3.3.0 is mostly a maintenance and QA release. The major news here is that we've done an AI-based (Claude Fable) review of all the code, this has resulted in quite a lot of hammering on the code to get all the issues found smoothened out.

3.3.0a1 is a variant without any http-library in the dependencies - allowing projects that bring their own http-library to pin a caldav-version that does not bring in niquests.

Breaking changes

The JMAP support has been declared experimental and compatibility_hints.py has been declared unstable, hence the two changes below are deemed allowable in a minor release:

• jmap/client.py and jmap/async_client.py get_objects_by_sync_token(): the newState from CalendarEvent/changes was discarded into _, so callers could not chain sync calls without a separate get_sync_token() round-trip — a race window where intervening changes would be silently missed. The method now returns a 4-tuple (added, modified, deleted, new_sync_token) instead of a 3-tuple.
• compatibility_hints: There has been quite a lot of work refining, calibrating, extending and fixing the compatibility database (and surrounding code). This file is declared unstable for the 3.x release series. The details (wall-of-text) have been omitted. Changes in behaviour may be observed if you have configured your server with features= ...
  • synology
  • robur
  • a hand-rolled features-dict

Added

• Work has been done on the HTTP library support and usage:
  • caldav[niquests] is now a valid install target. Perhaps 4.x will come without any http library in the dependency-list.
  • Installing caldav with no HTTP library at all now fails with a message saying what to install - pip install niquests, or a dependency on caldav[niquests] rather than plain caldav - plus a link to the HTTP Library Configuration documentation. Previously it surfaced as a bare ModuleNotFoundError: No module named 'requests' from somewhere in the import chain. Covers the sync and async CalDAV clients, discovery, caldav.testing and the JMAP clients; the async JMAP client is niquests-only and now says so.
  • The async client can now use httpx2 - Pydantic's continuation of httpx - as its HTTP library. The async fallback chain is niquests, httpx2, httpxyz, then httpx; the first one installed wins, and niquests remains the default and the recommended choice. See also https://github.com/python-caldav/caldav/issues/611
  • The JMAP clients now keep a persistent HTTP session, so connections are reused across requests instead of a fresh TCP+TLS handshake per JMAP call. JMAPClient and AsyncJMAPClient can be used as (async) context managers, and the session can also be released explicitly with client.close() / await client.aclose().
• Infomaniak added to the list of tested servers, with a section in compatibility_hints.py
• caldav.config.extract_conn_params_from_section is now public API (renamed from _extract_conn_params_from_section), so that downstream tools like plann can map plann-style config sections (caldav_url, caldav_user, features, etc.) to DAVClient parameters without duplicating the logic.
• The caldav-server-tester project needs to be able to disable compatibility-workarounds to do its job. New parameters CalendarObjectResource.load(multiget_fallback=True) and Calendar.search(compatibility_workarounds=True). Explicitly set them to False to get more directly to the actual server results.

Changed

• Search results that need loading are now fetched with a single calendar-multiget REPORT instead of one GET per object — a 200-event search made 200 requests before.
• Calendar._create() now discovers and adopts a server-assigned canonical URL after creating a calendar, if the new compatibility feature create-calendar.stable-url is configured as not supported.
• compatibility_hints.py - the derivation logic was always tricky. Now a feature with a default value set is considered to be an independent feature - a feature without a default value is considered to be just a node in the hierarchy, and will derivate its default value from the children. I consider it to be a bugfix, but if you have a hand-written compatibility matrix for your server, things may break.

Fixed

Disclaimer: This section is mostly AI-generated - some of it rewritten by hand, some of it shortened down significantly, but for the most I've just asked the AI to do a better job organizing it and making it short.

Searching

• search.py: the documented operator='==' exact-match guarantee was never enforced.
• search.py: add_property_filter('category', '', operator='undef') queried the nonexistent CATEGORY, and is-not-defined on that matches everything - so it returned every object.
• search.py: the search.combined-is-logical-and: unsupported workaround (triggered on e.g. Nextcloud) was faulty, causing wrong search results.
• The developer hadn't read RFC4791 section 9.7 well enough. Time-range searches and searches with a text attribute would fail towards many servers unless a component type was specified. See https://github.com/python-caldav/caldav/issues/681
• search()'s generator driver now feeds exceptions raised while executing a request back into the search logic, so the server-compatibility fallbacks and per-object load error handling actually take effect (previously dead code). Applies to both the sync and async code paths.

Calendar objects and iCalendar data

• calendarobjectresource.py _complete_recurring_safe(): completing a recurring task would drop the caller-supplied completion_timestamp
• calendarobjectresource.py _get_duration(): a VTODO with a timed DTSTART and no DUE/DURATION got duration = timedelta(days=1) instead of timedelta(0), shifting the next due date by one day when completing a recurring task.
• lib/vcal.py fix(): truncated iCalendar data (no END: line) triggered a bare assert. Now logs a warning and returns the data unchanged instead.
• lib/vcal.py create_ical(): when both alarm_* props and ical_fragment were supplied, the fragment was injected before the first END:V line — which is END:VALARM, placing e.g. an RRULE inside the alarm component. The regex now targets END:V(EVENT|TODO|JOURNAL) specifically.
• lib/vcal.py fix(): the backslash-unescape step used ('\"') as a regex group, which matches only the literal two-character sequence '". A backslash before a lone ' or lone " was silently left in place. Fixed by using the character class ['\"].
• lib/vcal.py fix(): the trailing-whitespace fixup (re.sub(" *$", "", fixed)) lacked re.MULTILINE.
• calendarobjectresource.py change_attendee_status(): calling the method on an event with no ATTENDEE raised a bare KeyError('ATTENDEE') instead of NotFoundError.
• calendarobjectresource.py add_attendee(): "MAILTO:" was not accepted, the scheme check used str.startswith("mailto:") which is case-sensitive. RFC 3986 §3.1 specifies URI schemes are case-insensitive.
• datastate.py RawDataState.get_component_type(): tested for the string "BEGIN:FREEBUSY", but real iCalendar data uses "BEGIN:VFREEBUSY". Any FreeBusy object holding raw data returned component_type=None, causing problems further down. The same typo appeared in the base-class get_uid() and get_component_type() fallback parsers which looked for comp.name == "FREEBUSY" instead of "VFREEBUSY".
• calendarobjectresource.py _set_data(): the raw-string branch cleared the legacy _data/_vobject_instance/_icalendar_instance attributes but never reset self._state, causing data consistency problems in some circumstances.
• vcal.fix(): the COMPLETED date-to-datetime regex consumed the trailing newline, merging the following iCal property into the COMPLETED value on every inbound object from a server that stores COMPLETED as a plain date (e.g. SOGo). Fixed by using a lookahead (?=\s) instead of consuming \s.

