bag-epl-mcp

> \U0001f1e8\U0001f1ed **Part of the [Swiss Public Data MCP Portfolio](https://github.com/malkreide)**

# \U0001f48a bag-epl-mcp

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> MCP Server for the Swiss BAG electronic benefits platform (ePL) — Spezialitaetenliste, GGSL, MiGeL

[\U0001f1e9\U0001f1ea Deutsche Version](README.de.md)

### Demo

![Demo: Claude using epl_sl_suche and epl_rechtskontext](docs/assets/demo.svg)

---

## Overview

`bag-epl-mcp` enables AI models to answer questions about mandatory health insurance coverage in Switzerland — in natural language, grounded in real data.

| List | Purpose | Legal basis |
|------|---------|-------------|
| **Spezialitaetenliste (SL)** | Compulsory-insurance medications | KVG Art. 52 |
| **GGSL** | Medications for congenital disorders (IV) | IVG Anhang |
| **MiGeL** | Medical devices & aids | KLV Art. 20 |

**Anchor query:** *"Is this medication covered by mandatory health insurance?"*
→ `epl_sl_suche`: Live lookup in the Spezialitaetenliste (SL)
→ [More use cases by audience →](EXAMPLES.md)

---

## Features

- \U0001f48a **6 tools, 2 resources, 2 prompts** for Swiss health insurance data
- \U0001f50d **`epl_sl_suche`** — search the Spezialitaetenliste for medications
- ⚖️ **`epl_rechtskontext`** — legal context with Fedlex links
- \U0001f513 **No API key required** — all data publicly accessible
- ☁️ **Dual transport** — stdio (Claude Desktop) + Streamable HTTP (cloud)
- \U0001f4da **Prompt templates** for insurance coverage checks and school health queries

---

## Prerequisites

- Python 3.11+
- [uv](https://github.com/astral-sh/uv) (recommended) or pip

---

## Installation

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

# Install
pip install -e .
# or with uv:
uv pip install -e .
```

Or with `uvx` (no permanent installation):

```bash
uvx bag-epl-mcp
```

---

## Quickstart

```bash
# stdio (for Claude Desktop) — default, opens no network ports
python -m bag_epl_mcp.server

# Streamable HTTP (cloud) — transport selected via env var
MCP_TRANSPORT=streamable-http MCP_HOST=0.0.0.0 MCP_PORT=8000 \
  pip install -e ".[http]" && python -m bag_epl_mcp.server
```

> **Transport & host are configured exclusively via environment variables**
> (`MCP_TRANSPORT`, `MCP_HOST`, `MCP_PORT`). The default is `stdio` bound to
> nothing; `MCP_HOST` defaults to `127.0.0.1` and should only be set to
> `0.0.0.0` inside a container/cloud environment.

Try it immediately in Claude Desktop:

> *"Is Methylphenidate (Ritalin) covered by mandatory health insurance?"*
> *"Which laws regulate admission to the Spezialitaetenliste?"*
> *"Is a wheelchair covered by mandatory insurance?"*

---

## Configuration

### Claude Desktop

Edit `~/Library/Application Support/Claude/claude_desktop_config.json` (macOS) or `%APPDATA%\Claude\claude_desktop_config.json` (Windows):

```json
{
  "mcpServers": {
    "bag-epl": {
      "command": "python",
      "args": ["-m", "bag_epl_mcp.server"]
    }
  }
}
```

Or with `uvx`:

```json
{
  "mcpServers": {
    "bag-epl": {
      "command": "uvx",
      "args": ["bag-epl-mcp"]
    }
  }
}
```

### Cloud Deployment (Streamable HTTP for browser access)

**Render.com (recommended):**
1. Push/fork the repository to GitHub
2. On [render.com](https://render.com): New Web Service → connect GitHub repo
3. Build command: `pip install -e ".[http]"`
4. Set the following environment variables:
   - `MCP_TRANSPORT=streamable-http`
   - `MCP_HOST=0.0.0.0` (required so the container accepts external traffic)
   - `MCP_PORT=8000` (or Render's `$PORT`)
   - *(optional)* `MCP_CORS_ORIGINS='["https://claude.ai"]'` to extend the
     browser CORS allow-list
   - *(optional)* OpenTelemetry tracing is **on by default** but a no-op unless
     the tracing deps are installed — build with `pip install -e ".[http,otel]"`
     and point `OTEL_EXPORTER_OTLP_ENDPOINT` at your collector. Set
     `MCP_OTEL_ENABLED=0` to disable.
5. Start command: `python -m bag_epl_mcp.server`
6. In claude.ai under Settings → MCP Servers, add: `https://your-app.onrender.com/mcp`

> **Security note:** the server exposes only public, read-only data and uses no
> authentication. See [`docs/SECURITY.md`](docs/SECURITY.md) for the threat
> model (egress allow-list, host binding, Lethal-Trifecta assessment).

---

## Available Tools

| Tool | Description |
|------|-------------|
| `epl_sl_suche` | Search the Spezialitaetenliste for compulsory-insurance medications |
| `epl_ggsl_abfrage` | Check GGSL coverage for congenital disorders |
| `epl_migel_suche` | Search the MiGeL for medical devices & aids |
| `epl_gesuchseingaenge` | List pending SL admission requests (transparency) |
| `epl_rechtskontext` | Legal context for coverage questions (WZW criteria) |
| `epl_server_info` | Server status and API phase information |

### Example Use Cases

| Query | Tool |
|-------|------|
| *"Is Ritalin covered by insurance?"* | `epl_sl_suche` |
| *"Which medications for congenital disorder GG-313?"* | `epl_ggsl_abfrage` |
| *"Is a wheelchair covered?"* | `epl_migel_suche` |
| *"Which laws regulate the SL?"* | `epl_rechtskontext` |

---

## Architecture

**Data flow (Phase 1):**

