The notes existed but there was nowhere to write them: a CLI command on a
laptop, a tool call through Claude, or a file in a Docker volume. None of
those is reachable from a phone in a lesson, which is where notes are
actually taken.
So: `/app`, served only when WEB_PASSWORD is set. A login, the day's
notes, and a settings page for the Schulcloud token — the one surface
here meant for a person rather than a program.
The shape follows how the notes are written: one note per school day,
one `##` heading per lesson, prose and lists and tables beneath. That
turns out to be the design decision that matters, twice over.
First, it is what lets WebUntis earn its keep. Opening a day with no
note fills in that day's lessons — numbered, with times, teacher and
room, cancellations dropped and substitutions marked. Retyping the
timetable is exactly the work the second upstream exists to avoid, and
"Stunden ergänzen" tops up a note started before the day ended without
touching what is already written.
Second, it changes how notes are indexed. A day note is indexed per
lesson, not whole: search answers "my own note, Deutsch, 18.09.2026"
rather than "my own note, Friday", and `list_notes subject=Deutsch`
finds a day whose frontmatter names no subject at all. Indexed whole,
every hit would read as a weekday and "what did we do in Deutsch" would
match notes whose other five lessons were something else. `lessonHeading`
and `subjectFromHeading` are a loop — the app writes the heading, the
indexer reads the subject back out — and a test holds them to it.
Notes taken in a lesson cannot be retaken, so the editor is built
around not losing them: autosave, every keystroke mirrored to local
storage, a save when the phone locks, and a fallback to the local copy
when the request never arrives. A save that would overwrite a version
the editor never saw is refused and the choice handed back — the notes
folder is synced and open in more than one place, and a phone must not
silently win over a laptop. `replaceNote` is separate from `writeNote`
for that reason: never-overwrite is right for `add_note` and exactly
wrong for an editor.
WEB_PASSWORD is the first credential here a human types, so it is the
first that can be guessed: scrypt at startup, never stored or compared
in the clear, per-address rate limiting — which is not decoration, since
the scrypt cost is itself a denial-of-service vector without it. The
session is a signed HttpOnly SameSite=Strict cookie whose key is derived
from the password, so changing it logs everyone out and there is no
second secret to keep. It opens /api, because a session is the user, and
never /mcp, because nothing in a browser speaks MCP.
Also here, because the app made them matter: frontmatter now reads the
indented `- item` list form editors write, so an Obsidian vault
round-trips its tags; and a four-digit folder is a filing scheme, not a
subject, so `2026/` does not file a school year under one.
357 tests; 106/107 smoke against the local instance, the one failure
being the H5P service that instance does not run.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
docs/API.md gains the findings: the endpoint and its required version
parameter, the one-time code and the two error codes worth naming, the Z that
means local time, a substitution being two periods, the unused exam module
that puts announced tests in the period notes, and a day without lessons that
is not a holiday. Those cost an afternoon of probing to learn and nothing
upstream states them.
docs/AUTH.md sets the key against the Schulcloud token it sits beside: no
password, nothing to keep alive, revocable on its own, and not read-only in
itself — which is why the allowlist exists. PI.md and DEPLOYMENT.md add the
four values, the container recreate a changed key needs, and the clock
requirement; the Pi's troubleshooting table gains both failure messages.
README and CLAUDE.md say what the server now is: Schulcloud for the material,
WebUntis for the day. Smoke is 89 checks with the index and a key, 87
live-only, 9 fewer without one.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
claude.ai's connector dialog does offer request headers, on its second step,
after the URL has been probed, so the connector no longer needs the secret
path. MCP_AUTH_TOKEN already worked there as a bearer or X-Api-Key, but it
also opens /api, which can replace the Schulcloud token and stream the file
mirror, and claude.ai stores the header's value.
MCP_CONNECTOR_TOKEN is a second token, accepted on /mcp only and refused on
/api, and rotated without touching Claude Code or the CLI. The config refuses
one shorter than 32 characters, equal to MCP_AUTH_TOKEN, or set without it,
and never echoes a value. Every accepted token is compared in full, so the
timing does not tell which one matched.
