Schulcloud-MCP/README.md

# schulcloud-mcp

Read-only access to a [Schulcloud](https://github.com/hpi-schul-cloud) account —
courses, boards, lessons, tasks and files — for **Claude**, via MCP, and for
**you**, via a CLI that mirrors your coursework to disk.

Both are front ends over one core library and one live Schulcloud session, kept
alive on a Pi.

Built and verified against `schulcloud-thueringen.de` with a live student
account. Everything in `docs/API.md` was confirmed against the running
instance, not inferred from the upstream source.

## What Claude can do with it

> *"What do I have due this week?"*
> *"Find the material about Verschlüsselung and explain the Caesar cipher worksheet."*
> *"Summarise the routing lesson from the LF10 course."*

Thirteen tools, all read-only:

| | |
|---|---|
| `whoami` | account, school, roles — also a connectivity check |
| `list_courses` | all courses, with ids |
| `get_dashboard` | the tiles as pinned on the web dashboard |
| `get_course` | one course's boards, topics and tasks |
| `get_board` | a column board in full: columns, cards, text, links, files |
| `get_lesson` | a topic's text sections, materials, files and tasks |
| `list_tasks` | homework across all courses, by due date |
| `get_task` | one task: description, due date, status, attachments |
| `list_files` | files attached to any entity |
| `download_file` | fetch a file and extract its text, or view an image |
| `search` | keyword search across everything — **including the text inside PDFs and Office files** |
| `refresh_index` | re-read Schulcloud now, per course or in full |
| `what_changed` | what appeared, changed or vanished since a date |
| `index_status` | how fresh the index is |
| `list_news` | school and course announcements |
| `api_get` | GET-only escape hatch for uncovered API surface |

`download_file` extracts text from **PDF, DOCX, XLSX, PPTX and OpenDocument**
files and returns **images inline** for Claude to look at. Image-only PDFs —
scans with no text layer, which are common in this account — are reported as
such rather than as an empty result.

## The CLI

```bash
schulcloud login --server https://mcp.example.org --token <token>
schulcloud sync --dry-run      # see what would be mirrored
schulcloud sync                # mirror coursework to ~/Schulcloud
schulcloud refresh --course <id>
```

It talks only to the Pi and holds no Schulcloud credential — see
[docs/CLI.md](docs/CLI.md).

## Quick start

```bash
cp .env.example .env        # fill in TSC_URL and TSC_JWT_COOKIE
npm install
npm run build
npm run probe               # verifies the token and API against the live instance
```

To try it on your own machine — Docker stack, Claude Code, and the CLI — follow
[docs/LOCAL.md](docs/LOCAL.md). To put it on a Pi behind Caddy, see
[docs/DEPLOYMENT.md](docs/DEPLOYMENT.md).

Getting `TSC_JWT_COOKIE` takes four clicks in DevTools and then lasts 30 days —
provided you close the Schulportal window afterwards. See
[docs/AUTH.md](docs/AUTH.md); that caveat is not optional.

## Design decisions

**Bearer token plus a keepalive.** The instance's `jwt` cookie works verbatim
as `Authorization: Bearer` — no cookie jar, no `connect.sid`. Its `exp` claim
(30 days) is only a ceiling: the real limit is a 2-hour server-side session TTL
that any request slides, so the server calls `refresh-session` every 30 minutes
(the one non-GET request here, and not exposed as a tool).

The sharp edge is subtler and cost two endurance tests to find: **the cookie you
copy is the browser's own session token**, so a Schulportal tab left open will
auto-logout after ~2 hours and revoke this server's token with it. Copy the
token in a private window and close it. See [docs/AUTH.md](docs/AUTH.md).

**Read-only by construction.** Every method on the API client is a `GET`,
including `api_get`. The endpoint is internet-facing by necessity (Claude's
connectors call it from Anthropic's cloud), so the fact that a leaked token
cannot be used to *act* as the user is the main safety property. Adding one
write tool would forfeit it.

**An index, with an honest bypass.** Postgres holds crawl generations and a
`german` + `pg_trgm` full-text index over extracted file text, so search covers
the inside of PDFs rather than just their names. Every result states how fresh
the index is, and `fresh=true` bypasses it for a live read — an agent should
never be quietly misled by stale data. Without `DATABASE_URL` the server still
works: search falls back to crawling live.

**Generations, not timestamps.** Sync cursors and change detection compare crawl
generations by identity. Measured: the course-board endpoint returns *request
time* as `updatedAt`, so a timestamp cursor would report everything as changed
on every crawl — and could never detect deletions.

**Assembled, not raw.** `get_board` makes three kinds of upstream call and
stitches the results — board skeleton, card bodies, and a files-storage lookup
per file element — because a model asking "what's on this board" wants the
answer, not a traversal plan. Output is Markdown with ids preserved for
follow-up calls, not raw JSON.

Possible extensions — full-text search over file contents, a cache with a
bypass, "what's new since…" — are sketched with their trade-offs in
[docs/ROADMAP.md](docs/ROADMAP.md). None are built.

## Layout

```
src/
  core/         client, types, board assembly, crawler, extraction, paths
  store/        Postgres: crawl generations, diffs, full-text search
  indexer/      crawl → persist → mirror bytes → extract text → index
  mcp/          MCP server and tools
  http/         express app, bearer auth, /api for the CLI
  cli/          CLI config, API client, sync engine
  bin/          http, stdio and cli entry points
docs/           API findings, auth, deployment, CLI, roadmap
deploy/         Caddyfile snippet
scripts/        probe, smoke, session diagnostics
vendor/         upstream clones, git-ignored, for reference only
```

`core/` knows nothing about MCP, HTTP or the CLI: it holds the Schulcloud client,
the traversal every feature needs, document extraction, and the path
sanitisation that both the server's mirror and the CLI's sync depend on.

## Development

```bash
npm run dev        # watch mode, runs src/ directly
npm test           # unit tests, no network
npm run probe      # check assumptions against the live instance
npm run smoke      # full end-to-end: real server, real client, real data
npm run session-diagnose  # instrument what actually ends the session (~2.5h)
npm run keepalive-status  # is the deployed container holding its session?
npm run typecheck
```

`npm run smoke` starts the HTTP server, connects a real MCP client over
Streamable HTTP and exercises every tool against the live account — 30 checks
covering the auth gate, the protocol handshake, every content chain, file
extraction, `api_get`'s guard rails and error handling.

## Upstream

Reference clones live in `vendor/` (git-ignored):

```bash
git clone --depth 1 --filter=blob:none https://github.com/hpi-schul-cloud/schulcloud-server.git vendor/schulcloud-server
git clone --depth 1 --filter=blob:none https://github.com/hpi-schul-cloud/file-storage.git      vendor/file-storage
git clone --depth 1 --filter=blob:none https://github.com/hpi-schul-cloud/nuxt-client.git       vendor/nuxt-client
```

Most of that organisation's ~100 repositories are archived or superseded; those
three are the live ones that matter. The instance's own OpenAPI documents
(`/api/v3/docs-json`, `/api/v3/file/docs-json`) are more authoritative than any
of them — see [docs/API.md](docs/API.md).