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Schulcloud-MCP/docs/DEPLOYMENT.md
Fabian Hamm 35125b7683 Initial schulcloud-mcp server
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>
2026-09-11 23:52:12 +02:00

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# Deployment
## The shape of it
```
claude.ai ──HTTPS──▶ VPS (public IP) ──tunnel──▶ Pi 5 (home network)
└─ Caddy ──▶ schulcloud-mcp:8080
└──▶ schulcloud-thueringen.de
```
Claude's custom connectors call the endpoint from Anthropic's cloud, so it must
be publicly reachable over real TLS — a localhost tunnel or self-signed cert
will not do. The VPS provides the public address; Caddy on the Pi terminates
TLS and obtains the certificate.
The container publishes no host port. Caddy reaches it over the shared Docker
network, so the only way in from the internet is through Caddy and then through
this server's bearer check.
## First deploy
```bash
git clone <this repo> /opt/schulcloud-mcp
cd /opt/schulcloud-mcp
cp .env.example .env
# Fill in TSC_URL and TSC_JWT_COOKIE (see docs/AUTH.md), then:
openssl rand -hex 32 # → MCP_AUTH_TOKEN
docker compose up -d --build
docker compose logs -f schulcloud-mcp
```
Expect:
```
[schulcloud-mcp] listening on 0.0.0.0:8080 — instance https://… , auth enabled
```
`auth DISABLED` there means `MCP_AUTH_TOKEN` is empty — fix it before exposing
the service.
## Joining the existing Caddy
The Pi already runs Caddy and PostgreSQL in a Compose project. This server needs
neither a database nor its own Caddy — only a network it shares with the
existing one.
Find the network Caddy is on:
```bash
docker inspect -f '{{range $k,$v := .NetworkSettings.Networks}}{{$k}}{{"\n"}}{{end}}' <caddy-container>
```
Then in `docker-compose.yml`, set that name and mark it external:
```yaml
networks:
caddy:
external: true
name: <the network name you just found>
```
Append `deploy/Caddyfile.snippet` to the Pi's Caddyfile, replacing
`mcp.example.org` with the real hostname, and reload:
```bash
docker exec <caddy-container> caddy reload --config /etc/caddy/Caddyfile
```
Two settings in that snippet matter and are easy to miss:
- **`flush_interval -1`** — MCP's Streamable HTTP transport holds a
server-sent-events channel open. Without this, Caddy buffers it and the
connector hangs with no error.
- **`read_timeout`/`write_timeout` of 300s** — a `search` call walks every
course and can take tens of seconds. Caddy's defaults will cut it off.
## Ports and DNS
- DNS for the hostname points at the **VPS**, not the Pi.
- The VPS forwards 80 and 443 to the Pi's Caddy. Port 80 must work too, or
Caddy cannot complete the ACME HTTP challenge.
- Nothing else needs to be exposed.
## Verifying from outside
```bash
curl -s https://mcp.example.org/healthz
# {"status":"ok","sessions":0}
curl -s -o /dev/null -w '%{http_code}\n' -X POST https://mcp.example.org/mcp \
-H 'content-type: application/json' -d '{}'
# 401 ← the bearer check is live
```
If `/healthz` answers but `/mcp` returns 401 with a correct token, check that
the token in `.env` matches the one in the connector exactly — no trailing
newline from a copy-paste.
## Connecting Claude
1. claude.ai → **Settings → Connectors → Add custom connector**.
2. URL: `https://mcp.example.org/mcp`
3. Under **Advanced settings**, add the bearer token as an authorization
header. If your organisation has no header-auth field, the server also
accepts the token as `X-Api-Key`.
4. Enable the connector in a conversation via **+ → Add connectors**.
Ask *"which courses am I in?"* as a first check — that exercises auth, the
Schulcloud token and the API in one call.
## Running it locally instead
For Claude Code or Claude Desktop on your own machine, skip all of the above and
use stdio:
```json
{
"mcpServers": {
"schulcloud": {
"command": "node",
"args": ["/path/to/schulcloud-mcp/dist/bin/stdio.js"],
"env": {
"TSC_URL": "https://schulcloud-thueringen.de",
"TSC_JWT_COOKIE": "…"
}
}
}
}
```
`MCP_AUTH_TOKEN` is irrelevant in stdio mode — there is no network listener.
## Updating
```bash
cd /opt/schulcloud-mcp && git pull
docker compose up -d --build
docker compose exec schulcloud-mcp node -e "1" # sanity
npm run probe # re-verify the API assumptions
```
## Operational notes
- **Restart policy** is `unless-stopped`; the container comes back after a
reboot.
- **Sessions** are in-memory and dropped after 30 minutes idle. A restart
invalidates them; Claude re-initializes transparently.
- **Logs** are capped at 3 × 10 MB. The Authorization header is never logged.
- **The container is read-only** with `cap_drop: ALL` and
`no-new-privileges`, running as the unprivileged `node` user. It writes
nothing to disk — downloads are streamed through memory, capped at
`MAX_DOWNLOAD_BYTES` (25 MiB default).
- **Monthly chore**: refresh `TSC_JWT_COOKIE`. `npm run probe` tells you how
many days are left.