Server responses and error reporting

• A response body missing iCalendar (empty object, HTML error page delivered with a 200, a notification carrying only headers, etc) - now raises caldav.lib.error.ResponseError naming the URL and quoting what arrived, instead of letting the icalendar library raise a ValueError. from inside the icalendar library.
• Looking up a calendar or object that does not exist now raises NotFoundError also when the server reports the 404 inside a 207 Multi-Status.

URLs

• collection.py: the ownCloud @-quoting heuristic for a relative calendar-home-set lived in three copies — Principal.calendar_home_set, its async twin, and _sanitize_calendar_home_set_url() used by the PROPFIND extractor — and they had drifted: only the extractor's copy skipped a URL that already contains %40, so a home-set the server delivered part-encoded went through quote() a second time and came back with %2540. All three are now the one helper.
• URL.canonical(): two related bugs — (a) for URLs with an auth part, the canonical form could leak user:pass@ - which again could cause __eq__/__hash__ comparisons to fail. (b) for URLS with no auth part, unauth() returned self and canonical() then overwrote url_raw/url_parsed in place — a bare == or hash() call silently mutated the URL object, potentially re-encoding special characters (e.g. + → %2B) and causing subsequent requests to target the wrong resource.
• _post_put: a 302 response to PUT always raised IndexError instead of following the redirect.

Connections, authentication and rate limiting

• davclient.py and async_davclient.py: rate-limit retry raised TypeError: unsupported operand type(s) for +=: 'NoneType' and 'float' on the second 429 response when the server provides no usable Retry-After value (compute_sleep_seconds returns None). The sleep_seconds += rate_limit_time_slept / 2 line executed before the sleep_seconds is None guard. Now re-raise RateLimitError first, then update the sleep estimate.
• davclient.py DAVClient.__init__(): (a) DAVClient(url='https://user@host/', password='secret') did not work. (b) URL-embedded credentials silently overrode explicit username/password kwargs - now explicit kwargs win. An explicit username discards the URL credentials wholesale rather than merging them field by field — otherwise DAVClient(url='https://bob:hunter2@cal.example.com/', username='alice') would ship alice's login with bob's password. Overriding only the password keeps the URL's username, which stays a coherent pair.
• async_davclient.py: HTML-on-401 diagnostic hint checked self.headers (the client's own request headers) for Content-Type: text/html instead of r.headers, so the intended "server returned an HTML login page, consider setting auth_type" message could never fire.
• lib/auth.py extract_auth_types(): a WWW-Authenticate header ending with a trailing comma (seen in the wild) raised IndexError in the set comprehension because h.split() on an empty segment fails. Added an if h.strip() guard.

Configuration

• config.py resolve_features(): returning a named profile (features='xandikos') returned the module-level dict object directly without copying. Similarly testing.py XandikosServer/RadicaleServer used a shallow .copy(). This was causing mutation-problems.
• config.py get_connection_params(): explicit keyword arguments (e.g. get_davclient(password='secret')) were only respected when url or features was also present. When an env-var or config-file source was found instead, explicit params were silently dropped. Now things are merged. A keyword argument whose value is None counts as "not supplied" rather than "unset it", it's needed to explicitly use an empty string e.g. to override a password from environment with an empty password.
• config.py expand_config_section(): requesting a section name that is absent from the config raised KeyError instead of returning [], causing plain caldav.get_calendars() to crash with KeyError: 'default' on configs with no default section.
• config.py expand_config_section(): disable: true was silently ignored for sections fetched by explicit name or via a contains list — the check used the string literal "section" as the config key instead of the section variable. Only the glob "*" path honoured disable.
• Config file sections with features but no caldav_url were rejected, even though the URL can be derived from the auto-connect.url compatibility hints. Explicitly passed parameters already worked this way; now get_davclient(config_section=...) and friends behave consistently.
• config.py read_config(): only FileNotFoundError was caught while probing the optional config-file locations. With HOME unset (e.g. a Nix build sandbox) the default path expands to //.config//caldav/calendar.conf, which open() rejects with IsADirectoryError; that OSError propagated out of an optional probe, breaking get_davclient() and even crashing pytest's terminal summary renderer. Any OSError (not found, is-a-directory, permission denied) is now treated as "no config here".

The async client, and sync/async parity

• An install with an httpx-family library but no niquests and no requests could not import the async client at all - caldav.async_davclient reached the sync HTTP library through caldav.requests, so the httpx selection succeeded and the import then failed anyway, claiming no supported library was installed.
• async_davclient.py AsyncDAVClient.propfind(): a raw XML body passed as props did not work and caused arbitrary behaviour. This is allowable in the sync DAVClient.propfind(), but it's legacy and serves backward-compatible purposes. Rather than fixing the async code, a TypeError is now raised. XML body should be passed in the body-parameter.
• async_davclient.py _async_request(): when the auth probe got no 401 challenge (an HTML login page, say), the probe response was returned as the real one and the connection error lost.
• collection.py freebusy_request(): on an async client a Principal attendee raised AttributeError - get_vcal_address() returns a coroutine, and it was never awaited.
• async_davclient.py aio.get_calendars(calendar_name=...): the loop iterated a coroutine rather than the calendars, so a lookup by name always came back empty.
• async_davclient.py get_calendars(): lacked the GMX principal-URL fallback present in the sync client.
• collection.py Principal.calendar(cal_id=...): for async clients a bare (non-URL) cal_id/name raised TypeError: argument of type 'coroutine' is not a container or iterable.
• base_client.py get_calendars(calendar_urls=...): a calendar explicitly requested by URL was silently omitted from the result when its displayname property is the empty string "".
• base_client.py, collection.py and async_davclient.py: a calendar whose display name could not be read was silently skipped by a bare except Exception: pass during a lookup by name. The lookup still continues past such a calendar, but it now emits a log.warning unless the server is known not to support propfind.displayname, so an unexpected failure is visible instead of looking like "no such calendar".

