CLI

To aid you with finding the parameters, argon2-cffi offers a CLI interface that can be accessed using python -m argon2. It will benchmark Argon2’s password verification in the current environment:

$ python -m argon2
Running Argon2id 100 times with:
hash_len: 32 bytes
memory_cost: 65536 KiB
parallelism: 4 threads
time_cost: 3 iterations

Measuring...

45.7ms per password verification

You can use command line arguments to set hashing parameters. Either by setting them one by one (-t for time, -m for memory, -p for parallelism, -l for hash length), or by passing --profile followed by one of the names from argon2.profiles. In that case, the other parameters are ignored. If you don’t pass any arguments as above, it runs with argon2.PasswordHasher’s default values.

This should make it much easier to determine the right parameters for your use case and your environment.