Environment Variables

Overview link

MCP Explorer is configured entirely via environment variables — there are no required config files to edit. Copy .env.example to .env, fill in your values, and pass it to Docker or Docker Compose.

  # Docker Compose (reads .env automatically)
cp .env.example .env
docker compose up -d

# docker run (pass vars individually)
docker run -p 8090:8080 \
  -e MCP_CLIENT_NAME=my-app \
  -e MCP_DATA_PATH=/data \
  -v /path/to/data:/data \
  ghcr.io/your-org/mcp-explorer:latest
  

info: In Docker Compose, variables in .env are interpolated into docker-compose.yml automatically. Variables prefixed VITE_ are build-time only — they are baked into the static JS bundle and cannot be changed at runtime.

API Container Variables link

These apply to the api service (Garrard.Mcp.Explorer.Api).

ASP.NET Core link

App Metadata link

MCP Client link

Preferences / Storage link

Default data directory locations on the host (for MCP_DATA_PATH):

Dev Tunnels link

HOST_DEVTUNNELS_DIR lets the container inherit your host machine’s existing devtunnel user login session, so you never have to go through the device-code flow inside Docker.

Per-OS values for HOST_DEVTUNNELS_DIR:

tip: If you have never run devtunnel user login on your host, leave this empty and complete the one-time device-code login from the Device Code Login dialog in MCP Explorer. Credentials are written to the devtunnels-cli named volume and will survive docker compose down (but not docker compose down -v).

Azure Integration link

MCP Explorer can use Azure Key Vault secrets and Entra App Registrations to populate connection credentials. The API container uses DefaultAzureCredential (Azure CLI → environment → managed identity) to authenticate with Azure.

Per-OS values for HOST_AZURE_CONFIG_DIR:

tip: The volume is mounted read-write (not read-only) because the Azure CLI refreshes expired access tokens by writing back to msal_token_cache.json. A read-only mount silently blocks token refresh and causes authentication failures.

LLM Service link

Tool Invocation link

Elicitation link

Gateway / Frontend Container Variables link

These apply to the frontend service (Garrard.Mcp.Explorer.Gateway) and control how the gateway routes traffic and what port is exposed.

Port Mapping link

YARP Reverse Proxy link

Frontend Build-Time Variables (VITE_*) link

warning: These variables are baked into the static JS bundle at build time. They cannot be changed after the image is built. If you need different values, rebuild the image.

Read-Only / Implicit Variables link

These are set automatically by the .NET runtime or Docker base images and are documented here for completeness.

Quick Reference link

  # Minimal docker run (single container)
docker run -p 8090:8080 \
  -v mcp-data:/data \
  ghcr.io/your-org/mcp-explorer:latest

# With custom client name and existing settings
docker run -p 8090:8080 \
  -e MCP_CLIENT_NAME=my-team \
  -e MCP_DATA_PATH=/Users/me/Library/Application\ Support/McpExplorer \
  -v "/Users/me/Library/Application Support/McpExplorer":/data \
  ghcr.io/your-org/mcp-explorer:latest

# docker compose — copy .env.example to .env, edit, then:
docker compose up -d
  

Azure Integration Quick Reference link

  # .env — enable Azure Key Vault & App Registration browsing in Docker
HOST_AZURE_CONFIG_DIR=~/.azure          # macOS / Linux
# HOST_AZURE_CONFIG_DIR=%USERPROFILE%\.azure  # Windows

# AZURE_CONFIG_DIR is set automatically inside the container
# Do NOT put AZURE_CONFIG_DIR in your .env
  

Then run:

  docker compose up --build
  

MCP Explorer will pick up your az login session and show “Connected” in the Azure Context Banner on the Connections page.

Dev Tunnels Quick Reference link

  # .env — reuse your host devtunnel login inside Docker
# macOS:
HOST_DEVTUNNELS_DIR=/Users/<you>/Library/Application\ Support/DevTunnels
# Linux:
# HOST_DEVTUNNELS_DIR=/home/<you>/.devtunnels
# Windows:
# HOST_DEVTUNNELS_DIR=C:\Users\<you>\AppData\Local\DevTunnels
  

Then run:

  docker compose up -d
  

MCP Explorer will inherit your host devtunnel user login session and start tunnels without prompting for device-code authentication.