MeuralMCP

Small LAN-first daemon, REST API, and MCP server for keeping Meural Canvas previews loaded.

Features

• Quiet daemon loop that retries often-failing frames without noisy logs.

• REST API protected by a shared token.

• MCP tools for coding agents to inspect devices and set the current image.

• Per-device current image storage.

• Orientation validation before writing a preview.

• In-memory/status tracking for LAN reachability failures.

• Optional cloud init that creates/assigns one-item blank galleries for landscape and portrait devices, sets hold durations, and syncs configured cloud device IDs.

Related MCP server: Home Assistant MCP

Credits

This project builds on public Meural local-control work from the community:

• Guy Sie's HA-meural, introduced on the Home Assistant forum, demonstrated that Meural Canvas devices expose both a cloud API and a local interface suitable for Home Assistant control.

• NETGEAR's support article documents the built-in browser-accessible /remote controller on the same LAN.

• bigboxer23/meural-control documented the practical issue with transient preview/postcard display and the more reliable single-playlist/gallery pattern.

Quick Start

Most users should run cloud init first. It is the step that discovers your frames, writes the starter config, changes Meural cloud timeout settings, and assigns the neutral blank gallery used by the local preview manager.

Cloud init changes these Meural cloud values:

• Sets imageDuration=86400, previewDuration=86400, and overlayDuration=120 on discovered devices.

• Finds or creates one landscape and/or one portrait blank gallery.

• Uploads one blank image to each blank gallery if the gallery is empty.

• Assigns each device to the matching blank gallery for its orientation.

• Syncs the devices after changing these settings.

Cloud init does not delete your existing Meural images or galleries, but it can change which gallery is assigned to each discovered device. Review the generated config.json after init and edit device names, IPs, orientations, or enabled flags before starting the daemon.

python -m venv .venv
. .venv/bin/activate
pip install -e .

meural-mcp --storage-dir ~/.config/meural-mcp init-cloud \
  --username "$MEURAL_USERNAME" \
  --password "$MEURAL_PASSWORD"

Package dependencies are declared in pyproject.toml; pip install -e . installs the CLI plus bounded runtime dependencies for FastAPI, Uvicorn, Requests, and MCP.

llms.txt is included as a concise map for coding agents and documentation ingestion. AGENTS.md contains contributor guardrails for keeping this repo public-safe.

If you do not want cloud init, init-local can create an empty generic config:

meural-mcp --storage-dir ~/.config/meural-mcp init-local --api-token "change-me"

With init-local, you must manually fill in device names, cloud IDs, LAN IPs, orientations, and enabled flags in ~/.config/meural-mcp/config.json. It also does not set timeout values or blank galleries in Meural cloud.

Run the API:

meural-mcp --storage-dir ~/.config/meural-mcp serve --host 127.0.0.1 --port 8733

Keep the REST API bound to localhost where possible. If you want to expose it to other machines, put nginx or Caddy in front of it and terminate HTTPS there rather than binding the API directly to the LAN as plain HTTP.

Check summary status:

curl http://127.0.0.1:8733/status \
  -H "Authorization: Bearer change-me"

Run the daemon:

meural-mcp --storage-dir ~/.config/meural-mcp daemon

Services and HTTPS

Sample service and reverse-proxy files are provided in examples/:

• examples/systemd/meural-mcp-daemon.service

• examples/systemd/meural-mcp-api.service

• examples/systemd/meural-mcp-user.service

• examples/systemd/meural-mcp-api-user.service

• examples/reverse-proxy/Caddyfile

• examples/reverse-proxy/nginx.conf

init-cloud is a one-shot CLI setup command. Run it manually so you can see and approve the cloud changes. The daemon and API are separate long-running processes: the daemon keeps previews loaded, and the API serves local status and image writes. In the system service examples, both long-running services use /var/lib/meural-mcp for config/state and expect the project installed at /opt/meural-mcp/.venv/bin/meural-mcp.

