Django app providing FeinCMS content types that embed external content via oEmbed. CachedLookup (models.py) fetches and caches arbitrary URLs; contents.py builds the content types on top of it.

• Commit feature by feature. Keep commit messages succinct — don't restate the diff.
• No attribution / co-author trailers in commits.

tox is the source of truth (tox.ini): py310-dj42, py312/py313-dj52 and -djmain. For a quick local run:

uv venv --python 3.13 .venv
VIRTUAL_ENV=.venv uv pip install -e '.[tests]' 'Django>=5.2,<6.0'
.venv/bin/python tests/manage.py test -v2 testapp

Settings live in tests/testapp/settings.py; OEMBED_PROVIDER is pointed at noembed_oembed_provider there (the library's own default is embedly).

Tests that talk to the real provider are marked @tag("live") and excluded from the tox run via --exclude-tag=live. The "Live provider" job in tests.yml runs them once per workflow run with continue-on-error: true, so a provider outage is reported without blocking a merge. Run them by hand with:

.venv/bin/python tests/manage.py test -v2 --tag=live testapp

• Merge-blocking tests must not touch the network. CachedLookup.clean() calls urlopen(), so patch feincms_oembed.models.urlopen with a fake response object exposing read() and getcode(). Coverage of the real service belongs in a @tag("live") test instead — mocking everything would hide the provider dying, which is the one failure the package cannot work around.
• noembed.com — the provider the test settings use — is unreliable. It intermittently answers {"error": "Can't use string (\"servers\") as a HASH ref ..."} instead of oEmbed data. This is not deterministic per URL: in run 34889438323 the py312 job got a good response for the Rick Astley URL while py313 got the error for the same URL minutes later. Swapping in a video that "works" today only hides the problem — mock instead.
• Matrix jobs failing on only some Python versions has so far always meant this flakiness, not a Django/Python incompatibility. Check whether the failing assertion depends on a network call before hunting for version issues.