mtrview 0.4.2

Human-friendly dashboard for mtr2mqtt summary topics

mtrview

mtrview is a small standalone web dashboard for retained JSON summaries published by mtr2mqtt. mtr2mqtt writes the measurement summaries to MQTT; mtrview subscribes to those topics and turns the latest values into a simple human-friendly dashboard.

The app subscribes to summary topics such as summary/<receiver>, keeps the latest summary per receiver in memory, normalizes transmitter readings, and serves a dark auto-updating dashboard at http://localhost:8000/.

MQTT input

By default mtrview subscribes to:

summary/#

Each retained message should be a JSON object with a receiver, an updated_at timestamp, and a transmitters mapping. Transmitter metadata may be partial; missing location, zone, quantity, description, unit, or battery fields are displayed with sensible placeholders instead of failing.

Configuration

Settings are read from environment variables:

Variable	Default
MTRVIEW_MQTT_HOST	localhost
MTRVIEW_MQTT_PORT	1883
MTRVIEW_MQTT_USERNAME	unset
MTRVIEW_MQTT_PASSWORD	unset
MTRVIEW_MQTT_TOPICS	summary/#
MTRVIEW_HTTP_HOST	0.0.0.0
MTRVIEW_HTTP_PORT	8000
MTRVIEW_REFRESH_INTERVAL_SECONDS	20
MTRVIEW_DISPLAY_TIMEZONE	UTC
MTRVIEW_UPDATE_CHECK_ENABLED	true
MTRVIEW_UPDATE_CHECK_URL	GitHub latest release API
MTRVIEW_UPDATE_CHECK_INTERVAL_SECONDS	21600

See .env.example for a copyable starting point.

Local run

uv sync --group dev
uv run mtrview

Then open http://localhost:8000/.

Useful endpoints:

• GET / - dashboard
• GET /api/summary - normalized JSON for all receivers and transmitters
• GET /health - health status

Docker

docker build -t mtrview .
docker run --rm -p 8000:8000 \
  -e MTRVIEW_MQTT_HOST=host.docker.internal \
  -e MTRVIEW_MQTT_TOPICS=summary/# \
  mtrview

Published Docker images support linux/amd64, linux/arm64, linux/arm/v7, and linux/arm/v6 for Pi Zero-class 32-bit ARM devices. The image intentionally uses Uvicorn without optional native performance extras so old Raspberry Pi targets can install dependencies without a compiler and the runtime image stays small.

Dashboard

The UI is server-rendered first, with a small vanilla JavaScript refresh loop that fetches /api/summary. It includes summary counts, MQTT connection state, search, status/zone/receiver filters, card and compact table views, and a priority section for non-online readings. Transmitter battery state is shown in the card, table, and detail views when present. Battery labels are derived from voltage: full at 3.1 V or higher, good at 2.9-3.0 V, medium at 2.7-2.8 V, low at 2.6 V, and critical at 2.5 V or lower.

The dashboard footer shows the running mtrview version. By default the browser asks /api/version for update status, and the server checks the latest GitHub release with a six-hour cache. Set MTRVIEW_UPDATE_CHECK_ENABLED=false to disable outbound update checks, or set MTRVIEW_UPDATE_CHECK_URL to another compatible JSON endpoint that exposes tag_name or name.

Development

make install
make verify

Individual checks:

uv run pytest
uv run ruff check .

Releases

Releases are managed by GitHub Actions using Conventional Commits and semantic-release. Merges to master can create GitHub releases, publish the Python package to PyPI, and publish multi-arch Docker images to Docker Hub as tvallas/mtrview.