JMAP

• jmap/client.py and jmap/async_client.py update_event(): to honour RFC 8620 PatchObject merge semantics, the update null-injects every optional property absent from the new iCalendar so removed properties are actually cleared server-side. This doidn't work out for Stalwart, as it rejects properties it does not support. Workaround applied.
• jmap/client.py and jmap/async_client.py create_task(): a JMAP server response that returned an empty created dict raised a bare KeyError instead of the documented JMAPMethodError.
• jmap/objects/calendar.py JMAPCalendar.search(): datetime arguments for start/end were formatted with a tz-offset for tz-aware non-UTC datetimes. Naive datetimes were copied out verbatim. JMAP requires UTCDate format (YYYY-MM-DDTHH:MM:SSZ). Fixed by converting to UTC and using strftime.
• jmap/convert/jscal_to_ical.py: a recurrenceOverrides entry that does not include a "start" key (the common case — title-only change, description update, etc.) produced a child VEVENT with DTSTART copied from the master event's start time rather than from the override key. This effectively relocated every non-rescheduled override to the master's first occurrence, breaking all override display. Default is now the override key itself.
• jmap/convert/jscal_to_ical.py: EXDATE and RECURRENCE-ID values were always emitted as floating (timezone-less) DATE-TIME regardless of the event's timeZone or showWithoutTime flag. Per RFC 5545 §3.8.5.1 the value type must match DTSTART; a floating EXDATE on a TZID-anchored event does not match any instance, so excluded occurrences reappear. Override keys are now parsed with the event timezone applied (TZID-anchored events) or as date objects (all-day events).
• jmap/convert/_utils.py _format_local_dt(): UTC datetimes produced a Z-suffixed string. RFC 8984 §1.4 defines LocalDateTime (the type required for recurrenceOverrides keys and recurrenceRules.until) as a bare YYYY-MM-DDThh:mm:ss without any suffix; Z-suffixed override keys cannot match LocalDateTime occurrence keys, causing mismatches on strict servers. The function now returns a bare local representation — converted into the event's own timezone first, since a LocalDateTime is local to the event: dropping the offset from a UTC value instead of converting it would shift EXDATE/RECURRENCE-ID/UNTIL by the UTC offset on every TZID-anchored event, and emit a floating UNTIL against a TZID DTSTART, which RFC 5545 §3.3.10 forbids.
• jmap/convert/ical_to_jscal.py and jmap/convert/jscal_to_ical.py: the STATUS property was silently dropped in both conversion directions. STATUS:CANCELLED round-tripped as status: confirmed (JSCalendar default), so cancelled meetings appeared active. Mappings CONFIRMED ↔ confirmed, TENTATIVE ↔ tentative, CANCELLED ↔ cancelled are now implemented.
• jmap/client.py and jmap/async_client.py update_event(): RFC 8620 §3.3 specifies that absent keys in a PatchObject preserve the server value. update_event sent the full converted JSCalendar dict as the patch; properties the caller removed (e.g. LOCATION, VALARM) were absent from the patch and therefore silently persisted on the server. update_event now explicitly sets all optional top-level JSCalendar properties to null when they are absent from the conversion result, ensuring the server removes them.

Packaging and diagnostics

• The source distribution no longer ships stray local files. hatchling's VCS-ignore support only honours the root .gitignore — global gitignore on developers laptop caused caldav-3.2.1.tar.gz to be shipped with .claude/settings.json and 1755 files under venv/, and the current tree would have added 443 files under .prompts/. A new package tox environment (run in CI, and now part of the release procedure) builds both artifacts and fails if anything git does not track turns up in them.
• lib/error.py PYTHON_CALDAV_COMMDUMP: when this debug env-var is set, a logging.warning() is now emitted at import time to remind the operator that request/response bodies and headers (including credentials and calendar PII) are being written to uniquely-named files under /tmp that may accumulate indefinitely.

Security

• response.py: the XML parser is now constructed with resolve_entities=False, no_network=True, so a malicious or MITM server cannot inject arbitrary text into parsed property values through inline DOCTYPE entity definitions. On the lxml versions most people have this was already the effective behaviour (no_network defaults to True, and resolve_entities defaults to 'internal' from lxml 5.0), but lxml is an unpinned dependency and the parser should not be relying on another project's defaults for this.
• discovery.py discover_service(): require_tls=True was not enforced on the well-known URI redirect target — a same-domain Location: http://... passed the domain-validation check and was returned as ServiceInfo(tls=False), allowing a misconfigured or MITM server to silently downgrade the connection to plaintext. Fixed by checking well_known_info.tls against require_tls before returning the result.

The changeset in 3.2.1 is predominantly added async integration tests. Those tests should now be replicating all the logic in the good old sync integration tests under test_caldav.py. Some few more bugs were found while adding those tests.

There are two "feature commits" adding new parameters to existing functions. Those are minor additions and was required while fixing things (test breakage plus observed crash due to weird real-world-data), hence I define this to be a patch-release rather than a minor-release.

Added

• Calendar.delete() has had a "wipe-mode" since v2.2.0, deleting items from the calendar if it's not possible to delete the calendar itself. Now a tristate wipe parameter has been added, wipe=True to wipe rather than delete the calendar, wipe=False to not wipe, and default behaviour (wipe=None) is still "wipe if needed". (Useful for NextCloud tests, where events stuck on calendars in the "trashbin" pollutes the namespace preventing the same event to be added to a new calendar).
• save() only_this_recurrence parameter is now a tristate:
  • True (default) - unchanged, if the object is a recurrence it will be merged with the master event, making sure the saved recurrence is stored as an exception to the RRULE. If the master object does not exist, then it will raise NotFoundError.
  • None (new) - same as True, except that if the master object does not exist, the recurrence will just be sent directly to the server as-is.
  • False - unchanged, the recurrence will be sent directly to the server as-is. None is used in the add_object(). This change was needed to avoid a crash when trying to add a recurrence-object without a master to the server. (So much ado for a very weird edge case).

Fixed

• Async digest auth was broken when using niquests: HTTPDigestAuth.handle_401() calls r.connection.send() which returns a coroutine in async context, causing AttributeError: 'coroutine' object has no attribute 'history'. Fixed by using AsyncHTTPDigestAuth for the async client. See https://github.com/jawah/niquests/issues/387
• Several async code paths were not properly awaited or were missing parity with their sync counterparts:
  • Calendar.freebusy_request() was not async-aware.
  • _async_complete() raised NotImplementedError for handle_rrule=True.
  • _async_put() did not await the retry coroutine returned by _post_put().
  • _async_get_object_by_uid() was missing include_completed=True, unlike the sync version.
  • _async_search_with_comptypes() did not skip component types unsupported by the server, unlike the sync version.
• Zimbra compatibility: DisplayName is now omitted from the MKCALENDAR request body when create-calendar.set-displayname is unsupported.

Changed

• httpxyz added as an async HTTP fallback. httpxyz is a maintained fork of httpx that picked up where httpx stalled. The async client fallback priority is now niquests (preferred) → httpxyz → httpx. See https://github.com/python-caldav/caldav/issues/611

Test framework

These changes are not part of the shipped library, but make up the bulk of the 3.2.1 changeset.

