I14y

Part of the Swiss Public Data MCP Portfolio — a collection of open-source MCP servers connecting AI agents to Swiss public and open data. This is a private project. It is not affiliated with, endorsed by, or operated on behalf of any employer or public authority.

i14y-mcp

License: MIT Python 3.10+ MCP Data: I14Y

MCP server for the I14Y interoperability platform — Switzerland's national metadata catalogue.

🇩🇪 Deutsche Version

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Why this server exists

The other servers in this portfolio answer «what does the data say?». This one answers the question that comes first: «who publishes data on this topic, through which interface, under which licence?»

I14Y is the national data catalogue maintained by the Federal Statistical Office. It describes datasets, registered APIs, public services and harmonised concepts from the Confederation, cantons and communes, using the DCAT-AP-CH profile (eCH-0200).

Mnemonic: «Catalogue before shelf.» Without a catalogue, an agent has to already know a data source exists. With one, it can find it.

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🎯 Anchor Demo Query

«Which authority publishes data on special needs education, through which interface is it available, and under which licence?»

search_catalog(query="Sonderpädagogik")
  → «Statistik der Sonderpädagogik» — Federal Statistical Office (BFS), theme: Bildung

get_dataset(dataset_id=...)
  → 2 distributions, licence: «Opendata BY ASK — attribution required,
    commercial use only with permission from the data supplier»
  → contact: [email protected]

Two tool calls turn a vague topic into a named authority, a download URL and a licence you can act on — get_dataset aggregates the distributions, licences and contact point into one record.

Demo

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Architecture

                 ┌──────────────────────────────┐
                 │      MCP Host (Claude)       │
                 └───────────────┬──────────────┘
                                 │ stdio | streamable-http
                 ┌───────────────▼──────────────┐
                 │          i14y-mcp            │
                 │  ┌────────────────────────┐  │
                 │  │ server.py  (13 tools)  │  │
                 │  ├────────────────────────┤  │
                 │  │ mappers.py             │  │  DCAT → flat, one language
                 │  ├────────────────────────┤  │
                 │  │ models.py  (Pydantic)  │  │  source + provenance envelope
                 │  ├────────────────────────┤  │
                 │  │ client.py              │  │  retry 2s/4s/8s, no-retry 4xx
                 │  └────────────────────────┘  │
                 └───────────────┬──────────────┘
                                 │ HTTPS, no auth
                 ┌───────────────▼──────────────┐
                 │  api.i14y.admin.ch/api       │
                 │  datasets · dataservices ·   │
                 │  concepts · publicservices · │
                 │  catalogs · agents · search  │
                 └──────────────────────────────┘

Architecture decision

This server uses Architecture A (live API only).

Rationale (verified live on 2026-07-21):

• All read endpoints respond without authentication and paginate correctly.
• No bulk download of catalogue metadata is offered, and none is needed.
• Error responses follow RFC 7807, so failure modes are distinguishable.

Consequences:

• Every HTTP call retries transient failures with 2 s / 4 s / 8 s backoff.
• search_catalog caps results client-side because the upstream ignores paging.
• api_status always returns an evaluable state instead of empty records.

Full probe report: docs/probe-i14y.md.

Project phase

This server is in Phase 1 (read-only) of the portfolio's «Read-only First» phase architecture: all tools are read-only, there is no authentication and no personal data. See docs/roadmap.md for the phase model and the prerequisites for any future write capability.

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Tools

Tool	Purpose
search_catalog	Free-text search across the catalogue. Entry point.
list_datasets	Paginated dataset register (complete, unlike search).
get_dataset	Full metadata record for one dataset.
get_dataset_distributions	Download URLs, formats and licences.
list_data_services	Register of official Swiss APIs with endpoint URLs.
get_data_service	Full record for one registered interface.
list_public_services	Administrative services for citizens.
list_concepts	Harmonised concepts and code lists.
get_concept	One concept definition.
search_codelist_entries	Individual codes of a code list.
list_publishers	Publishing bodies, with Swiss UID.
list_catalogs	Contributing catalogues.
api_status	Reachability check with graceful degradation.

All tools are annotated readOnlyHint: true. Write operations exist in the upstream API but are deliberately not exposed.

