Turning four compliance and lead-cost checks into a local, read-only MCP server

We run a small call-centre outsourcing brokerage, and a few questions kept coming back to us. Is this telemarketing consent still valid under France's new one-year rule? Which lead source is actually cheapest once you count the meetings that took place, not the leads? What is missing in a GDPR set-up when customer service is outsourced outside the EU?

Over the last weeks we turned those questions into small, standard-library Python packages. This weekend we wrapped four of them in an MCP server, so that Claude, Cursor and other MCP clients can call them directly: kanibal-tools-mcp.

claude mcp add kanibal-tools -- uvx kanibal-tools-mcp

For Claude Desktop, Cursor or any other client, the configuration is the usual one:

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

The four tools

Each one wraps a package that is published on its own: demarchage-consent, cost-per-kept-meeting, rgpd-offshore-check and least-cost-capable.

Design choices

Local, read-only, closed-world. Every tool computes from its arguments only: no network call, no file access, no state kept between calls. The tools say so to the client through MCP annotations:

LOCAL_READ_ONLY = ToolAnnotations(
    readOnlyHint=True,
    destructiveHint=False,
    idempotentHint=True,
    openWorldHint=False,
)

Fail-closed. A missing or unreadable consent date is preuve_manquante, never valide. In the GDPR checklist, only a JSON true satisfies a check: an unanswered item is reported as "to verify" and still counts as blocking.

Bounded claims. The consent and GDPR tools are checklists, not legal advice. A low cost per kept meeting does not prove profitability. The model picker only uses the facts in the catalogue it receives; it does not call providers or promise savings.

Testing through a real MCP session

The tests do not call the Python functions directly. They go through an in-memory MCP client session, so they also check the tool names, schemas and annotations that a client sees:

from mcp.shared.memory import create_connected_server_and_client_session
from kanibal_tools_mcp.server import mcp

async def list_tools():
    async with create_connected_server_and_client_session(mcp._mcp_server) as client:
        return (await client.list_tools()).tools

One small surprise: FastMCP takes no version argument, so the server reported the SDK version (1.30.0) instead of its own. Setting it on the low-level server fixed it:

mcp._mcp_server.version = __version__

Publishing: PyPI, the MCP Registry, Glama

PyPI uses Trusted Publishing from a release.yml workflow. The publish job runs in a GitHub environment called pypi that requires a maintainer's approval and only accepts v* tags, so no token is stored anywhere.

The official MCP Registry lists the server as io.github.kanibal-studio/kanibal-tools-mcp. Two details mattered:

• The registry checks ownership of a PyPI package through an mcp-name: io.github.kanibal-studio/kanibal-tools-mcp line in the README that PyPI shows.
• The interactive mcp-publisher login github flow cannot currently publish under an organisation namespace. Publishing from GitHub Actions with mcp-publisher login github-oidc can, so the release workflow does it right after the PyPI job, and waits until PyPI serves the new version first.

Glama runs its own checks before listing a server. For a repository that belongs to an organisation, it first wants a glama.json at the root naming the maintainers. Its Dockerfile is generated from a small form. The first build failed: uv pip install --system . targeted Debian's Python, which is marked as externally managed. A dedicated virtual environment fixed it:

["uv venv /opt/venv --python 3.12", "uv pip install --python /opt/venv/bin/python ."]

with /opt/venv/bin/python -m kanibal_tools_mcp as the start command. Glama then started the server and listed its four tools.

Try it, and tell us what is missing

• Code: https://github.com/kanibal-studio/kanibal-tools-mcp (MIT)
• PyPI: https://pypi.org/project/kanibal-tools-mcp/
• Product Hunt: https://www.producthunt.com/products/kanibal-tools-mcp

We would like feedback on the tool interfaces, especially from people who run outbound or customer-service teams across EU borders.