Give a client a delivery-route calculation

Calculate a proposed visit order through a real MCP tool call, without a simulated assistant answer.

Expected result and prerequisites

The supplied stops produce warehouse → library → cafe → museum → warehouse and 12 estimated minutes. This educational example uses fictional coordinates and Manhattan distance as minutes. It is distinct from the recorded Paris demonstration, with no live traffic, optimum guarantee or universal savings claim.

Use Python 3.11–3.14, Apizr core and a separate MCP runtime. Download logistics-tool.zip, extract outside the checkout and open logistics-tool/. Files are route.py, stops.json and real client.py; data/algorithm are pedagogical GPL-3.0-or-later. No external routing service, analysis plugin or paid account is used.

Choose one public tool

export ROUTE_BUNDLE="$(cd .. && pwd -P)/route-bundle"
apizr inspect route.py
apizr generate mcp route.py --select plan_route --output-dir "$ROUTE_BUNDLE"

_minutes stays private. plan_route uses nearest-neighbour selection with a lexical tie-break. Apizr supplies the adapter, not the algorithm or a model decision.

Call the generated calculation

Starting the server executes trusted source; the client owns its stdio process.

python -m venv ../route-runtime
../route-runtime/bin/python -m pip install -r ../route-bundle/requirements.txt
../route-runtime/bin/python client.py ../route-runtime/bin/python ../route-bundle/server.py

The official MCP client initializes, lists only plan_route, calls {"stops":["museum","cafe","library"]} and asserts:

{"ok":true,"route":["warehouse","library","cafe","museum","warehouse"],"estimated_minutes":12}

An assistant may optionally choose this tool and its arguments; the essential calculation runs without one. No simulated model response is involved.

Useful failure, limits and cleanup

The client also calls {"stops":["unknown"]} and checks {"ok":false,"reason":"unknown_stop"}. Supply known unique stops to correct it. Duplicate/empty lists have another business refusal; non-string members are MCP contract errors. The greedy algorithm need not find an optimum, fictional minutes are not measurements, and vehicle constraints are absent. The context stops its server. Remove only the extracted project, route-bundle/ and route-runtime/.