Sending bulk transactions

It is easy to prepare a set of transaction and then send them all at once using erdpy. Here's how.

The example in this guide is tailored for missions on the Battle of Nodes.

Requirements:

  • You must have erdpy installed on your computer. See Installing erdpy for details.

  • You need a wallet that contains sufficient eGLD. We will use the mnemonics you have for this wallet to generate a PEM file that erdpy needs.

There will be 3 steps to fulfill:

  1. Prepare the PEM file from the wallet mnemonics.

  2. Prepare the transaction set, which involves you configuring a Bash script (provided below). This script will contain your desired transactions and will reference your PEM file.

  3. Execute the command that sends all the transactions in the prepared set.

Make sure your terminal is running bash, and not zsh or any other shell. Run the following command:

ps -p $$

It should print something like:

PID TTY TIME CMD
169860 pts/6 00:00:00 bash

The word under the CMD keyword must be bash, otherwise the script provided below will not work. If it says zsh, csh, tcsh or anything else, run the following command to start a bash session:

exec /bin/bash

Step 1: Prepare the PEM file

See the page Deriving the Wallet PEM file for how to prepare a PEM file. Make sure you know exactly where erdpy saved it for you.

Step 2: Prepare the transaction set

The following Bash script defines a set of 9 example transactions. Each transaction is on one line, and contains the receiver wallet address (such aserd1qx22...), then a space, then the eGLD amount to be transferred (for example 8). The script will take care of applying the correct eGLD denomination.

You must change the value of MYWALLET first. The wallet you see in the script below doesn't actually exist and transactions sent from it will fail. Therefore you need to write your wallet address between the quotation marks " on the line where MYWALLET is defined.

Next, you must change the PEM_FILE variable to the path to the PEM file you prepared at Step 1 (see above).

Next, you must change the TRANSACTIONS list with the receiver wallets you want, and the amounts you want to transfer. You can delete some of the lines in this list, or add more if you want.

# You must edit the values of MYWALLET and PEM_FILE
# and then modify the TRANSACTIONS list.
MYWALLET="erd1sg4u62lzvgkeu4grnlwn7h2s92rqf8a64z48pl9c7us37ajv9u8qj9w8xg"
PEM_FILE="./walletKey.pem"
declare -a TRANSACTIONS=(
"erd1qx22s3yyawvfvsn3573r3nkwk6c9efj756ex5cnqk5ul6fz5nggqhaze4y 2"
"erd1qx22s3yyawvfvsn3573r3nkwk6c9efj756ex5cnqk5ul6fz5nggqhaze4y 4"
"erd1qx22s3yyawvfvsn3573r3nkwk6c9efj756ex5cnqk5ul6fz5nggqhaze4y 8"
"erd1nuxuu4s07m0348tacnu7et3x9dsskj6rql3yax2qsmct8uux3qqqf86kl9 16"
"erd1nuxuu4s07m0348tacnu7et3x9dsskj6rql3yax2qsmct8uux3qqqf86kl9 32"
"erd1nuxuu4s07m0348tacnu7et3x9dsskj6rql3yax2qsmct8uux3qqqf86kl9 64"
"erd1a6wdtlr72ejdf8szvxaz4xvtcq8650az9005s9s92n7vpkj0lylsmja0h0 128"
"erd1a6wdtlr72ejdf8szvxaz4xvtcq8650az9005s9s92n7vpkj0lylsmja0h0 256"
"erd1a6wdtlr72ejdf8szvxaz4xvtcq8650az9005s9s92n7vpkj0lylsmja0h0 512"
)
# DO NOT MODIFY ANYTHING FROM HERE ON
PROXY="https://api.elrond.com"
DENOMINATION="000000000000000000"
# We recall the nonce of the wallet
NONCE=$(erdpy account get --nonce --address="$MYWALLET" --proxy="$PROXY")
function send-bulk-tx {
for transaction in "${TRANSACTIONS[@]}"; do
set -- $transaction
erdpy --verbose tx new --send --outfile="bon-mission-tx-$NONCE.json" --pem=$PEM_FILE --nonce=$NONCE --receiver=$1 --value="$2$DENOMINATION" --gas-limit=50000 --proxy=$PROXY
echo "Transaction sent with nonce $NONCE and backed up to bon-mission-tx-$NONCE.json."
(( NONCE++ ))
done
}

Save the above code into a file called transactions.sh. We will need it in the next step.

Step 3: Send the transactions

Let's send the transactions:

source ./transactions.sh
send-bulk-tx

The first command imports the send-bulk-tx command from the transactions.sh file (see the file in step 1 above). Then the second command executes send-bulk-tx, which will call erdpy for each of the transactions in the set.

Done!