MCP primitives

This server exposes Tools only — no Resources, no Prompts. That is a deliberate choice, not an omission: I14Y is queried by free-text search and by opaque UUIDs, so there is no small, stable set of addressable URIs that would map cleanly onto MCP Resources, and the server ships no opinionated prompt templates. Every tool is read-only and idempotent; if a future stable entry point emerges (e.g. a fixed theme list) it is a candidate for a Resource.

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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 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.

What the server carries on the modern revision

2026-07-28 moves discovery off the initialize handshake onto server/discover plus a per-request _meta envelope, and gives every cacheable result a freshness hint. What this server puts on those surfaces is measured in tests/test_spec_2026_07_28.py through the assembled stack — and, for stdio, through a real subprocess — rather than read back off the configuration:

Surface	What this server answers
serverInfo, stamped under every modern response	name, display title, description, website, and the installed distribution version — the same version the outbound User-Agent carries
server/discover → instructions	how to sequence the tools, plus the two properties of I14Y that no single tool description shows
ttlMs / cacheScope	300 s, public, on all five cacheable methods this server answers
tools[].title	a display name per tool, so a client shows «Search a concept's code list» rather than search_codelist_entries

The freshness hint is not cosmetic. With none set, the SDK answers ttlMs: 0, cacheScope: private — «already stale, never share» — for directories that are fixed at import and cannot change while the process runs.

Both transports serve the modern revision: HTTP through the streamable-HTTP session manager, and stdio — the default, and what uvx i14y-mcp starts — through the same dual-era loop. Neither is evidence for the other, so both are measured.

One thing this server advertises but does not use. On 2026-07-28 the listChanged flags and resources.subscribe derive solely from whether subscriptions/listen is served, and the SDK wires that handler unconditionally. server/discover therefore reports listChanged: true for a tool list that is fixed at import, and a subscribe capability over an empty resource list; no change notification is ever sent. It is not switchable through the public API — only a wholesale replacement of the server/discover handler could do it, which would be a second truth about our own capabilities — so it is pinned by a test instead of papered over.

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.

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Installation

uvx i14y-mcp

Or from source:

git clone https://github.com/malkreide/i14y-mcp
cd i14y-mcp
pip install -e ".[dev]"

Claude Desktop

{
  "mcpServers": {
    "i14y": {
      "command": "uvx",
      "args": ["i14y-mcp"]
    }
  }
}

Remote deployment (Render, Railway)

I14Y_MCP_TRANSPORT=streamable-http HOST=0.0.0.0 PORT=8000 i14y-mcp

I14Y_MCP_TRANSPORT accepts stdio (the default of the entry point itself), streamable-http (http is a synonym) or sse. The HTTP transports bind to HOST, which defaults to 127.0.0.1 (loopback); set HOST=0.0.0.0 to expose the port on a PaaS (the container image already does both).

Connector URL: https://<host>/mcp

A Claude.ai custom connector speaks Streamable HTTP, and that transport serves exactly one path: /mcp. sse is the older transport and serves /sse and /messages instead — measured through the assembled app, POST /mcp answers 404 there and 200 under Streamable HTTP. The container image therefore defaults to streamable-http; a connector pointed at an SSE deployment gets a 404 and never completes a handshake.

I14Y_MCP_ALLOWED_HOSTS — required for a public deployment

A comma-separated list of the hostnames the server is reached under — hostnames only, no scheme and no port:

I14Y_MCP_ALLOWED_HOSTS=i14y-mcp.up.railway.app,mcp.example.ch

The value is compared literally against the incoming Host header, so https://i14y-mcp.up.railway.app or a trailing :443 matches nothing and every request fails with HTTP 421 Invalid Host header. Behind TLS the browser sends the bare hostname; a non-standard port needs the SDK's only wildcard form, host:*. Loopback stays reachable either way, so container health checks are unaffected.

Leaving it unset on a non-loopback bind does not fall back to something safe. The server cannot guess the name it will be addressed by, and a guessed list would reject every real request, so it switches the Host check off entirely and says so in the log:

dns_rebinding_protection_off

railway.json

railway.json pins the one build setting the deployment cannot get wrong on its own:

{ "build": { "builder": "DOCKERFILE", "dockerfilePath": "Dockerfile" } }

With any other builder Railway never looks at the Dockerfile. It derives a start command itself, I14Y_MCP_TRANSPORT is then set nowhere, and main() falls into the stdio branch — the container runs, never opens a port, and the only trace is a failing health check. tests/test_entrypoint.py fails the day that setting changes.

