eth-library-mcp

> 🇨🇭 **Part of the [Swiss Public Data MCP Portfolio](https://github.com/malkreide)**

# 🏛️ eth-library-mcp

![Version](https://img.shields.io/badge/version-0.4.0-blue)
[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
[![Python 3.11+](https://img.shields.io/badge/python-3.11+-blue.svg)](https://www.python.org/downloads/)
[![MCP](https://img.shields.io/badge/MCP-Model%20Context%20Protocol-purple)](https://modelcontextprotocol.io/)
[![Data Source](https://img.shields.io/badge/Data-ETH%20Library%20Zurich-red)](https://developer.library.ethz.ch)
[![CI](https://github.com/malkreide/eth-library-mcp/actions/workflows/ci.yml/badge.svg)](https://github.com/malkreide/eth-library-mcp/actions/workflows/ci.yml)

🌐 **English** | **[Deutsch](README.de.md)**

> MCP server giving AI models direct access to 30M+ resources at ETH Library Zurich – books, maps, images and archival material.

### Demo

![Demo: Claude using eth_search_archive to find historical school documents](docs/assets/demo.svg)

---

## Overview

**eth-library-mcp** connects AI assistants like Claude to the largest natural-science library in Switzerland. It exposes full-text search, archive-level queries and resource-type filtering via the ETH Library's Discovery API – all through a single, standardised MCP interface.

**6 Tools · 1 API · 2 Resources · 2 Prompts**

**MCP Protocol Version:** [`2026-07-28`](https://modelcontextprotocol.io/specification/) (via `mcp[cli]>=2.0.0,<3`).

> **BUG-02 is resolved — by removing the tool.** `eth_search_persons` was documented
> as "currently non-functional, correct URL to be verified". It has now been verified,
> and there is no correct URL: the Persons API is **gone from the gateway**, not merely
> locked. The gateway routes *before* it checks the API key, so an existing route
> answers `401` and a missing one answers `404` — `/discovery/v1/resources` gives 401,
> every `/persons/v1/*` path gives 404, and so does a deliberately invented Discovery
> path used as a control. Offering a capability that cannot exist is the same mistake as
> returning an empty result, only louder. The measurement is recorded and dated in
> [`tests/fixtures/api_routes.json`](tests/fixtures/api_routes.json).

**Anchor demo query:** *"Find historical documents about Zurich school history in the ETH Library archives."*

---

## Features

- 🔍 **Full-text search** over 30M+ resources with fields, operators, and facets
- 📖 **Resource details** – full metadata via MMS-ID
- 🗂️ **Archive search** – ETH University Archives, Max Frisch, Thomas Mann, Graphische Sammlung, Bildarchiv
- 🏷️ **Resource type filter** – books, maps, images, archival material and more
- 🎓 **Education search** – curated workflow optimised for pedagogy and school history
- 📋 **Server overview** – all resource types and archives at a glance
- 🗣️ **Built-in prompts** – structured research and education-research workflows
- ☁️ **Dual transport** – stdio for Claude Desktop, Streamable HTTP/SSE for cloud deployment

---

## Prerequisites

- Python 3.11+
- A free API key from [developer.library.ethz.ch](https://developer.library.ethz.ch)

---

## Installation

```bash
# Clone the repository
git clone https://github.com/malkreide/eth-library-mcp.git
cd eth-library-mcp

# Install
pip install -e .

# Or with uv (recommended)
uv pip install -e .
```

---

## Quickstart

```bash
# Set the API key
export ETH_LIBRARY_API_KEY=your_key_here   # macOS / Linux
# $env:ETH_LIBRARY_API_KEY = "your_key_here"  # Windows (PowerShell)

# Start the server (stdio mode for Claude Desktop)
python -m eth_library_mcp.server
```

> Without an API key the server returns a helpful error message with the registration link – no crashes.

Try it immediately in Claude Desktop:

> *"Find books about Swiss education history in the ETH Library."*
> *"Search the Max Frisch archive for manuscripts about Zurich."*

[→ More use cases by audience →](EXAMPLES.md)

---

## Configuration

### Environment Variables

| Variable | Description | Required |
|---|---|---|
| `ETH_LIBRARY_API_KEY` | API key for the Discovery API | ✅ |
| `ETH_LIBRARY_LOG_LEVEL` | Log level (`DEBUG`/`INFO`/`WARNING`/`ERROR`), default `INFO` | — |
| `ETH_LIBRARY_CORS_ORIGINS` | Comma-separated CORS allow-origins for `--http`. Empty by default: no browser client is permitted. `*` allows any origin and is logged as a warning. Does not affect stdio clients. | — |
| `ETH_LIBRARY_ALLOWED_HOSTS` | Comma-separated hostnames this server is reachable under. Required for a non-loopback bind (`--host 0.0.0.0`): the process cannot derive its own public name, and without this the SDK answers **421 Invalid Host header** to every request. Empty by default; loopback stays reachable either way. | — |

### Claude Desktop Configuration

```json
{
  "mcpServers": {
    "eth-library": {
      "command": "python",
      "args": ["-m", "eth_library_mcp.server"],
      "env": {
        "ETH_LIBRARY_API_KEY": "your_key_here"
      }
    }
  }
}
```

