Go SDK - Multi-Agent Transactions

Multi-agent transactions allow multiple accounts to participate in the logic of a Move contract.

This can be used to require multiple parties agree to a transaction before executing or to use resources from multiple accounts.

Creating and executing a multi-agent transaction follows a similar flow to the regular transaction flow, but with several notable differences.

1. Build the transaction by including aptos.AdditionalSigners with a list of each additional signers.

   transaction, err := client.BuildTransactionMultiAgent(alice.AccountAddress(), aptos.TransactionPayload{
     Payload: &aptos.EntryFunction{
       // Replace module and function with your multi-agent function
       Module: aptos.ModuleId{
         Address: aptos.AccountOne,
         Name:    "aptos_account",
       },
       Function: "transfer",
       ArgTypes: []aptos.TypeTag{},
       Args: [][]byte{
         accountBytes,
         amountBytes,
       },
     },
     AdditionalSigners: []aptos.AccountAddress{bob.AccountAddress()},
   })

2. Sign once for each signer.

   You will combine these signatures in the next step.

   aliceAuth, err := rawTxn.Sign(alice)
   if err != nil {
       panic("Failed to sign transaction as sender:" + err.Error())
   }
   bobAuth, err := rawTxn.Sign(bob)
   if err != nil {
       panic("Failed to sign transaction as second signer:" + err.Error())
   }

3. Combine the signatures with the raw transaction to create a multi-agent signed transaction.

   signedTxn, ok := rawTxn.ToMultiAgentSignedTransaction(aliceAuth, []crypto.AccountAuthenticator{bobAuth})

4. Submit the transaction by combining all agent signatures via the aptos.AdditionalSigners parameter.

   submitResponse, err := client.SubmitTransaction(signedTxn)

5. Lastly, wait for the transaction to resolve.

   txnResult, err := client.WaitForTransaction(submitResponse.Hash)

NUMBER_OF_SIGNER_ARGUMENTS_MISMATCH - This happens when you are attempting to do multi-agent signing for a function which does not require that number of accounts. For example, if you try using multiple signatures for a 0x1::aptos_account::transfer function - it only expects one address, and so produces an error when more than one is provided.