Async tests

• Async integration tests greatly expanded (tests/test_async_integration.py grew by ~1700 lines) to mirror the sync suite in test_caldav.py. Part of git bug bug show e44ee06 aka https://github.com/python-caldav/caldav/issues/667
• Test reliability on Nextcloud and others: While I've been trying to insist on static readable UIDs during the last couple of years, Claude insists on using unique identifiers for each run using uuid4. The latter does improve the reliability when it comes to i.e. Nextcloud that moves calendars to the trashbin rather than deleting them, while also rejecting duplicated UIDs. I finally gave up on this one for some of the event/task/journal UIDs after restarting the nextcloud container every so often to avoid test breakages. I still haven't given up the idea of having static calendar IDs to identify the test calendars.
• testCheckCompatibility no longer takes ~8 minutes on servers with a search-cache delay (e.g. Bedework) — two bugs causing repeated cache-delay waits were fixed, and some redundant Bedework compatibility-matrix entries were cleaned up.
• Added unit and integration tests for the orphaned-recurrence save behaviour (test_caldav.py, test_caldav_unit.py).
• tests/test_servers/: registered Baikal's URL_ENV_VAR so the async-httpx CI job can reach it, and added a get_available_servers() helper used by the async integration tests.

Docker test servers

• Migrated the local test rig from Docker to rootless Podman, which surfaced and fixed several issues:
  • The DAViCal setup script broke on Podman's Emulate Docker CLI using podman banner string.
  • Some health-checks were broken (probably under Docker too, just unnoticed) and were repaired.
  • Removed uid=…,gid=… tmpfs mount options that Podman does not support (CCS / CalendarServer runs as root inside the container, so the ownership hint wasn't needed).
• Stalwart v0.16.6 breaking changes handled: the server now enters bootstrap mode without config files (config files added), the admin API was reorganized (affecting setup calls and health-checks), simple usernames are rejected in favour of full email addresses (testuser@example.org), weak passwords are rejected, and a workaround was added for Stalwart advertising https:// even when reached over http:// in local dev.
• Nextcloud: added mailto: email addresses for the scheduling test users (so iTIP delivery works), and disabled the CalDAV trashbin (calendarRetentionObligation=0) so HTTP DELETE hard-deletes objects and re-using a UID doesn't hit a UNIQUE constraint violation.
• Cyrus: ship imapd.conf with virtdomains: off (the default virtdomains: userid caused 403s on iTIP delivery due to userid/ACL mismatch), unpinned from the March 2026 digest now that :latest is stable again, and pointed the health-check at the CalDAV port.
• Dropped some now-obsolete lines from the Xandikos (in)compatibility matrix following upstream bugfixes.

GitHub CI

• More server coverage in the GitHub workflows: Nextcloud and Cyrus are now configured for the scheduling tests, and a new async-httpx integration job runs against a real Baikal service (previously only unit tests exercised the httpx fallback path).
• Renamed the async (niquests fallback) job to async (niquests) to reflect that niquests is the default install, not a fallback.
• Added CI jobs verifying each async HTTP backend is picked up correctly when the others are absent: async (niquests), async (httpxyz fallback) and async (httpx fallback).
• lychee link-checker upgraded to v0.24.1 (pre-commit hook bumped from v0.22.0). v0.24.1 hard-errors on placeholder URLs like scheme://hostname:port instead of silently rewriting them, which the 30-day cache had been masking — placeholder URLs were replaced with concrete examples (http://proxy.example.com:8080) in davclient.py and async_davclient.py, and .lycheeignore was updated accordingly.

The two most significant news in v3.2 are relatively well-tested support for scheduling (RFC6638) and better-tested support for async. Care should still be taken, those features are backed by many tests, but lacks testing for how well they support real-world use-case scenarios. While async support was added in version 3.0, it was not well-enough tested. Still only a fraction of all the integration tests for sync usage has been duplicated in the async integration test, I expect to release 3.2.1 with symmetric async integration tests before 2025-07.

Added

• add_organizer() now accepts an optional explicit organizer argument (a Principal, vCalAddress, or email string)
• Complete support for Schedule-Tag (RFC 6638 §3.2–3.3) and Etag. Headers from upstream will be caught and stored in the properties. If those properties exists, If-Schedule-Tag-Match or If-Match headers will be sent. A ScheduleTagMismatchError or ETagMismatchError will be raised on 412.

Changed

• httpx deprecation - earlier, in async mode, if httpx was installed it would be used (while niquests is listed in the requirements). This have been reversed - now httpx will be used if it's installed while niquest isn't installed. httpx seems like a dead end, destroyed by drama and intrigues, and now even flagged as a supply chain risk on Reddit. See https://github.com/python-caldav/caldav/issues/611#issuecomment-4278875543
• SEQUENCE property assumed to default to 0 when absent (RFC 5546 §2.1.4). save() then inserts SEQUENCE:1 unless the increase_seqno parameter is set to False.

Fixed

• Bug with inconsistent search()-results - https://github.com/python-caldav/caldav/issues/650
• Compatibility fixing:
  • _resolve_properties() would crash for some disbehaving servers. https://github.com/pycalendar/calendar-cli/issues/114
  • Calendar.get_supported_components() would crash for some servers. https://github.com/python-caldav/caldav/issues/653
  • Fallback code for accept_invite(), decline_invite() and tentatively_accept_invite() when the server does not expose the calendar-user-address-set property. https://github.com/python-caldav/caldav/issues/399
• Quite some code-paths with IO was async-unaware - found and fixed quite many of those. Some places duplicating code seems to be most trivial - but it's something I really want to avoid. There were already places in the code where the async and sync behaviour differed. I've done quite some refactoring to reduce the amount of duplicated code.
• Done some work on get_object_by_uid(), aligning it with the rest of the search API. Closes https://github.com/python-caldav/caldav/issues/586

AI transparency

I've been experimenting with Claude Code over the last few months, concerns have been raised that it may have negatively affected code quality - and indeed, this is probably a major reason why the async support in v3.0 was simply not good enough. I've been working a bit more on the AI-POLICY.md, some of the directions for the future looks like this:

• All work involving new features should primarily be done by hand (AI-assistance allowed for discussing different design decisions, reviewing and fixing trivial bugs in the new code, dealing with trivial TODO-nodes in the handwritten code, etc).
• All prompts should be logged.
• Prompts should be included in the commit message.
• Model and other relevant information on the AI-usage should be included.
• Commit messages should include information on what and how much is AI-generated (with default being "all" or "none" dependent on the commit message trailer)
• Commit messages should include information on why AI was used.
• The AI should be used for Code Review for every release.

The 3.2-release may not be fully up to those standards, as they were made while working on 3.2.

The branch v3.2-development contains "raw" commits, most of the commits are either AI-written (including commit message) or human-written. I've done quite some work trying to squash the commits into fewer commits, in the main branch all the recent commit messages are handwritten, and most of the commits have some notes on how much is AI-generated and why AI-generation was chosen. The manual walk-through of all the commits has been tedious, but useful for QA-purposes. I'm considering this to be the way forward.

