Asked for: no tutor on a question outside a session. The tutor is handed the
correct answer and told it may explain it, so it is answer-side content — and
once that rule is written down, the same rule catches two bigger holes:
- `GET /questions/bank` returned `correct_answer`, `explanation`,
`option_explanations`, `key_points` and `attending_tip` for every question in
the bank, to any signed-in learner. It is the question manager's listing, but
nothing stopped anyone calling it: the whole answer key, one request away
from the questions it answers. Stems are still listed to everyone; the answer
side now goes only to whoever writes that question.
- The explanation image behind a question was readable by the same rule, with
no attempt behind it.
"Whoever writes it" is one function now — `may_edit_question` — and it means
moderation, authorship, or an editorial grant that reaches where the question
is filed. Everyone else earns the answer by sitting the question, which is what
an attempt is. The bank browse, the search, the session and the review are all
unchanged; the frontend already sends `attempt_id` everywhere it shows an
answer.
The question manager was reachable by a learner with no grant, and would now
load as a bank of stems with every answer field blanked — a broken page rather
than a door that is not theirs. It says so instead.
Also, while looking at where cards surface: the answer review showed neither
the topic reading nor the cards written against a question, though the player
has shown both under the answer for a while — and the review is the one place
a learner goes through everything they got wrong. The list form of that
component fetched its cards and then dropped them on the floor.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TqXevQJhxFrM7jJg82cgZN
Three things landed together; the message names all of them, because a commit
that mentions one is a commit nobody finds the other two in.
**Figures.** Thirty-four JPEG 2000 files — 21 on questions, the rest unattached
in the media library — are WebP now, with `questions.image_path`,
`questions.explanation_image_path` and `media_assets.path` repointed together.
Serving already converted them on the way out, so nothing was broken; this
removes the step and makes what is stored the same thing that is served. The
originals stay: they are the only copy of what came out of the PDF, they cost a
few megabytes between them, and a conversion nobody can undo is not one to run
against a live bank. Paths are found by what the columns say rather than by
listing a bucket, because three tables record them and updating two would be
worse than none.
**The openai SDK is gone.** Ten call sites — one more than the map said, the
Celery article drafter — every one of them a POST with a JSON body, and not one
reading usage, cost, tool calls or logprobs. Every other call to the same proxy
was already plain httpx: embeddings, the ChromaDB embedding function, speech
both ways, model discovery, the vision probe. So this deletes an abstraction
rather than swapping one for another, and leaves one HTTP client instead of
two. `chat()` and `achat()` return the message content; a `ProxyError` carries
the status and the first 500 characters of the body, which is where the proxy
explains itself.
Behaviour is preserved deliberately, including a 600-second fallback timeout
for the four call sites that were running on the SDK's ten-minute default.
Lowering that is a real change and belongs in its own commit.
Proved against the live proxy on both services rather than only against mocks:
a completion, an async completion, a real 400 the vision probe still classifies
as a refusal, 407 models read from the catalogue, and a word read off an image.
**Voice.** A chosen voice is honoured whatever serves it. The prefix check only
accepted a locally served one, so a site adding a hosted voice would offer it
in Settings, save the learner's choice, and then quietly read every question in
the default voice. The list has always come from the database — adding a voice
is a row in Settings → AI models, never a code change.
And the sign-in page stops offering a locked door: `signup-policy` reports
whether registration is open at all, and the Sign up link goes when it is not.
The switch existed and the only way to discover it was to fill the form in.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TqXevQJhxFrM7jJg82cgZN
**Prepared sessions.** Most of this existed: unanswered first, weakest topic
next, wrong-before-right after that, all scaled by what share of the real paper
each topic carries. What it could not do was change with time, say anything
about itself, or be reached without filling in a form.
Evidence now decays on a thirty-day half-life. Exponential rather than a fixed
window because memory has a slope, not a cliff — under a window, 29 days counts
fully and 31 counts for nothing — and because it is memoryless, so an answer's
weight does not shift when unrelated questions are answered, which is what lets
the preview stay a valid forecast. Spring is worth an eighth of last week. Two
things decay: a question's recall probability, drifting towards even rather
than past it, so an old right answer becomes eligible rather than wrong; and a
topic's accuracy, against a prior of two "no idea" answers, which fixes "right
once, known forever".
Strict unanswered-first meant that on a bank of 2,900 nothing was ever
recycled — spaced repetition existed and was unreachable. Review now takes up
to two fifths of a session. And the damping that spread the picks across topics
was applied only to seen material, so a learner with no history was handed the
heaviest domain entire instead of a spread; that was live.
The plan is the product. It is computed, shown, and then the session is built
from that plan's own ids and the plan returned with it, so the two cannot
differ; every figure in it is a tally over the chosen questions rather than a
forecast. No model touches the ranking — a learner asking "why these twenty"
has to get the same answer twice.
**Vision.** The proxy's own `/model/info` says which models can see, so nothing
is hard-coded: 77 report yes, 11 no, and 328 say nothing at all, which means
absent rather than incapable — so those are asked once with an 8px PNG and the
refusal cached. The deployment's main model turns out not to see, and questions
carry figures the learner is looking at, so the tutor was answering about an
image it had never been shown. It routes to a configured tool model now, folds
the description back in as text saying plainly where it came from, and caches
on the bytes because the same figure is re-sent every turn.
Also fixed on the way: `article` was missing from the admin's task list, so
article drafting always ran on the fallback model whatever an administrator
chose; and `.jpx` stem images were sent as JPEG because `mimetypes` guesses
that from the name, so the provider rejected them two hops later.
An administrator must pick a tool model in Settings → AI models. Until then the
tutor says a figure exists that nothing could read, rather than describing one
it cannot see.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TqXevQJhxFrM7jJg82cgZN
Daniel