Schulcloud-MCP/docs/CLI.md

# The `schulcloud` CLI

Browses and mirrors your Schulcloud files from a laptop, by talking to the
schulcloud-mcp server on the Pi.

## Why it goes through the Pi

The CLI never talks to Schulcloud. It holds no `jwt` cookie, no Schulcloud
credential of any kind — only this server's bearer token.

That is not an accident of layering; it solves a real problem. A Schulcloud
session dies after two hours of inactivity, and a CLI process lives for seconds,
so a CLI with its own token would be dead most times you reached for it. The Pi
already keeps one session alive around the clock. Routing through it means one
session, one keepalive, and one place to paste a fresh cookie once a month.

It also means the laptop cannot accidentally end the server's session: nothing
here can call logout.

## Setup

```bash
schulcloud login --server https://mcp.example.org --token <MCP_AUTH_TOKEN> --dir ~/Schulcloud
```

The token is the same `MCP_AUTH_TOKEN` the Claude connector uses — one token
guards both surfaces. `login` verifies it before saving, so a typo fails
immediately rather than on first real use. Config is written to
`~/.config/schulcloud/config.json` with mode `0600`.

`SCHULCLOUD_SERVER`, `SCHULCLOUD_TOKEN` and `SCHULCLOUD_SYNC_DIR` override the
file, for CI or one-off invocations.

## Commands

```
schulcloud status                  how fresh the server's index is
schulcloud ls [--course <id>] [--long]
schulcloud get <fileId> [--out <path>]
schulcloud sync [--dry-run] [--full] [--prune] [--dir <path>] [--jobs <n>]
schulcloud refresh [--course <id>] [--force]
```

`ls --long` prints file ids, which is what `get` takes.

`--course` accepts a **course or a room id** — rooms ("Räume") are mirrored
alongside courses, with their files under the room's name rather than a course's.

`refresh` asks the server to re-read Schulcloud. Pass `--course` when you know
what changed: that is a handful of requests, where a full re-crawl reads every
course. The server refuses a repeat within a minute unless you pass `--force`.
A full re-crawl can take many minutes — the first one downloads every file,
file-manager folders included — so `refresh` starts it and then polls the
server's status, printing a note every half minute, rather than holding one
request open (which Node's fetch abandons after five minutes).

### The server's Schulcloud token (`token`)

```
schulcloud token                   when it expires, and whether the session is alive
schulcloud token set               hand the server a fresh one
```

The monthly chore, with no restart and no `.env` edit:

1. Open a **private window** and log in to Schulcloud.
2. DevTools → Application (Firefox: Storage) → Cookies → `jwt`: copy the value.
3. `schulcloud token set` and paste it at the prompt. The input is hidden.
4. **Close the private window.** Left open, it logs the token out about two
   hours after login (docs/AUTH.md).

Piping works too — `wl-paste | schulcloud token set` — and a pasted cookie
line such as `jwt=…; Path=/` is cleaned up. The token is never a command-line
argument, so it cannot end up in shell history.

The server checks the token with Schulcloud before swapping it in, so a bad
paste changes nothing. It refuses a token that is malformed, expired, already
logged out, or for a different account. A replacement is saved on the server
(`STATE_DIR`), so a restart keeps it, and the keepalive picks it up at once.
The same form lives at `https://<server>/token` for when no terminal is at hand.
The cookie is HttpOnly, so no bookmarklet can read it for you; the DevTools
copy is the step that remains.

### The file manager (`fs`)

The Schulcloud file manager ("Dateien") — Persönliche, Kurs-, Team- and
Geteilte Dateien — browsed like a filesystem, live:

```
schulcloud fs ls [path] [--long]
schulcloud fs tree [path] [--depth <n>] [--max-folders <n>]
schulcloud fs find <name> [--path <path>] [--type file|folder] [--long]
schulcloud fs get <path> [--out <path>] [--force] [--jobs <n>]
```

```console
$ schulcloud fs ls /courses
$ schulcloud fs tree "/courses/FIA24B - SK (Rh)"
$ schulcloud fs find "*Erben*" --path /courses
$ schulcloud fs get "/courses/FIA24B - SK (Rh)/02_Erbrecht" --out ~/Erbrecht
```

The tree is `/my`, `/courses/<course>`, `/teams/<team>` and `/shared`; the
German names ("/Kurs-Dateien") work too. Names may contain `/` — course names
often do — and still resolve; any segment may also be an id from `--long`.

`fs find` matches any part of a name, or, given `*` or `?`, the whole name as
`find -name` does. `fs get` on a folder downloads everything below it, keeps
the structure, and skips files already present at the same size — so re-running
it resumes. Each folder is one page load on the server, so large trees take a
while.

`sync` mirrors these files too, under `<course>/Kurs-Dateien/…`,
`Persönliche Dateien/…`, `Team-Dateien/<team>/…` and `Geteilte Dateien/`, once
the server's index includes them (`INDEX_FILE_MANAGER`, on by default).

## How sync works

It is a **one-way mirror, not a two-way sync**, and that follows from the data
rather than from laziness: Schulcloud file records are immutable — editing a
file upstream produces a *new* record — so there is no content versioning, no
conflict resolution and no merge. "Download what I do not have" is the whole
algorithm.

Local state lives in `.schulcloud-sync.json` at the root of the sync directory,
**keyed by file record id with the path as derived output**. That is what makes
renames cheap: when a teacher renames a board column, the file moves on disk
instead of being downloaded again under a new name and left duplicated under the
old one.

What it checks, and why only that:

- **Size**, not a checksum. The download endpoint exposes no `ETag` and
  Schulcloud publishes no hash, so verifying content would mean re-downloading
  every file to learn what it already told us. Size reliably catches the failure
  that actually happens — a truncated or interrupted download — and costs a
  `stat`.
- Downloads land on a `.part` neighbour and are renamed into place, so an
  interrupted run never leaves a half-file that a later run mistakes for
  complete.

**Deletions are not propagated by default.** A teacher removing a worksheet is
not a reason to destroy your copy of it; `sync` reports those as "gone upstream,
kept". Pass `--prune` to actually delete them.

`--dry-run` prints exactly what would happen, writes nothing, and does not
advance the cursor.

## Cursors

The server's sync cursor is a **crawl generation id**, not a timestamp. This is
deliberate and measured: `GET /course-rooms/{id}/board` returns the *request
time* as `updatedAt` for most elements, so a timestamp cursor would report every
board as changed on every crawl. Comparing generations by identity also detects
deletions, which no timestamp scheme can.

`--since` on the server API accepts an ISO date for convenience, resolved to the
nearest generation — but correctness never depends on it.

If the server no longer recognises your stored cursor it returns `409` rather
than silently treating everything as new, so you are never tricked into
re-downloading the world. Run `sync --full` deliberately in that case.

## Paths

Mirror paths are `Course/Board/Card/filename`, built by `core/paths.ts`.

Every component of that path originates in Schulcloud — course titles, card
titles and filenames are all user-supplied upstream — so each is reduced to a
single safe path component, and the result is re-checked against the sync root
before anything is written. A file named `../../.ssh/authorized_keys` cannot
escape, and `sync` refuses such an entry rather than writing it.