I have all relatively fresh communication with Claude in JSON-files, and I was considering to embed them into the repository for increased transparency. Everything considered, I think it would involve too much noise, so I've skipped it as for now. If you want it, I will publish it.

Housekeeping and documentation

• AI-POLICY.md updated - see also the "AI Transparency" subsection
• GitHub exit strategy: Issues are now mirrored in the git repository itself using the git-bug package. I'm not intending to leave GitHub for the foreseeable future, but I don't want to be locked-in or dependent on GitHub - this is a first step towards an "exit strategy".
• Code quality: reduced ruff ignore list (https://github.com/python-caldav/caldav/issues/634) — removed unused imports (copy, lxml.etree, CalendarSet, cdav/dav re-exports, Optional, timezone, Event/Todo type stubs), replaced bare except: clauses with specific exception types (KeyError, AttributeError, Exception where broad catching is intentional), and removed unused local variables.
• async documentation brushed up a bit with bugfixes and disclaimers
• Examples and tests for finding calendar owners - https://github.com/python-caldav/caldav/issues/544
• Added funding.json (https://fundingjson.org/) at the repository root. Closes https://github.com/python-caldav/caldav/issues/608
• Some broken examples and documentation wasn't properly tested - https://github.com/python-caldav/caldav/issues/661

Test framework, compatibility hints, documentation, examples

• Lots of new compatibility feaure hints added (with checking code in the caldav-server-tester tool), including RFC6638-relevant features.
• Some compatibility feature hints have been renamed and moved around. See the "Breaking changes"-section below.
• _AsyncTestSchedulingBase added: async counterpart of _TestSchedulingBase with test_invite_and_respond and test_freebusy; TestAsyncSchedulingFor<Server> classes generated for each server with scheduling_users configured.
• Lots of new test code for the RFC6638-functionality, including setting up extra test users in the docker containers.

Breaking changes

• Some compatibility feature hints have been moved a bit around. This file is still not considered to be a "sharp" part of the libary, otherwise we'd need to bump the version number to 4.0.
  • freebusy-related flags. The rfc6638-freebusy have been moved to scheduling.freebusy, rfc4791-freebusy have been collapsed down into freebusy (instead of freebusy.rfc4791).
  • search.text.by-uid was removed, there is (probably?) no servers supporting one but not the other. (Though the checks on this may be wrong, as workarounds are automatically employed for servers not supporting text search). https://github.com/python-caldav/caldav/issues/586

Highlights:

• Fixups on the async support. Perhaps the "sans-io" design concept wasn't such a great idea - quite some gaps in the async support has been identified and fixed,.
• Multi-server get_calendars(): a single get_calendars() call can now span multiple config-file sections (including glob/wildcard expansion), aggregating calendars from multiple servers into one CalendarCollection. This was the idea (and has been implemented in my plann project for quite some time), but fell short of getting into the v3.0-release.
• Full async tutorial added to the documentation.

Added

• get_icalendar_component() returns a deep-copy of the inner VEVENT/VTODO/VJOURNAL sub-component for read-only inspection, consistent with the get_icalendar_instance() naming convention.
• edit_icalendar_component() context manager yields the inner component for editing and delegates to edit_icalendar_instance() so all borrow/state/save machinery is reused.
• get_calendars() now accepts a config_section value that is expanded via expand_config_section(), so wildcards like "work_*" or "all" resolve to multiple leaf sections; each section gets its own DAVClient and all calendars are aggregated into a CalendarCollection. CalendarCollection now closes all its clients on context-manager exit.
• New config helper: get_all_file_connection_params(config_file, section).
• PYTHON_CALDAV_USE_TEST_SERVER=1 (or testconfig=True) falls back to automatically starting the first available enabled server from the test-server registry when no testing_allowed config section is present. Three new env vars (PYTHON_CALDAV_TEST_EMBEDDED, PYTHON_CALDAV_TEST_DOCKER, PYTHON_CALDAV_TEST_EXTERNAL) control which server categories are eligible. Per-server priority: keys in config files are honoured.
• New caldav/testing.py (shipped with the package): EmbeddedServer, XandikosServer, RadicaleServer — so pip-installed users can use PYTHON_CALDAV_USE_TEST_SERVER=1 without a source checkout.

Fixed

• get_object_by_uid() (and get_event_by_uid(), get_todo_by_uid(), get_journal_by_uid(), and their deprecated aliases) raised TypeError with async clients because search() returned a coroutine that was iterated directly. Fixes https://github.com/python-caldav/caldav/issues/642
• complete() and the save()-recurrence path were not awaited for async clients.
• uncomplete(), set_relation(), get_relatives(), and invite() lacked async dispatch.
• _handle_reverse_relations() called get_relatives() without await, silently returning a coroutine.
• get_calendar() and get_calendars() were missing from the caldav.aio re-export.
• get_calendars(config_section=…) silently ignored calendar_name and calendar_url keys in config sections — they were stripped before reaching the filter logic.
• expand_config_section() was not called when reading the config file, so contains:-style meta-sections had no effect.
• date objects passed to calendar.search() or calendar.searcher() as time-range boundaries now get coerced to UTC datetime before being forwarded to icalendar_searcher, silencing the "Date-range searches not well supported yet" warning.
• XandikosServer.is_accessible() now sends a minimal PROPFIND requesting only {DAV:}resourcetype instead of an implicit allprop, avoiding spurious NotImplementedError log lines from Xandikos during test-server startup.

Tests and documentation

• Full async tutorial added: docs/source/async_tutorial.rst. Covers the same ground as the sync tutorial plus a "Parallel Operations" section demonstrating asyncio.gather(). The sync tutorial now links to it.
• docs/source/configfile.rst has been rewritten and extended; tests for inherits and env-var expansion added.
• docs/source/tutorial.rst rewritten and fixed.
• The caldav-server-tester tool is now documented in the config file guide.
• Design notes on the dual-mode sync/async pattern and its trade-offs added in docs/source/.
• Test server spin-up/teardown tweaked for reliability.
• CI: deptry and lychee link-checker fixups.

Highlight: Reintroducing debug communication dump functionality.