**Config file locations:**
- macOS: `~/Library/Application Support/Claude/claude_desktop_config.json`
- Windows: `%APPDATA%\Claude\claude_desktop_config.json`

### Cloud Deployment (SSE for browser access)

For use via **claude.ai in the browser** (e.g. on managed workstations without local software):

```bash
python -m eth_library_mcp.server --http --port 8000
```

The HTTP transport binds to `127.0.0.1` by default. To expose it on another
interface, pass `--host` explicitly:

```bash
# Only behind a reverse-proxy / firewall that terminates TLS and enforces auth.
python -m eth_library_mcp.server --http --host 0.0.0.0 --port 8000
```

> ⚠️ **Do not bind to `0.0.0.0` without a reverse proxy.** The server has no
> built-in auth, rate-limiting or TLS — any LAN neighbour could call your tools.

> 💡 *"stdio for the developer laptop, HTTP for the browser — behind a proxy."*

---

## Available Tools

### Discovery API (api.library.ethz.ch)

| Tool | Description |
|---|---|
| `eth_search_resources` | Full-text search over 30M+ resources with fields, operators, facets |
| `eth_get_resource` | Full metadata for a specific resource via MMS-ID |
| `eth_search_archive` | Search within a specific archive (University Archives, Max Frisch, Thomas Mann, etc.) |
| `eth_search_by_type` | Filter by resource type (books, maps, images, archival material, etc.) |
| `eth_search_education` | Curated search for education topics (pedagogy, school history, etc.) |

### Utilities

| Tool | Description |
|---|---|
| `eth_library_info` | Server overview: all types and archives at a glance |

### Resources & Prompts

| Item | Type | Description |
|---|---|---|
| `eth://resource-types` | Resource | All available resource types |
| `eth://archives` | Resource | All available archives and collections |
| `research-workflow` | Prompt | Structured research workflow |
| `education-research` | Prompt | Education topics workflow (Schulamt-optimised) |

### Query Syntax

The Discovery API uses structured queries:

```
field,operator,value
```

| Field | Meaning |
|---|---|
| `any` | All fields (recommended for starters) |
| `title` | Title only |
| `creator` | Author / creator |
| `sub` | Subject headings / topics |

| Operator | Meaning |
|---|---|
| `contains` | Term is present |
| `exact` | Exact match |
| `begins_with` | Starts with |

**Examples:**

```
any,contains,Volksschule Zürich
title,contains,Pädagogik
creator,exact,Einstein Albert
sub,contains,Bildungsforschung
title,contains,Schule;sub,contains,Geschichte
```

### Available Archives

| Identifier | Description |
|---|---|
| `ETH_Hochschularchiv` | Institutional memory of ETH Zurich |
| `ETH_MaxFrischArchiv` | Estate of Swiss author Max Frisch |
| `ETH_ThomasMannArchiv` | Letters and documents of Thomas Mann |
| `ETH_GraphischeSammlung` | Prints, drawings, graphic works |
| `ETH_Bildarchiv` | Science/technology history, Swissair (E-Pics) |

### Example Use Cases

| Query | Tool |
|---|---|
| *"Find books about Zurich school history"* | `eth_search_education` |
| *"What's in the Max Frisch archive?"* | `eth_search_archive` |
| *"Find historical maps of Switzerland"* | `eth_search_by_type` |
| *"Get full metadata for resource ID 991170525863705501"* | `eth_get_resource` |
| *"Which archives does the ETH Library hold?"* | `eth_library_info` |

---

## Project Structure

```
eth-library-mcp/
├── src/
│   └── eth_library_mcp/
│       ├── __init__.py        # Package init, version
│       └── server.py          # FastMCP server, all tools
├── tests/
│   └── test_server.py         # Unit tests
├── CHANGELOG.md
├── CONTRIBUTING.md             # Contribution guide (English)
├── CONTRIBUTING.de.md          # Contribution guide (German)
├── SECURITY.md                 # Security posture (English)
├── SECURITY.de.md              # Security posture (German)
├── LICENSE
├── README.md                  # This file (English)
├── README.de.md               # German version
├── claude_desktop_config.json # Example Claude Desktop configuration
└── pyproject.toml             # Build configuration
```

---

## MCP Protocol Version

This server speaks **two protocol eras** over the same endpoint. The client's
first request on a connection decides which one applies; a later claim from the
other era is refused.

| Era | Revision | Who reaches it |
|---|---|---|
| `initialize` handshake | `2024-11-05` … **`2025-11-25`** | What today's clients speak. The server answers with the revision asked for, or with the `2025-11-25` ceiling when the request asks for something newer. |
| Per-request envelope | **`2026-07-28`** | A request carrying the `2026-07-28` `_meta` envelope opens a modern connection. |

Both revisions are pinned in
[`tests/test_protocol_version.py`](tests/test_protocol_version.py) and asserted
against the installed SDK, so a Dependabot bump of `mcp` cannot move either one
silently. The handshake ceiling is measured against a live `initialize` through
the asse