Pet Log MCP Server

A local MCP server for household pet care notes: vet-visit histories, medication organizers, weight trends, feeding notes, and on-demand groomer/sitter handoff summaries. Plain Python, standard library only, JSON-RPC over stdio — exactly what an MCP client expects. No network calls, ever.

Education and organizing only. This tool is a notebook, not a vet. It stores and summarizes your own notes; it never gives medical, medication dosing, or feeding advice. Always consult your veterinarian for medical decisions.

Made by Asdale Dynamics, LLC — plain-English AI education and practical local-first tools. Licensed MIT.

Why this exists

The companion project new-pet-first-week-guide is the setup manual for a pet's first days home. This project is the ongoing log: the place where the checkup records, medication schedules the vet gave you (organized by you, corrected by you), weigh-ins from your own scale, food notes, and hand-off notes for the groomer or pet sitter live for the long haul.

Related MCP server: notes-box

How it works

• One JSON folder you own. All data lives in six plain-JSON files (pets.json, vet_visits.json, medications.json, weights.json, feeding_notes.json, handoff_notes.json) in a single folder. Open it, read it, back it up, keep it in your own cloud drive if you like.

• MCP-style stdio server. Speaks JSON-RPC 2.0 (the same shape the Model Context Protocol uses) with initialize, notifications/initialized, ping, tools/list, and tools/call. One JSON message per line on stdin, one response per line on stdout; log messages go to stderr only.

• Zero dependencies at runtime. Python 3.10+ standard library only. pytest is a test-time dependency only.

Tools (13)

Quick start

Run the server directly (no install needed, from the repo folder):

python -m pet_log_mcp

Name the data folder explicitly (default is ./pet-log-data):

PET_LOG_DATA_DIR=/home/you/pet-logs python -m pet_log_mcp

Or install it with pip to get the pet-log-mcp command:

pip install .

Manual smoke test

printf '%s\n' \
  '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}' \
  '{"jsonrpc":"2.0","id":2,"method":"tools/list"}' \
  '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"add_pet","arguments":{"name":"Mochi","species":"cat"}}}' \
  | python -m pet_log_mcp

Wiring it into an MCP client

Point your MCP client at the process python -m pet_log_mcp (transport: stdio, no args). If the client app stores mcpServers config, a local-first example looks like:

{
  "mcpServers": {
    "pet-log": {
      "command": "python",
      "args": ["-m", "pet_log_mcp"]
    }
  }
}

Set PET_LOG_DATA_DIR in the environment (or add an "env" block, if your client supports it) to keep the JSON folder wherever you keep personal data.

Tests

python -m pytest

The test suite covers the store, every tool (through mocked/fake persistence), the full JSON-RPC protocol surface, and a subprocess end-to-end run of the real stdio server. No test touches the network.

Privacy, first and always

• Everything stays in the local JSON folder. Nothing is sent anywhere.

• No telemetry, no analytics, no embedded API keys, no commitments.

• Because it's your data: adding a pet's name in the log is on you; the file format is plain JSON so you can edit or export anytime.

Disclaimer

Pet Log MCP Server is an organizing and education tool. It does not provide veterinary diagnosis, treatment, dosing, or feeding recommendations and must not be used as a substitute for professional veterinary care.

License

MIT — see LICENSE. Copyright (c) 2026 Asdale Dynamics, LLC.