Fixed

• When environment variable PYTHON_CALDAV_COMMDUMP is given, caldav communication is dumped to /tmp - details in https://github.com/python-caldav/caldav/issues/248 . This is regarded as "fix" rather than "feature" as it was introduced in v1.4.0 and accidentally dropped during the v3.0 refactoring. Restored, with the dump logic extracted into a shared helper so both the sync and async code paths benefit. Test code added to make sure it won't disappear again. Fixes https://github.com/python-caldav/caldav/issues/638
• search() raised NotImplementedError when a full calendar-query XML was passed and the server does not support search.comp-type.optional. This is a really rare and deprecated code path, but still NotImplementedError isn't good. Now it falls back to a single REPORT with the XML as-is. Fixes https://github.com/python-caldav/caldav/issues/637

Tests and documentation

• All links to the RFC is now in a canonical format. Links in docstrings and ReST-documentation follows the sphinx-standard. Fixes https://github.com/python-caldav/caldav/issues/635 - pull request https://github.com/python-caldav/caldav/pull/636
• I've decided to try to stick to the conventionalcommits standard. This is documented in CONTRIBUTING.md, and I've added a pre-commit hook for enforcing it (but it needs to be installed through pre-commit ... so I will most likely have to police pull requests manually)
• Some code refactoring in the test code.
• Improved the lychee link testing setup

Highlights:

• Minor bugfix to support old versions of httpx
• New test server docker container: OX
• Minor other fixes and workarounds
• Started working on proper documentation for the 3.x-series

Test runs before release

• Xandikos, Radicale, all docker servers (including OX), an external Zimbra server, but no other external servers.

Added

• OX App Suite included in the docker test servers. Compatibility hints added. To get OX running it's needed to do an extra build step. See tests/docker-test-servers/ox/. However, OX is undertested as both the caldav-server-checker and the test suite does not play well with OX (events with historic DTSTART etc are used, OX doesn't support that).
• New search.unlimited-time-range feature flag with a workaround in search.py that injects a broad time range (1970–2126) for servers that return an empty result set when no time range is specified (but this still doesn't help to OX).

Fixed

• AsyncDAVClient failed to initialize when using httpx < 0.23.0 because proxy=None was unconditionally passed to httpx.AsyncClient which did not accept a proxy keyword argument in older releases. Fixes https://github.com/python-caldav/caldav/issues/632
• Stalwart (like purelymail) includes extra "not found" error data in some responses. This could trigger a spurious "Deviation from expectations found" log error in production, or an assertion failure in debug mode.

Security

• UUID1 was replaced with UUID4 before releasing v3.0 ... some places. Unfortunately I forgot to grep for UUID1 before preparing the release. When UIDs are generated by UUID1, it may embed the host MAC address in calendar data shared with third parties. Switched to UUID4 throughout.

Potentially Breaking Changes

• The compatibility-hint key search.comp-type-optional has been renamed to search.comp-type.optional for consistency with the dotted-key naming convention used elsewhere. If you have this key set in a local server configuration, update it accordingly.

Documentation

Some minor improvements, including a fix for https://github.com/python-caldav/caldav/issues/635 - use canonical RFC-links.

Version 3.0 should be fully backward-compatible with version 2.x - but there are massive code changes in version 3.0, so if you're using the Python CalDAV client library in some sharp production environment, I would recommend to wait for two months before upgrading.

Highlights

• As always, lots of compatibility-tweaking. This release have probably been tested on more server implementations than any earlier version.
• "Black Style" has been replaced with ruff. This causes quite some minor changes to the code.
• Full async support -- New AsyncDAVClient and async domain objects using a Sans-I/O architecture. The same Calendar, Event, Todo, etc. objects work with both sync and async clients.
• Experimental JMAP client -- New caldav.jmap package with JMAPClient and AsyncJMAPClient for servers implementing RFC 8620 (JMAP Core) and RFC 8984 (JMAP Calendars). Note that this is experimental, and the public API may be changed in upcoming minor-releases.
• Overhaul of the official API -- v3.0 comes with an improved, more pythonic and more consistent API, but aims to be fully backeward compatible. Some work has been done on the documentation, but full QA and updates will have to wait for an upcoming patch release.

Test runs before release

• The built-in test-servers, of course: Radicale, Xandikos
• All the docker-based test servers: Nextcloud, Baikal, Bedework, CCS, Cyrus, DAViCal, Davis, SOGo, Stalwart, Zimbra
• External servers and SaaS-providers:
  • ECloud (NextCloud-based - big troubles due to ratelimiting and need for manually "emptying the trashbin")
  • Synology
  • Zimbra Enterprise, hosted by my employer
  • Robur (has some issues with transient errors)
  • Posteo
  • Purelymail (test run takes ages due to delays before search results are ready)

The tests broke with lots of AuthorizationErrors with GMX. The tests were running successfully towards GMX before releasing the last alpha-release. It's probably a transient issue. I don't want to delay the release by doing more research into it.

Breaking Changes

Be aware that some of the 2.x minor-versions also tagged some "Potentially Breaking Changes" - so if you're upgrading i.e. from 2.1, you may want to browse through the "Potentially Breaking Changes" for the intermediate minor releases too.

• Minimum Python version: Python 3.10+ is now required (was 3.8+).
• Test Server Configuration: tests/conf.py has been removed and conf_private.py will be ignored. See the Test Framework section below.
• caldav/objects.py removed -- the backward-compatibility re-export shim has been deleted. Any code doing from caldav.objects import <something> must be updated; all public symbols remain available directly via caldav or from their respective submodules.
• Config file parse errors now raise exceptions -- caldav.config.read_config() now raises ValueError on YAML/JSON parse errors instead of logging and returning an empty dict. This ensures config errors are detected early.

Deprecated

The following have been deprecated and emit DeprecationWarning:

• calendar.date_search() - use calendar.search() instead
• client.principals() - use client.search_principals() instead
• obj.split_expanded - may be removed in a future version
• obj.expand_rrule - may be removed in a future version
• .instance property on calendar objects - use .vobject_instance or .icalendar_instance
• response.find_objects_and_props() - use response.results instead

The save_*-methods are deprecated but do not yet emit warnings (see https://github.com/python-caldav/caldav/issues/71):

• calendar.save_event() - use calendar.add_event() instead
• calendar.save_todo() - use calendar.add_todo() instead
• calendar.save_journal() - use calendar.add_journal() instead
• calendar.save_object() - use calendar.add_object() instead

Methods that fetch data from the server should use the get_ prefix (see https://github.com/python-caldav/caldav/issues/92). The following are deprecated but do not yet emit warnings:

• calendar.event_by_uid() - use calendar.get_event_by_uid() instead
• calendar.todo_by_uid() - use calendar.get_todo_by_uid() instead
• calendar.journal_by_uid() - use calendar.get_journal_by_uid() instead
• calendar.object_by_uid() - use calendar.get_object_by_uid() instead
• principal.calendars() - use principal.get_calendars() instead
• calendar.events() - use calendar.get_events() instead
• calendar.todos() - use calendar.get_todos() instead
• calendar.journals() - use calendar.get_journals() instead
• calendar.objects_by_sync_token() - use calendar.get_objects_by_sync_token() instead

The following check_*_support() methods are deprecated but do not yet emit warnings:

• client.check_dav_support() - use client.supports_dav() instead
• client.check_cdav_support() - use client.supports_caldav() instead
• client.check_scheduling_support() - use client.supports_scheduling() instead (Those methods actively probe the server; is_supported() is a configuration lookup.)