The gate also takes a bare Authorization value, because claude.ai sends a
header exactly as typed and its docs warn that most servers reject a token
entered without "Bearer ". It takes X-Auth-Token too, the other name its
dialog offers.
The docs now set up the header; the secret path stays as a fallback for
clients that cannot send one. 184 tests. Smoke 79/79 and 77/77 on the local
instance.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
claude.ai's connector dialog takes a name and a URL. Sending a bearer token
needs a "Request headers" beta most accounts lack, and OAuth is not built
yet, so with MCP_PATH_SECRET set the endpoint is also served at
/<secret>/mcp without the bearer token — a trial until OAuth replaces it.
The path is the credential there. It is compared in constant time, and a
wrong one answers 404 like any unknown path. The config refuses fewer than 32
URL-safe characters and never echoes the value, nothing in the server logs
request paths, and the Caddy snippet rewrites the segment before an access
log entry is written (verified against Caddy 2.11). Claude Code and the CLI
keep the bearer token; DEPLOYMENT.md says what the path trades away.
178 tests. Smoke 76/76 and 74/74 on the local instance.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
A token lasts 30 days and only a browser login yields one — the account is
federated, so the server cannot mint it. Replacing it meant editing .env and
recreating the container, every month.
`schulcloud token set` (a hidden prompt, or piped input) and a /token page
both send it to PUT /api/token. The server checks it with Schulcloud first —
well-formed, unexpired, still logged in, the same account — then swaps it
into the config every request reads, restarts the keepalive and saves it in
STATE_DIR, a new volume, with mode 0600. At startup the newer of the saved
token and TSC_JWT_COOKIE wins, unless they belong to different accounts. A
refused paste changes nothing, and the token is never logged.
The keepalive's pings carry a generation, so a 401 for the old token that
arrives after a swap cannot stop the new cycle. `schulcloud token`, whoami
and the log report the expiry and warn a week ahead.
Found on the way: a host that is off for more than two hours loses the
session however long the token has left — this machine lost it overnight —
which is what the always-on Pi is for.
174 tests. Smoke 72/72 on the local instance, and a real swap verified end to
end there.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Summarises the running container's keepalive: extension count, latest
budget, transient failures, rejections, restarts.
It deliberately makes no API call. Any authenticated request slides the
session TTL, so a checker that talked to Schulcloud would be sustaining
the session itself and could not report on whether the keepalive is
doing it — the same confound that made the first endurance test
ambiguous. Reading container logs observes without participating.
Warns when the reported budget drops below 7000s, which is the early
signal that extensions have stopped taking effect.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Neither of my two hypotheses was right, and the upstream source was
correct all along. The jwt cookie copied from the browser IS the
browser's session token — same jti — so this server and the tab share
one session, and the tab ends it:
1. nuxt-client sets a purely client-side timer, sessionTimeoutTimestamp
= now + JWT_TIMEOUT_SECONDS, reset only on route change
(watch(router.currentRoute, startTimer)) — never by API activity and
never read back from the server's TTL.
2. AutoLogoutWarning.vue warns at JWT_SHOW_TIMEOUT_WARNING_SECONDS.
3. At zero, autoLogout() -> location.replace('/logout?auto-logout=true').
4. schulcloud-client controllers/login.js:439 -> POST /api/v3/logout
-> removeJwtFromWhitelist(jwt) -> the shared key is deleted.
That explains the endurance failure exactly: the GET pings at t+0/30/60/90
were sliding the Valkey TTL correctly, and then the tab deleted the key.
It also explains the ~1h warning dialog appearing in a tab the user
considers in use — the timer only resets on navigation.
So the sliding TTL is real and a keepalive does hold a session to the
30-day ceiling. The operational fix is not to ping harder but to close
the Schulportal window after copying the cookie; a private window is the
tidy way. This is now the loudest caveat in the token-copying steps,
because it is the single easiest way to break the setup.
Keeping refresh-session rather than reverting to GET, now for a reason
that stands on its own: it states the intent contractually instead of
relying on extend-on-check as a side effect of an unrelated read (that
whitelist has been refactored twice in 2026, and a GET keepalive would
fail silently if it went away), and its budget readout makes session
health visible in the log.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The endurance test refuted the sliding-window model I committed earlier.
