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Signing

Protostar offers two ways of providing the signature:

Default signer​

By default, Protostar uses the StarkCurveSigner class from Starknet.py to sign transactions.

The way of signing used by this class requires providing a private key (for signing) and account contract's address (to fetch the nonce). Depending on what account you use, these can be obtained in different ways. Refer to your account documentation for more details.

Providing account details in Protostar commands​

To provide your account details when running Protostar commands, these arguments should be used

  • --private-key-path - a path to the file containing private key, either in hex (prefixed with '0x') or decimal format.
  • --account-address - your account contract's address on the appropriate network, either in hex (prefixed with '0x') or decimal format.

If you prefer not to store your private key in a file, define a PROTOSTAR_ACCOUNT_PRIVATE_KEY environment variable. Protostar will use that variable for the private key automatically when running commands.

Using a custom signer class​

If your account contract requires a different way of signing, you can create a custom signer class which inherits from BaseSigner abstract class if

To use a custom signer, provide a --signer-class argument when executing Protostar commands.

caution

The custom signer class must not take any arguments in the constructor, since we don't pass any args on instantiation.

The Python file containing this class can be put next to Cairo source code. Protostar synchronizes PYTHONPATH with project's cairo_path. Modules that are dependencies of Protostar (like starknet_py or cairo-lang) should be available for importing by default. If you want to import other custom modules, you should extend PYTHONPATH yourself (https://docs.python.org/3/using/cmdline.html#envvar-PYTHONPATH), when running this command.