Additionally, direct DAVClient() instantiation should migrate to get_davclient() factory method (see docs/design/API_NAMING_CONVENTIONS.md)

Added

• Experimental JMAP calendar client — new caldav.jmap package providing a JMAP client for servers implementing RFC 8620 (JMAP Core) and RFC 8984 (JMAP Calendars). Features:

  • Synchronous JMAPClient and asynchronous AsyncJMAPClient with mirrored APIs
  • Full calendar + event CRUD (create_event, get_event, update_event, delete_event, search_events)
  • Incremental sync via get_sync_token / get_objects_by_sync_token
  • Task CRUD (draft-ietf-jmap-tasks) via create_task, get_task, update_task, delete_task
  • Bidirectional iCalendar ↔ JSCalendar conversion layer
  • get_jmap_client() factory reads from the same config sources as get_davclient() (env vars, config file)
  • Tested against Cyrus IMAP

• Full async API - New AsyncDAVClient and async-compatible domain objects:

  from caldav.async_davclient import get_davclient
  
  async with await get_davclient(url="...", username="...", password="...") as client:
      principal = await client.get_principal()
      calendars = await client.get_calendars()
      for cal in calendars:
          events = await cal.get_events()
  

• Retry-After / rate-limit handling (RFC 6585 / RFC 9110) -- DAVClient and AsyncDAVClient now expose rate_limit_handle, rate_limit_default_sleep, and rate_limit_max_sleep parameters (this may be specified in the configuration file as well). When rate_limit_handle=True the client automatically sleeps and retries on 429 Too Many Requests and 503 Service Unavailable responses that include a Retry-After header. When rate_limit_handle=False (default) a RateLimitError is raised immediately so callers can implement their own back-off strategy. New caldav.lib.error.RateLimitError has retry_after (raw header string) and retry_after_seconds (parsed float) attributes. https://github.com/python-caldav/caldav/issues/627

• search.is-not-defined.category and search.is-not-defined.dtend -- new client-side workaround sub-features for servers that do not support the CALDAV:is-not-defined filter natively for these properties.

• Base+override feature profiles -- YAML config now supports inheriting from a base profile:

  my-server:
      features:
          base: nextcloud
          search.comp-type: unsupported
  

• Compatibility fixes

  • New feature flags
    • save-load.event.recurrences.exception which is supported if the server stores master+exception VEVENTs as a single calendar object as per the RFC. Stalwart splits them into separate objects. Stalwart recombines the data when doing an expanded search, so expand=True searches now automatically fall back to server-side CALDAV:expand. (Arguably, unsupported here could also mean the exception data was simply discarded. If needed, I'll refine this in a future version)
    • save-load.journal.mixed-calendar - some calendar servers offers a separate journal list.
    • save-load.reuse-deleted-uid - server allows immediate reuse of an uid if the old object has been deleted
    • search.time-range.*.old-dates - test data mostly have historic dates. Calendars are primarily made for future happenings. Some calendar servers does not support searching for things that happened 20 years ago, even for a very small calendar.
    • search.is-not-defined.category and search.is-not-defined.dtend - actually, those are artifacts. The bug was on the client side, not server side. I may delete them in a future release.
  • Fallback for missing calendar-home-set -- client now falls back to the principal URL when calendar-home-set property is not available (e.g. GMX).
  • Load fallback for changed URLs -- CalendarObjectResource.load() now falls back to UID-based lookup when servers change object URLs after a save.
  • Many other tweaks and fixings of the compatibility hints.

• Added python-dateutil and PyYAML as explicit dependencies (were transitive)

• Quite some methods have been renamed for consistency and to follow best current practices. See the Deprecated section.

• Calendar class now accepts a name parameter in its constructor, addressing a long-standing API inconsistency (https://github.com/python-caldav/caldav/issues/128)

• CalendarObjectResource.id property - Returns the UID of calendar objects (https://github.com/python-caldav/caldav/issues/515)

• calendar.searcher() API - Factory method for advanced search queries (https://github.com/python-caldav/caldav/issues/590):

  searcher = calendar.searcher()
  searcher.add_filter(...)
  results = searcher.search()
  ``
  

• Improved API for accessing the CalendarObjectResource properties (https://github.com/python-caldav/caldav/issues/613 ):

  • get_data(), get_icalendar_instance, get_vobject_instance, get_icalendar_component:
    • Returns COPIES of the data
  • edit_* (but no edit_data - the data is an immutable string, should use simply object.data = foo for editing it)
    • Returns a context manager
    • "Borowing pattern" - with obj.get_foo, the client may edit foo, and then obj.save() to send it to the server.

Fixed

• RFC 4791 compliance: Don't send Depth header for calendar-multiget REPORT (clients SHOULD NOT send it, but servers MUST ignore it per §7.9)
• Lots of minor fixes and workarounds were done while trying to run the integration tests for v3.0, most of them fixing new bugs introduced in the development branch, but also new workarounds for server incompatibilities (and better fixing of old workarounds). v3.0 was tested on quite many more servers than v2.2.6.
• Possibly other minor bugfixes addressing old previously unknown bugs - frankly, I've lost the overview. v3.0 has a lot of code changes.
• The is-not-defined filter for CATEGORIES did not work, and for DTEND it did not work for full day events. (this was fixes in the icalendar-searcher, version 1.0.5).

Changed

• Optimilizations on data conversions in the CalendarObjectResource properties (https://github.com/python-caldav/caldav/issues/613 )
• Lazy imports (PEP 562) -- import caldav is now significantly faster. Heavy dependencies (lxml, niquests, icalendar) are deferred until first use. https://github.com/python-caldav/caldav/issues/621
• Search refactored to use generator-based Sans-I/O pattern -- _search_impl yields (SearchAction, data) tuples consumed by sync or async wrappers
• Configuration system expanded: get_connection_params() provides unified config discovery with clear priority (explicit params > test server config > env vars > config file)
• ${VAR} and ${VAR:-default} environment variable expansion in config values
• Test configuration migrated from legacy tests/conf.py to new tests/test_servers/ framework
• Lots of refactored code.
• "Black Style" replaced with ruff
• Compatibility hint matrix has been updated a bit. I'm a bit confused on weather it's due to changes in my caldav-server-tester tool, changed behaviour in newer versions of the servers, or other reasons. Running the integration tests and debugging such issues takes a lot of time and effort.