A keepalive doing only GET /api/v3/me succeeded at t+0/30/60/90 and was
still rejected by t+120 — consistent with the session ending ~2h after
LOGIN (t+107), and inconsistent with 2h after the last request, which
would have been t+210.
This is a live-vs-source divergence, not a misreading: both the current
JwtWhitelistAdapter and the legacy Feathers ensureTokenIsWhitelisted
re-set the Valkey TTL on every authenticated request, so the source
reads as a sliding window. The instance does not behave that way.
So the keepalive now calls POST /authentication/refresh-session, the
endpoint behind the UI's "Sitzung verlängern" button, which a separate
100s test showed does hold the reported budget at 7200s. It is the only
non-GET request in the server: no body, touches only our own session,
cannot read or modify user data, and is not exposed as a tool, so no
model-driven call can ever be a POST. It logs the returned budget, which
makes a failing extension visible before the session is lost.
Whether this is sufficient is NOT established. Two mechanisms still fit:
an idle TTL that reads fail to refresh (keepalive works), or an absolute
cap/revocation anchored at login — e.g. the IDP's back-channel logout,
which clears every token for the account rather than one. Added
scripts/session-diagnose.mjs to settle it: it logs the budget every 10
min, so a decaying series indicates the former and an abrupt 401 at
7200s the latter. Docs state the open question rather than asserting a
mechanism.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The JWT's exp claim says 30 days, and I took that as the session
lifetime. It is only an outer ceiling. The server also keeps a per-token
whitelist entry in Valkey (jwt:{accountId}:{jti}) whose TTL is
JWT_TIMEOUT_SECONDS — 7200s on this instance — and JwtStrategy.validate
re-sets it on every authenticated request. Two hours idle and the token
is rejected with 29 days still on exp.
Proven, not inferred: the token from yesterday returned 401 at 13.8h old.
The live instance publishes the values unauthenticated at
GET /api/v3/config/public — JWT_TIMEOUT_SECONDS 7200,
JWT_SHOW_TIMEOUT_WARNING_SECONDS 3600, the latter being exactly the
one-hour UI prompt that prompted this investigation.
refresh-session turns out not to be special: it extends through the same
guard as any other route, and uniquely only in returning the remaining
TTL. So the keepalive uses GET /api/v3/me instead, and the server stays
GET-only; the one POST in the repo is in scripts/probe.mjs, where it
reports the idle budget.
JWT_EXTENDED_TIMEOUT_SECONDS (~1 month) exists in the config schema but
is vestigial: privateDevice has no references in the current NestJS
source, and generateJwtAndAddToWhitelist never overrides the TTL.
Also fixes a real breakage this surfaced: TypeScript parameter
properties are rejected by Node's type stripping, so `npm run dev` and
`npm test` both failed on any file reaching them. Rewritten as explicit
fields, and noted in CLAUDE.md.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Read-only MCP server exposing a Schulcloud account to Claude: courses,
column boards, lessons, tasks, and file downloads with text extraction.
The API surface was verified against the live instance rather than
inferred from upstream source, which changed several design decisions:
- The `jwt` cookie works verbatim as `Authorization: Bearer` and lasts 30
days, so there is no cookie jar and no refresh-session timer.
- Course contents live at /api/v3/course-rooms/{courseId}/board; there is
no GET /api/v3/courses/{id}.
- Files are a separate service (/api/v3/file/*) with its own OpenAPI doc.
- Board file elements carry no file id; attachments are resolved by
listing files-storage with parentType=boardnodes and the element id.
Read-only by construction: every client method is a GET, including the
api_get escape hatch. The endpoint is internet-facing by necessity, so a
leaked token being unable to act as the user is the key safety property.
Deploys as a container behind the Pi's existing Caddy, guarded by a
constant-time bearer check. Stateless — no database.
Verified: 28 unit tests, plus a 30-check end-to-end run driving a real
MCP client over Streamable HTTP against the live account.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
