io.github.matematicsolutions/nl-eli-mcp
MCP server for Dutch consolidated legislation (BWB via KOOP SRU) with verifiable citations.
Open source Open in the app JSON README (API)
About
MCP server for Dutch consolidated legislation (BWB via KOOP SRU) with verifiable citations.
Details
- Kind
- MCP servers
- Topic
- Government & public data
- Publisher
- matematicsolutions
- Origin
- official
- Category
- ferramentas
- Transport
- local
- Version
- 0.4.3
- Stars
- 1
- Forks
- 2
- Last push
- 2026-08-24T13:57:23Z
- Repository state
- ativo
- Language
- Python
- License
- Apache-2.0
- Added
- 2026-08-29 04:00:29
- Updated
- 2026-08-29 04:00:29
- Origin id
io.github.matematicsolutions/nl-eli-mcp
README
# nl-eli-mcp
<!-- mcp-name: io.github.matematicsolutions/nl-eli-mcp -->
## Install (one command)
Published on PyPI + MCP Registry (`io.github.matematicsolutions/nl-eli-mcp`). Run without cloning:
```bash
uvx nl-eli-mcp
```
Configure your MCP client (stdio):
```json
{ "mcpServers": { "nl-eli-mcp": { "command": "uvx", "args": ["nl-eli-mcp"] } } }
```
### Windows 11 with Smart App Control
Smart App Control blocks unsigned executables, which covers `uvx.exe`, `pip.exe`
and the `nl-eli-mcp.exe` launcher that pip writes at install time. The `python.exe` and
`py.exe` from the python.org installer are signed by the Python Software
Foundation, so running the module through the interpreter works:
```bash
python -m pip install nl-eli-mcp
python -m nl_eli_mcp
```
`pip.exe` is blocked for the same reason, so install with `python -m pip`, not
`pip install`. If `python` is not on PATH, use the Windows launcher: `py -3 -m nl_eli_mcp`.
```json
{ "mcpServers": { "nl-eli-mcp": { "command": "python", "args": ["-m", "nl_eli_mcp"] } } }
```
Do not turn Smart App Control off to work around this - it cannot be re-enabled
without reinstalling Windows.
Building from source: see [Install](#install).
An MCP server for the **Dutch consolidated legislation BWB** (Basiswettenbestand), served by
KOOP over the official SRU API (`zoekservice.overheid.nl`, keyless). It gives an AI agent the
version of an act **in force on a given date**, with a verifiable citation: a persistent
identifier, a human-readable citation, and a link to the official source.
Part of the **eu-legal-mcp** line by [MateMatic](https://matematic.co) — one connector per EU
member state, the same citation contract everywhere.
> **On ELI.** The Netherlands does **not** publish native ELI (`/eli/`) URIs on consolidated
> BWB. To keep the line's contract honest, `eli_uri` carries the official persistent
> identifier instead — the `wetten.overheid.nl/id` *toestand* URI
> (e.g. `http://wetten.overheid.nl/id/BWBR0005537/2026-06-04/0`). The connector never
> fabricates an `/eli/` URI and says so in its tool instructions. See `DISCOVERY.md`.
## Tools
| Tool | What it does |
|---|---|
| `nl_search(query, on_date=today)` | Find acts by words in the title that are in force on a date. Returns distinct acts, each with the citation contract. |
| `nl_get_act(bwb_id, on_date=today)` | Metadata for one act (e.g. `BWBR0005537`) — identifier, title, authority, version date. |
| `nl_get_text(bwb_id, on_date=today)` | The full consolidated XML (BWB *toestand*) of one act. |
| `nl_case_search(date_from, date_to, ...)` | List court decisions (Rechtspraak Open Data) by date range / court / subject. No free-text; each hit carries a native `ecli`. |
| `nl_get_decision(ecli)` | A court decision by its ECLI (e.g. `ECLI:NL:HR:2020:1`) — court, dates, zaaknummer and full text. |
| `nl_coverage()` | Declare what this connector covers, when each family was captured, and - explicitly - what it does NOT cover. Every gap carries a fallback. |
Legislation comes from the **BWB** (KOOP SRU); case law comes from **Rechtspraak Open Data**
(`data.rechtspraak.nl`), keyed by native ECLI. Every response carries the **citation contract**:
- `eli_uri` — the official persistent identifier (toestand URI; see the ELI note above).
- `human_readable_citation` — the official short title (citeertitel), e.g. *Algemene wet bestuursrecht*.
- `source_url` — the browsable `wetten.overheid.nl` page for that version.
### Versions and dates
Each act has many time-stamped versions. The tools default to the version **in force today**;
pass `on_date` (`YYYY-MM-DD`) to pin a historical or future version. An act with no version
valid on that date returns `not_found` — retry with another `on_date`.
## Install
```bash
pip install -e ".[dev]"
```
Register it with your MCP client (see `.mcp.json.example`):
```json
{
"mcpServers": {
"nl-eli-mcp": {
"command": "nl-eli-mcp",
"env": {
"NL_ELI_BASE_URL": "https://zoekservice.overheid.nl/sru/Search",
"NL_ELI_CACHE_DIR": "~/.matematic/cache/nl-eli",
"NL_ELI_AUDIT_DIR": "~/.matematic/audit"
}
}
}
}
```
## Design
- **Public data only.** Read-only against the keyless KOOP SRU API and the official repository
host; nothing is sent beyond the query / identifier and the date.
- **Audit log.** Every call appends one JSON line to `~/.matematic/audit/nl-eli-mcp.jsonl`
(AI Act art. 12 record-keeping).
- **Vendor-neutral.** No LLM provider, no telemetry; own backoff + on-disk cache.
- **No fabrication.** Identifiers and titles are parsed from the source record. If KOOP's
schema changes, the connector fails loudly rather than returning stale or invented data.
See `CONSTITUTION.md` (the 4 principles) and `DISCOVERY.md` (how the source was mapped).
## Tests
```bash
pytest tests/test_instructions_drift.py tests/test_parse.py # offline
pytest tests/test_smoke.py # live KOOP API
```
## Licence
Apache-2.0. The Dutch legislation served is official public data of the Kingdom of the
Netherlands; this connector adds no rights over it.