Security

• UUID1 usage in UID generation may embed the host MAC address in calendar UIDs. Since calendar events are shared with third parties, this may be a privacy concern. A switch to UUID4 has been made some places in the code. (Running a grep just when doing the final touches on the CHANGELOG, I discovered that there is still some UUID1-instances left. It should be safe to change it, but I don't want to delay the release of v3.0.0, so it will have to go into a future v3.0.1 release)

Test Framework

• New Docker test servers:
  • Apple Calendar Server (CCS) - the project was discontinued long ago, but used to be a flagship of compatibility - and I suspect the iCloud server has inheritated some code from this project.
  • DAViCal - an old server, but maintained and one of the more standard-compliant servers. It also has multi-user support.
  • Davis - it's a relative of Baikal
  • Stalwart - a quite new project, mail+calendar, supports JMAP and is funded through NLNet
  • Zimbra - multi-user mail+calendar. Financed through having a non-free "enterprise" version with paid licenses.
• Fixed Nextcloud Docker test server tmpfs permissions race condition
• Added deptry for dependency verification in CI
• The test server framework has been refactored with a new tests/test_servers/ module. It provides YAML-based server configuration: see tests/test_servers/__init__.py for usage
• Added pytest-asyncio for async test support
• Updated Docker configs: Baikal, Cyrus, Nextcloud, SOGo
• Added lychee link-check workflow
• Added convert_conf_private.py migration tool for legacy config format
• New test files: test_lazy_import.py; expanded test_async_davclient.py, test_async_integration.py, test_compatibility_hints.py, test_search.py, test_caldav_unit.py
• Added async rate-limit unit tests matching the sync test suite
• caldav-server-tester: CheckRecurrenceSearch now also verifies implicit recurrence support for all-day (VALUE=DATE) recurring events, marking the feature as fragile (with behaviour description) when only datetime recurring events work.

GitHub Pull Requests Merged

• #607 - Add deptry for dependency verification (also in 2.2.6) -- Tobias Brox (@tobixen)
• #610 - Development for the v3.0-branch - async support and misc -- Tobias Brox (@tobixen)
• #617 - Refactoring the calendar.search -- Tobias Brox (@tobixen)
• #618 - Deprecate DAVObject.name in favor of get_display_name() -- Tobias Brox (@tobixen)
• #622 - Fix overlong inline literal, replace hyphens with en-dashes -- @joshinils
• #623 - More v3.0 development -- Tobias Brox (@tobixen)
• #625 - feat(jmap): add caldav/jmap — JMAP calendar and task client -- Sashank Bhamidi (@SashankBhamidi)
• #626 - docs(jmap): JMAP usage documentation and autodoc stubs -- Sashank Bhamidi (@SashankBhamidi)
• #630 - More v3.0 development -- Tobias Brox (@tobixen)

GitHub Pull Requests Closed (not merged)

• #565 - ADR: HTTPX Async-First Architecture with Thin Sync Wrappers (design exploration; superceded by #610) -- Chris Coutinho (@cbcoutinho)
• #588 - Fix duplicate parameter bug in search() recursive call (superseded by search refactoring in #617) -- Tobias Brox (@tobixen)
• #603 - Playground/new async api design (exploratory work, superceded by #610) -- Tobias Brox (@tobixen)
• #604 - mistake, pull request created from the wrong branch -- Tobias Brox (@tobixen)
• #628 - ISSUE-627: Add handling of Retry-After header for 429 and 503 status codes (code incorporated into master) -- Tema (@temsocial)

GitHub Issues Closed

• #71 - add_object vs save_object (reopened, reverted and closed)
• #128 - Calendar constructor should accept name parameter (long-standing issue) -- Tobias Brox (@tobixen)
• #342 - need support asyncio -- @ArtemIsmagilov
• #424 - implement support for JMAP protocol -- @ArtemIsmagilov
• #457 - Replace requests with niquests or httpx? -- Tobias Brox (@tobixen)
• #509 - Refactor the test configuration again -- Tobias Brox (@tobixen)
• #515 - CalendarObjectResource.id property returns UID -- Tobias Brox (@tobixen)
• #518 - Test setup: try to mute expected error/warning logging -- Tobias Brox (@tobixen)
• #580 - search.py is already ripe for refactoring -- Tobias Brox (@tobixen)
• #589 - Replace "black style" with ruff -- Tobias Brox (@tobixen)
• #590 - calendar.searcher() API for advanced search queries -- Tobias Brox (@tobixen)
• #601 - get_davclient to be importable from caldav -- Tobias Brox (@tobixen)
• #609 - How to get original RRULE when search expand=True? -- JS Moore (@jakkarth)
• #613 - Data representation API for efficient data access -- Tobias Brox (@tobixen)
• #621 - Using niquests makes import unreasonably slow -- @rymdbar
• #627 - Rate-limit / Retry-After handling -- Tema (@temsocial)
• #631 - Cannot create calendar event by AsyncDAVClient (fix implemented, pending user confirmation) -- Oleg Yurchik (@OlegYurchik)

Credits

The following people contributed to this release through issue reports, pull requests, and/or commits:

• @ArtemIsmagilov
• Chris Coutinho (@cbcoutinho)
• @joshinils
• JS Moore (@jakkarth)
• Oleg Yurchik (@OlegYurchik)
• @rymdbar
• Sashank Bhamidi (@SashankBhamidi)
• Tema (@temsocial)
• Tobias Brox (@tobixen)

Time Spent

Since the 2.2.1-release and excluding the JMAP-work done by Sashank, Tobias has spent around 132 hours on this project.

In the 3.0-release, AI-tools have been used for improving quality and speed. My first impression was very good. It seemed like the AI understood the project, and it could fix things faster and better than what I could do myself - I really didn't expect it to create any good code at all. Well, sometimes it does, other times not. Soon enough I also learned that the AI is good at creating crap code, breaking things and Claude is particularly good at duplicating code and code paths. In the end, despite using Claude I've spent more time on this release than what I had estimated. However, I believe I've done a quite thorough work on preserving backward-compatibility while also developing a better API.

From my roadmap, those are the estimates:

• [x] 50 hours for ASync + improved API - fully done
• [x] 23 hours for fixing/closing old issues - fully done
• [ ] 12 hours for documentation - partly done
• [ ] 40 hours for fixing/closing issues related with scheduling in 3.2 - done the davical test server, estimated to take 6 hours.

In addition, lots of time spent on things that aren't covered by the roadmap:

• The caldav-server-tester utility (but none of it into "polishing and releasing" as the roadmap says)
• More docker test servers
• Responding fast to inbound issues and pull requests
• Communication and collaboration
• The release itself (running tests towards lots of servers with quirks - like having to wait for several minutes from when an event is edited until it can be found through a search operation - looking through and making sure the CHANGELOG is complete, etc) is quite tedious and easily takes several days - weeks if it's needed to tweak on workarounds and compatibility hints to get the tests passing.