The Python API

The Python API is really just a lower-level of access to what’s going on in the command-line client. The process however is the same: generate, sign, and verify.

Handily, Aletheia has each of these common processes bundled into simple functions that you can import from aletheia.utils.

Generating Keys

To generate keys, simply import can call generate():

from aletheia.utils import generate


Not much to see here. The behaviour is identical to that of the generate command on the command line. Similarly, the location of the generated keys can be altered by setting ALETHEIA_HOME in your environment. See The Command Line API for more details.


Like generating, signing is done with a single function. The only difference is that you must pass in two arguments:

  • The path to the file you want to sign
  • The domain to which you’re ascribing authorship

Have a look at Signing for an explanation as to the importance of that second argument:

from aletheia.utils import sign

sign("/path/to/file.jpg", "")

Bulk Signing

The process of setting up and tearing down Aletheia every time can be avoided by using sign_bulk():

from aletheia.utils import sign_bulk

    ("/path/to/file.jpg", "/path/to/file.mkv", "/path/to/file.html"),


By now this should be looking familiar. Verification is also handled by way of a function:

from aletheia.utils import verify


This will attempt to fetch the public key from the domain stored in the file and then use that public key to verify the file. If you don’t have an internet connection available, and the public key hasn’t already been cached, this process will fail.

Bulk Verification

Just like signing, verification has a bulk helper function:

from aletheia.utils import verify

    ("/path/to/file.jpg", "/path/to/file.mkv", "/path/to/file.html"),

Optional Keyword Arguments

Each of the above commands will accept a series of keyword arguments that will get passed up to the Aletheia class:

  • private_key_path: The path to the private key you want to generate or use to sign a file.
  • public_key_path: The path to where your public key should be generated
  • cache_dir: The path to the directory where you want Aletheia to store all the public keys it caches while verifying files.


from aletheia.utils import generate, sign, verify