Mantra Tools for Cardano

This tool provides several script-oriented utilities for the Cardano blockchain.

In particular, it posts metadata or mints/burns tokens. By default, it gathers the UTxOs from the address into a transaction with output to that same address, but minting/burning tokens and/or posting metadata in the process. The cost is the minimum network fee for the transaction.

It can also generate scripts, compute script addresses, compute the fingerprint of a token, and download scripts.

Please post questions and issues here.

Command-line options

$ mantra --help

Mantra Cardano tool.

Usage: mantra [--version] [--quiet] COMMAND
  Utilities for Cardano scripts.

Available options:
  -h,--help                Show this help text
  --version                Show version.
  --quiet                  Minimal output.

Available commands:
  bech32-decode            Decode a Bech32 string.
  bech32-encode            Encode a Bech32 string.
  fingerprint              Compute the Bech32 fingerprint of a token.
  info-address             Print information about addresses.
  info-tx                  Print contents of transaction files.
  info-txbody              Print contents of transaction body files.
  info-utxo                Print UTxO information for addresses.
  mint                     Mint batches of Cardano non-fungible tokens.
  script                   Construct a minting script and compute its Policy ID.
  transact                 Submit Cardano metadata or mint Cardano tokens.
  watch-address            Watch transactions at an address.
  watch-coin               Watch transactions for a coin.
  watch-scripts            Download simple and Plutus scripts used as transaction witnesses.

• Mint batches of Cardano non-fungible tokens
  • mantra mint
• Submit Cardano metadata or mint Cardano tokens
  • mantra transact
• Construct a minting script and compute its Policy ID
  • mantra script
• Download information from all blocks and transactions
  • mantra watch-scripts
  • mantra watch-address
  • mantra watch-coin
• Encoding and decoding Bech32 text
  • mantra bech32-decode
  • mantra bech32-encode
• Computing the Bech32 fingerprint of a token
  • mantra fingerprint
• Show information about a transaction file or address
  • mantra info-address
  • mantra info-tx
  • mantra info-txbody
  • mantra info-utxo

Configuration file format

The configuration file contains the basic network information, along with the funds address and location of the verification and signing keys.

Field	Description	Example Value
socketPath	The path to the cardano-node socket.	"/home/myusername/.local/share/Daedalus/testnet/cardano-node.socket"
magic	The network magic: Nothing for mainnet, or Just followed by an integer for a test network.	Just 1097911063
epochSlots	The number of slots in an epoch on the network, generally always 21600.	21600
addressString	The address for the source of UTxOs.	"addr1qq9prvx8ufwutkwxx9cmmuuajaqmjqwujqlp9d8pvg6gupcvluken35ncjnu0puetf5jvttedkze02d5kf890kquh60slacjyp"
verificationKeyFile	Location of the verification key file for the address.	"payment.vkey"
signingKeyFile	Location of the signing key file. This may be /dev/stdin or a Unix pipe instead of an actual file.	"payment.skey"

• Sample configuration for mainnet: sample-mainnet.mantra.
• Sample configuration for testnet: sample-testnet.mantra.

Security considerations

As is the case for any third-party tool that accesses private/signing keys, one should carefully review the source code for maliciousness or security vulnerabilities and verify the provenance of the executable code.

Instead of storing the signing key in a file that is referenced by the configuration file, the tool can read the key from a pipe such as standard input or from a Unix socket. For example, if the key file was encrypted using GnuPG, the following command will pipe the decrypted key into the tool:

gpg -d my-key.skey.gpg | mantra transact my-config.mantra . . .

where the configuration file my-config.mantra has set the signing key to /dev/stdin. Similar, one can use a Unix socket to achieve a similar result:

if [ ! -e payment.skey ]
then
  mkfifo payment.skey
fi
gpg --pinentry loopback --decrypt payment.skey.gpg > payment.skey &

mantra transact my-config.mantra . . .

where the configuration file has set the signing key to the socket payment.skey. Both methods avoid storing the unencrypted key in a disk file.

Installation

This package uses the haskell.nix build system. Simply clone this repository and execute the build command:

nix-build -A mantra.components.exes.mantra -o build

The executable result will be in ./build/bin/mantra.

Alternatively, one can use the cabal install installation approach, which relies on the cabal.project file and which is known to succeed with cabal 3.4.0.0 and ghc 8.10.4.

A docker image is available at https://github.com/wutzebaer/mantra-docker/.

Development environment

Due to quirks in how haskell.nix and cabal.project interact, the following procedure needs to be followed to create a development environment for compiling mantra:

1. Run nix-shell. This takes a while to build unless you set withHoogle = false in shell.nix.
2. Temporarily comment-out the source-repository-package lines in cabal.project.
3. Run cabal build, hoogle, or other development tools defined in shell.nix.

API documentation

See https://functionally.github.io/mantis/ for API documentation.