Persistent Configuration

4 min

By default, configuration saved through the Web UI (API keys, Litmus Edge instances, model preferences, NATS / InfluxDB / LEM settings) is written to /app/.env inside the container. It is lost when the container is removed.

To retain configuration across container restarts and replacements, mount a host file over /app/.env.

One-time setup

mkdir -p /opt/litmus-mcp
touch /opt/litmus-mcp/.env

The host-side file must be created with touch before running the container. If it does not exist, Docker creates a directory at that path and the application fails to write configuration.

Run with the volume mount

docker run -d --name litmus-mcp-server \
  -p 8000:8000 -p 9000:9000 \
  -v /opt/litmus-mcp/.env:/app/.env \
  ghcr.io/litmusautomation/litmus-mcp-server:latest

Any configuration you save in the UI is written to /opt/litmus-mcp/.env on the host. A new container started with the same -v flag picks it up automatically on startup.

Docker Compose equivalent

services:
  litmus-mcp-server:
    image: ghcr.io/litmusautomation/litmus-mcp-server:latest
    ports:
      - "8000:8000"
      - "9000:9000"
    volumes:
      - /opt/litmus-mcp/.env:/app/.env

What gets persisted

The mounted .env ends up holding:

ANTHROPIC_API_KEY, OPENAI_API_KEY, GEMINI_API_KEY (whichever you set)

PREFERRED_MODEL, PREFERRED_MODEL_ID

ACTIVE_EDGE_INSTANCE, plus EDGE_INSTANCE_{i}_* entries for each registered Litmus Edge

Canonical EDGE_URL, EDGE_API_CLIENT_ID, EDGE_API_CLIENT_SECRET (mirror of the active instance)

NATS_SOURCE, NATS_PORT, NATS_USER, NATS_PASSWORD, NATS_TLS

INFLUX_HOST, INFLUX_PORT, INFLUX_DB_NAME, INFLUX_USERNAME, INFLUX_PASSWORD

LEM headers if configured

You can also seed the file before first start by writing values directly. The Web UI will read what is already there.