Two things the file deliberately does not carry:

• No environment variables. Railway's schema has no key for them at any level, so I14Y_MCP_ALLOWED_HOSTS and I14Y_MCP_TRANSPORT belong in the service variables. The trap is that the schema validates values but waves invented keys through: a "variables": { … } block passes validation, your editor stays quiet, and Railway ignores it. A test rejects such a key.
• No healthcheckPath. Measured through the assembled app, no path answers a GET with 2xx: / and /health are 404, /mcp is 400 without a session and 421 under a foreign Host. A health check pointed at any of them would mark the deployment unhealthy and roll it back. The Dockerfile's TCP check does the right thing instead. Should the server ever grow a real health route, the key may be set — a test then requires that the path actually answers.

CORS exposes the Mcp-Session-Id header so browser MCP clients keep their session. Which browser origins may call the server comes from I14Y_MCP_CORS_ORIGINS, a comma-separated list — unset means no browser client is permitted at all, which is the default. * is still accepted and logs a warning. stdio and other non-browser clients are unaffected either way.

Docker

docker compose up --build      # Streamable HTTP on http://localhost:8000/mcp

The image is a hardened multi-stage build: it runs as a non-root user, ships no build tools, and needs no secrets (the API is unauthenticated). See Dockerfile and compose.yaml.

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Join keys

I14Y is a connector layer. Two identifiers make it composable with the rest of the portfolio:

Key	Field	Joins to
Swiss UID	Publisher.uid	register-mcp (Zefix)
Endpoint URL	DataServiceSummary.endpoint_urls	any portfolio server wrapping that API

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Known limitations

Verified live on 2026-07-21.

1. The search index covers roughly half the register. search_catalog returns at most 1013 records; list_datasets reaches about 2003. Use list_datasets when completeness matters.
2. Search returns Datasets only. Filtering by types=["Concept"] or types=["DataService"] yields zero results even though those entities exist. Use list_concepts and list_data_services instead.
3. The upstream ignores paging on search. The full result set is always returned; this server caps it at 200 records and sets truncated: true.
4. Licences vary per distribution, not per dataset. Most carry «Opendata BY ASK», which requires attribution and restricts commercial use. Always read the licence field before reuse.
5. Some metadata fields are simply empty. Frequency, temporal coverage and distribution format are optional and frequently unset by publishers. This is a data-quality property of the catalogue, not a bug in this server.
6. Not every entry with an endpoint has a URL. Entries labelled only «OpenAPI Spezifikation» without a URI are surfaced as (no URI) <label> rather than dropped.

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Testing

PYTHONPATH=src pytest tests/ -m "not live"   # offline, used in CI
PYTHONPATH=src pytest tests/ -m "live"       # hits the real API
PYTHONPATH=src pytest tests/                 # everything
python -m ruff check src tests

The live tests are not decoration: fundstück 4 in the probe report — keywords nesting their language object under label — was caught by a live test after the unit tests were already green.

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Contributing

See CONTRIBUTING.md for the ground rules (read-only, one egress host, no secrets) and the local dev loop. Maintainers: PUBLISHING.md covers the PyPI / MCP Registry release process.

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Security

See SECURITY.md for the security posture and how to report a vulnerability.

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License

MIT License — see LICENSE. The catalogue data remains subject to the terms declared by each publisher.

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Author

Hayal Oezkan · github.com/malkreide

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Credits & related projects

• Data: I14Y Interoperability Platform, Federal Statistical Office (BFS)
• Standard: eCH-0200 / DCAT-AP-CH
• Source discovery inspired by rnckp/awesome-ogd-switzerland
• Portfolio: swiss-public-data-mcp
• Protocol: Model Context Protocol

Licence: MIT. The catalogue data remains subject to the terms declared by each publisher.

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MCP Registry

Ownership marker used by the MCP Registry to link this PyPI package to the GitHub namespace:

mcp-name: io.github.malkreide/i14y-mcp