AirPress lets you create, sign and zip PKPass archives for Apple Wallet in runtime memory without a need for temporary files or directories.

From PyPI:

pip install airpress

from airpress import PKPass

# PKPass compressor operates on `bytes` objects as input/output
p = PKPass(
    ('icon.png', bytes(...)),
    ('logo.png', bytes(...)),
    ('pass.json', bytes(...)),
    ...
)
p.sign(cert=bytes(...), key=bytes(...), password=bytes(...))  # `password` argument is optional
_ = bytes(p)  # Creates `bytes` object containing signed and compressed `.pkpass` archive

In most cases you're likely to return pkpass as http response and bytes object is exactly what you need. PKPass will raise human-readable errors in case something is wrong with pass package you're trying to sign and compress.

Accessing PKPass assets that are already added to pass package is as easy as working with dictionary.

Retrieve asset:

icon = p['icon.png']

It can also be used as alternative to add/update asset:

p['icon.png'] = bytes(...)

Remove asset from pass package:

del p['logo.png']

If you don't have your pass type certificate, follow this guide to create one.

Export your developer certificate as .p12 file and convert it into a pair of cert and key .pem files:

openssl pkcs12 -in "Certificates.p12" -clcerts -nokeys -out certificate.pem

openssl pkcs12 -in "Certificates.p12" -nocerts -out key.pem

You will be asked for an export password (or export phrase), you may leave it blank or provide a passphrase. It's this value that you later should supply to PKPass compressor (or leave blank).

In case you'd like to play around with locally stored files, or your server keeps assets in the same file storage as source code, this example shows you how to read locally stored assets as bytes objects, compress pkpass archive and save it to script's parent directory.

import os
from airpress import PKPass


p = PKPass()

for filename in os.listdir(os.getcwd()):
    with open(os.path.join(os.cwd(), filename), 'rb') as f:
    asset = f.read()
    p.add_to_pass_package((filename, asset))

with open(os.path.join(os.path.dirname(__file__), '...your_path_to/key.pem'), 'rb') as f:
    key = f.read()
with open(os.path.join(os.path.dirname(__file__), '...your_path_to/certificate.pem'), 'rb') as f:
    cert = f.read()
    

p.sign(cert=cert, key=key, password=bytes('your_password_123', 'utf8'))

with open('pass.pkpass', 'wb') as file:
    file.write(bytes(p))