b2c3964a2b6ec6895c6648f48d500000",
    "nonce": "0x00000000",
    "tip": "0x00000000000000000000000000000000",
    "version": 4,
    "specVersion": "0x006adb7a",
    "transactionVersion": "0x00000007",
    "signedExtensions": []
  }
}

Last modified on July 7, 2026