A Pythonic ctypes wrapper around libdatovka, the C client library for the Czech ISDS ("Datové schránky" / Data Box) system.

No compiled extension, no SWIG — this loads libdatovka.so at runtime and exposes a small, high-level surface covering what a typical integration needs: login, list messages, fetch a message with its attachments, mark as read, send a new message, and look up a recipient's data box ID.

from datovka import DatovkaClient, OutgoingDocument

with DatovkaClient(url, username, password) as client:
    for envelope in client.list_received_messages(limit=10):
        print(envelope.message_id, envelope.subject, envelope.sender_name)

    message = client.get_received_message(envelope.message_id)
    for doc in message.documents:
        print(doc.filename, doc.mime_type, len(doc.data), "bytes")

    # Sending a new message needs exactly one is_main=True document.
    with open("smlouva.pdf", "rb") as f:
        pdf_bytes = f.read()
    client.send_message(
        "5drr7us",
        "Smlouva k podpisu",
        [OutgoingDocument("smlouva.pdf", "application/pdf", pdf_bytes, is_main=True)],
    )

    # Live search is rate-limited; prefer an offline directory (e.g. the
    # seznamds package) for routine lookups and use this as a fallback.
    for box in client.find_box_live("Firma s.r.o."):
        print(box["box_id"], box["name"])

• libdatovka8 (the shared library; version 0.8.0 or newer is needed for report_spam() and Envelope.spam_flag — with older versions report_spam() raises NotImplementedError and spam_flag is None) — see the libdatovka packaging
• Python >= 3.9

This wraps a practical subset of libdatovka's ~166 isds_* functions, not the full API: session lifecycle (login/logout/ping), listing received and sent messages, fetching a full message with attachments, marking a message as read, reporting a message as spam (report_spam), sending a new message with attachments (send_message), and recipient lookup via the live fulltext search (find_box_live). The C structs it decodes (isds_envelope, isds_message, isds_document, isds_list, isds_fulltext_result) are modelled field-for-field to match libdatovka/isds.h; extending coverage to more isds_* calls means adding a prototype in datovka/_capi.py and a thin method in datovka/client.py.

LGPL-3.0-or-later, matching libdatovka.