cardanomsg

Store and retrieve text or JSON in the Cardano blockchain metadata.

Installation

You can install the module using pip:

pip install cardanomsg

Usage

A BlockFrost API account is required (to prevent needing to run the blockchain locally on your PC).

Send message

Send a message in a transaction.

from cardanomsg.transaction import send_message
transaction_hash = send_message("<BLOCKFROST_PROJECT_ID>", "wallet.skey", "<RECIPIENT_ADDRESS>", 1000000, "Hello World")

Send message with label

Send a message with a searchable label in a transaction.

label = uuid.uuid4().int & (1<<32)-1
payload = {
    "id": 12345,
    "text": "Hello World"
}
transaction_hash = send_message("<BLOCKFROST_PROJECT_ID>", "wallet.skey", "<RECIPIENT_ADDRESS>", 1000000, payload, label)

The label must be numeric. Wait 1-3 minutes after submitting the transaction to find your label.

Get message

Get a message from a transaction.

from cardanomsg.transaction import get_message
message = get_message("<BLOCKFROST_PROJECT_ID>", "079112f6a5192c6eeae57de0607d61e07dea864efc2bbad7aa953795a5c56aae")[0].json_metadata

You can also view the message on the blockchain using Cardanoscan.

https://preview.cardanoscan.io/transaction/079112f6a5192c6eeae57de0607d61e07dea864efc2bbad7aa953795a5c56aae?tab=metadata

Summary | UTXOs | Metadata (1)

Metadata Hash: 2f86fa9fdfcb606ab2b5f060bd125848e45187cf2c798ab389e6a9af98ba8ad1
Public Label: 1
Value: "Hello World"

Find message

Find messages using a label.

from cardanomsg.transaction import find_message
messages = find_message(<BLOCKFROST_PROJECT_ID>, 1782959986)
for message in messages:
    print(message.json_metadata)

Find messages using a label on Cardano mainnet, count 10, page 2, sorted by most recent.

from blockfrost import ApiUrls
messages = find_message(<BLOCKFROST_PROJECT_ID>, 123, api=ApiUrls.mainnet, count=10, page=2, order='desc')

The label must be numeric.

Create wallet

Create a wallet.

from cardanomsg.wallet import create
result = create()

Two files will be created: wallet.skey and wallet.addr.

The contents of wallet.skey is the secret key with the following format.

{
  "type": "PaymentSigningKeyShelley_ed25519",
  "description": "Payment Signing Key",
  "cborHex": "<SENDER_SECRET_KEY>"
}

Publishing to PyPi

Use the following steps to publish a new version to PyPi.

1. Update the version number in pyproject.toml and setup.py.
2. Package the distributable: py -m build
3. Upload the package: py -m twine upload dist/*
4. Confirm the new version at https://pypi.org/project/cardanomsg

License

MIT

Author

Kory Becker http://primaryobjects.com