For a system install:

sudo useradd --system --home /var/lib/meural-mcp --create-home --shell /usr/sbin/nologin meural-mcp
sudo install -d -o meural-mcp -g meural-mcp /var/lib/meural-mcp
sudo cp examples/systemd/meural-mcp-*.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable --now meural-mcp-daemon.service meural-mcp-api.service

For a user install:

mkdir -p ~/.config/systemd/user
cp examples/systemd/meural-mcp-user.service ~/.config/systemd/user/meural-mcp.service
cp examples/systemd/meural-mcp-api-user.service ~/.config/systemd/user/meural-mcp-api.service
systemctl --user daemon-reload
systemctl --user enable --now meural-mcp.service meural-mcp-api.service

The user service samples expect meural-mcp at ~/.local/bin/meural-mcp. Adjust ExecStart if you installed into a project virtual environment instead.

For LAN access, keep meural-mcp-api.service on 127.0.0.1:8733 and expose it through HTTPS with Caddy or nginx. The shared token is still required by MeuralMCP, but TLS should protect the token in transit.

Run the MCP server for a coding agent:

meural-mcp --storage-dir ~/.config/meural-mcp mcp --transport stdio

If the MCP server runs on your workstation while the daemon/API run on another host, point it at the remote API instead. In this mode, set_device_image reads the image path from the workstation and uploads the bytes to MeuralMCP:

export MEURAL_MCP_API_URL="https://homepi:9443"
export MEURAL_MCP_API_TOKEN="..."
export MEURAL_MCP_API_VERIFY_TLS=false  # only for self-signed lab certs
meural-mcp mcp --transport stdio

MCP tools include:

• list_devices

• get_device_status

• get_device_image

• set_device_image

set_device_image stores the image only after validating orientation and successfully loading the preview to the device. It returns a failed result if the image cannot be parsed/thumbnailed, the orientation is wrong, the device is unknown, the file is missing, or the preview write fails.

Upload an image:

curl -X PUT http://127.0.0.1:8733/devices/canvas-1/image \
  -H "Authorization: Bearer change-me" \
  -H "Content-Type: image/jpeg" \
  --data-binary @image.jpg

Cloud Init Details

Cloud init requires a Meural username/password.

meural-mcp --storage-dir ~/.config/meural-mcp init-cloud \
  --username "$MEURAL_USERNAME" \
  --password "$MEURAL_PASSWORD"

On a Linux host with user systemd available, add --install-systemd to write, enable, and start meural-mcp.service. Interactive runs prompt for this unless --no-systemd-prompt is supplied.

init-cloud:

1. Authenticates to Meural cloud with the supplied username/password.

2. Discovers cloud device IDs, names, LAN IPs, and writes them to config.json.

3. Generates a shared API token, writes it to config.json, and prints it so you can save it for REST/MCP clients.

4. If config.json already exists, writes a timestamped backup first.

5. Finds or creates landscape and/or portrait blank galleries, depending on the discovered devices.

6. Ensures each blank gallery has a single correctly oriented blank image if the gallery is empty.

7. Assigns each configured device to the matching blank gallery for its orientation.

8. Sets imageDuration=86400, previewDuration=86400, overlayDuration=120.

9. Syncs configured devices.

After init, review and edit config.json if you need to adjust device names, cloud IDs, LAN IPs, orientations, or enabled flags before running the daemon.

FAQ

Why does this poll the devices?

Polling is not elegant, but it is deliberate. Meural frames can lose the loaded preview after sleep, boot, or other internal resets, so the daemon checks periodically and reloads the assigned preview when needed.

Why does setup use a blank image/gallery?

The blank image is a holding pattern. It keeps the device on a single neutral gallery by default, which makes the transition to locally managed previews a little less awkward than leaving whatever cloud playlist happened to be active.

Can I block the frames from the internet after setup?

Probably, but this still needs testing. Once cloud init has discovered devices, set the timeout values, and assigned the blank galleries, users may be able to firewall the Meural devices from the internet so future Meural cloud changes cannot alter or disturb them.

What would make this better?

A better solution likely needs hardware-level investigation. A community teardown/hacking post describes a Meural RK3288 board and locating G, R, and T test pads for ground, RX, and TX serial console access. Someone needs to open a device, attach to those serial pins, and see whether there is a cleaner local-control path than periodic preview reloads.