```
                         bag-epl-mcp (FastMCP)
 ┌────────────┐   MCP   ┌───────────────────────────────┐   HTTPS GET  ┌──────────────────┐
 │ MCP Client │◀───────▶│  tools (read-only)            │─────────────▶│ sl.bag.admin.ch  │
 │ (Claude    │ stdio / │   ├─ epl_sl_suche             │  egress      │ www.bag.admin.ch │
 │  Desktop,  │ Stream- │   ├─ epl_ggsl_abfrage         │  allow-list  │ www.fedlex...    │
 │  claude.ai)│ able    │   ├─ epl_migel_suche          │◀─────────────│ (public OGD)     │
 │            │ HTTP    │   ├─ epl_gesuchseingaenge     │  (no auth)   └──────────────────┘
 │            │         │   ├─ epl_rechtskontext        │
 │            │         │   └─ epl_server_info          │   structured JSON logs → stderr
 └────────────┘         │  resources: epl://uebersicht …│
                        │  prompts:   epl_kassenpflicht…│
                        └───────────────────────────────┘
```

**Phase roadmap** (details in [`docs/ROADMAP.md`](docs/ROADMAP.md)):

```
Phase 1 (current)  → legal context + entry points, no data retrieval
Phase 2 (planned)  → FHIR/IDMP API, once publicly accessible
Phase 3 (vision)   → MiGeL + AL via ePL-FHIR
```

**What Phase 1 does, and what it does not.** Five of the six tools make no
network request at all — there is exactly one outgoing HTTP call in the whole
module. They return the legal basis and an entry point, and they now say so.
The previous wording, "XML/XLSX downloads + SL website access", advertised a
capability with no code path behind it; on 2026-08-08 it was removed rather
than implemented, because the underlying source is not machine-readable.

That one HTTP call goes to `sl.bag.admin.ch/api/search` and receives **HTTP 200
with `text/html`** — the 51 KB Angular shell. A freely invented path under the
same prefix returns the identical response, byte for byte: there is no API at
that address. Previously the resulting JSON parse error was caught by a bare
`except Exception` and turned into the claim "the SL database API is not
publicly documented" — a statement about the BAG's publishing practice,
derived from a parser error. The tool now reports what was measured.

The SL front end calls `https://epl.bag.admin.ch/api/sl/` instead, on a
different host. That host answers 401 without authentication — but it answers
401 for invented paths too, so this does **not** establish that any particular
route exists. It is deliberately **not** on the egress allow-list: without
verifiable access, adding it would be a grant on suspicion.

**MCP protocol version:** `2026-07-28` natively, `2025-11-25` as the
`initialize` handshake ceiling. `epl_server_info` reports the revision the
calling connection actually negotiated — derived from the request, not written
down here a second time. See [MCP Protocol Version](#mcp-protocol-version) for
both eras. SDK
updates are proposed monthly via Dependabot; the protocol version is reviewed on
every `mcp` SDK bump — see the versioning policy in [`docs/ROADMAP.md`](docs/ROADMAP.md).

---

## Safety & Limits

- **Read-only:** All tools perform HTTP GET requests only — no data is written, modified, or deleted.
- **No personal data:** The server accesses public regulatory lists (SL, GGSL, MiGeL). No personally identifiable information (PII) is processed or stored.
- **No medical advice:** This server provides informational access to regulatory data only. For medical or legal decisions, always consult the official BAG sources and qualified professionals.
- **Rate limits:** The SL website (sl.bag.admin.ch) is a public Angular SPA; the server enforces a 30s timeout per request. Use `limit` parameters conservatively.
- **Data freshness:** Phase 1 tools link to live BAG sources. No caching is performed by this server.
- **Links are measured, not assumed:** the addresses handed out as "official source" are re-checked by `scripts/record_fixtures.py` on every run, together with a control request to an invented path. Two BAG pages previously handed out (`.../Arzneimittel/geburtsgebrechen-spezialitaetenliste.html` and `.../Arzneimittel/gesuchseingaenge.html`) answered HTTP 404 on 2026-08-08 and were replaced by the entry point that verifiably resolves — not by a guessed replaceme