Substrate (Polkadot)

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": []
  }
}