Eth Library Mcp

🇨🇭 Part of the Swiss Public Data MCP Portfolio

🏛️ eth-library-mcp

[Version] [License: MIT] [Python 3.11+] [MCP] [Data Source] [CI]

🌐 English | Deutsch

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]

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 (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.

Anchor demo query: "Find historical documents about Zurich school history in the ETH Library archives."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

Installation

# Clone the repositorygit clone https://github.com/malkreide/eth-library-mcp.gitcd eth-library-mcp
# Installpip install -e .
# Or with uv (recommended)uv pip install -e .

Quickstart

# Set the API keyexport 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 →

Configuration

Environment Variables

Claude Desktop Configuration

{  "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):

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:

# 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)

Utilities

Resources & Prompts

Query Syntax

The Discovery API uses structured queries:

field,operator,value

Examples:

any,contains,Volksschule Zürichtitle,contains,Pädagogikcreator,exact,Einstein Albertsub,contains,Bildungsforschungtitle,contains,Schule;sub,contains,Geschichte

Available Archives

Example Use Cases

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.

Both revisions are pinned in 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 assembled ASGI stack, not read off a constant name.

Note that the SDK's LATEST_PROTOCOL_VERSION is an alias for the modern era, not for the handshake era — pinning against it alone would leave the era that current clients actually negotiate free to drift.

Update policy. When the gate fails, do not edit the constant blindly: read the spec changelog between the two revisions, verify the server still behaves, then move the constant, this section, README.de.md and CHANGELOG.md together.

Server identity (serverInfo)

2026-07-28 stamps the server's Implementation block into every modern result under _meta.io.modelcontextprotocol/serverInfo (spec #3002) — earlier revisions carried it only in the initialize result. What used to be a one-time field is now repeated on every call, and version is required.

The SDK fills none of it: "An unversioned server reports an empty version; the SDK never substitutes its own." Measured against the assembled ASGI stack, this server used to answer "version": "" in both eras while server.json told the registry 0.3.4. It now declares:

icons stays unset: this repository ships none, and an invented path would assert a file that does not exist.

Measured, not read back, in tests/test_server_identity.py: the assertions drive a real modern POST through build_http_app(). A look at mcp.version would stay green even if the constructor argument were lost or the SDK stopped stamping at all.

Testing

# Unit tests (no API key required)PYTHONPATH=src pytest tests/ -m "not live"
# Integration tests (API key required)# Live checks against the gateway — these need NO API keyPYTHONPATH=src pytest tests/ -m "live"
# Re-record the route census (writes tests/fixtures/PROVENANCE.md)python scripts/record_fixtures.py

Until 2026-08-08 this repository had no live tests at all — pytest -m live collected zero. Nothing in it had ever been held against the source.

The Discovery payloads still cannot be recorded: the API requires a key, and tests/fixtures/PROVENANCE.md lists them explicitly as NOT RECORDED rather than giving them a date they never had. What is recordable is the contract the source gives up without a key — which routes the gateway serves — and that is exactly what the finding hangs on. The two control_* entries are part of the measurement, not decoration: without them the recording only proves that someone got a 404; with them it proves what the gateway distinguishes.

The two live tests need no key and say something anyway: they report if the Persons API comes back (then the tool should return) or if Discovery loses its route (then five tools are affected).

Safety & Limits

• Read-only: All tools perform HTTP GET requests only — no data is written, modified, or deleted.
• No personal data: The APIs return bibliographic metadata (titles, authors, subjects, identifiers). No personally identifiable information (PII) is processed or stored by this server.
• Authentication: A free API key from developer.library.ethz.ch is required. The key is read from the ETH_LIBRARY_API_KEY environment variable and never logged or transmitted to third parties.
• Rate limits: The ETH Library API enforces rate limits per API key. The server enforces a 30-second timeout per request. Use limit and offset parameters conservatively.
• Data freshness: Results reflect the ETH Library catalogue at query time. No caching is performed by this server.
• Terms of service: Bibliographic metadata is published as Public Domain — free for all uses. API access is subject to the ETH Library Developer Portal terms.
• No guarantees: This is a community project, not affiliated with the ETH Library or ETH Zurich. Availability depends on upstream APIs.

Contributing

Contributions are welcome! See CONTRIBUTING.md (Deutsch) for guidelines.

Security

Read-only, no PII, a single upstream API key, and a fixed egress allow-list of ETH Library endpoints. See SECURITY.md (Deutsch) for the full security posture and accepted-risk decisions.

Changelog

See CHANGELOG.md

License

• Server code: MIT License — see LICENSE
• Bibliographic metadata: Public Domain (no restrictions)
• API documentation: developer.library.ethz.ch

Author

Hayal Oezkan · github.com/malkreide

Powered by Model Context Protocol • 1 API • 6 Tools • 2 Resources • 2 Prompts

Installation

Run via uv's uvx — no clone or manual install needed. Add to your MCP client config (mcpServers for Claude Desktop, Cursor and Windsurf; use a top-level servers key for VS Code in .vscode/mcp.json):

{  "mcpServers": {    "eth-library-mcp": {      "command": "uvx",      "args": [        "eth-library-mcp"      ]    }  }}