diet_guard

A log-to-unlock gate: locks the desktop until a meal is logged once a meal slot (08:00 / 12:00 / 16:00 / 20:00) has elapsed without one, and tracks a sealed daily calorie/macro budget.

Install

bash install.sh

This installs the package + dependencies into system Python's user site-packages (the systemd service runs /usr/bin/python directly, not a venv — see CLAUDE.md), installs the systemd user timer, seals your daily budget, and locks the budget file immutable.

Usage

python -m diet_guard init          # one-time: compute and seal today's budget
python -m diet_guard gate --demo   # test the lock window (safe, closeable)
python -m diet_guard averages      # weekly/monthly average kcal vs budget

Averages

averages prints the mean kcal/day for this week, last week, this month and last month, each labelled under / slightly over / very over.

Three rules make the number honest, and all three are mirrored in the phone app and the gate's History tab:

• the mean is over logged days only -- a day you forgot to log is not a zero-calorie day, and averaging it in as one would make every gap in the log read as "well under budget";
• the yardstick is the mean of the budgets that applied on those same days, not today's budget, so editing the budget never retroactively reclassifies a past week (same reason the calendar uses .budget_history);
• today is excluded -- every period ends at yesterday, because a half-logged today drags the mean far enough to flip the band. On a Monday "this week" therefore reports no logged days yet rather than a flattering number.

The band boundaries are the calendar's own (at or under budget / up to 20% over / more than 20% over), so a period and its day cells can never disagree about what "over" means.

The timer runs the gate automatically every ~30 minutes; no manual invocation is needed once installed.

MCP server

An optional Model Context Protocol server lets an MCP client (Claude Code and its subagents) query today's intake and log meals as typed tools instead of shelling out to the CLI. It runs in its own venv (~/.venvs/diet-guard-mcp) so the mcp SDK never touches the dependency-light system/CLI python path.

Tools:

• get_status — today's consumed kcal + macros, the consumption band (on track / approaching limit / OVER BUDGET, or none when no budget is sealed), plus due / logged / current meal slots.
• list_today — today's logged meals (description, kcal, macros, source, slot).
• get_slots — the day's fixed meal slots and the current one.
• get_averages — average kcal/day for this/last week and this/last month, each with its band (under / slightly_over / very_over). Returns the intake and the band only — never the period's average budget.
• log_meal(description, grams=, kcal=, protein=, carbs=, fat=, slot=, confirm=False) — gated write: with confirm=False it previews the resolved nutrition and target slot and mutates nothing; only confirm=True appends the entry. The gate is intrinsic — never add this tool to a permission allowlist, since a client's auto-approve mode would otherwise bypass the human confirmation.

The read tools deliberately never expose the raw daily budget number (only the qualitative band), nor the sealed .budget file, the shared HMAC key, or the sync token — the budget stays hidden by design.

Setup:

bash scripts/setup_mcp.sh   # create the venv and install diet_guard[mcp]

Then restart Claude Code in this repo and approve the project MCP server (registered in .mcp.json).

Development

python -m venv .venv && .venv/bin/pip install -r requirements.txt
.venv/bin/pre-commit install && .venv/bin/pre-commit install --hook-type pre-push
.venv/bin/python -m pytest diet_guard/tests/ --cov=diet_guard --cov-branch --cov-fail-under=100

See CLAUDE.md for scheduling details and production deployment gotchas, and docs/design.md for the original feature spec.