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I am running LibreChat using Docker Compose on an Ubuntu server. While checking the logs for the API container related to MCP servers, I consistently see UID/GID warnings and the MCP server does not seem to initialize beyond creating a new instance.

Command

docker compose logs -f api | grep MCP

Output

WARN[0000] The "UID" variable is not set. Defaulting to a blank string.
WARN[0000] The "GID" variable is not set. Defaulting to a blank string.
WARN[0000] The "UID" variable is not set. Defaulting to a blank string.
WARN[0000] The "GID" variable is not set. Defaulting to a blank string.
WARN[0000] The "UID" variable is not set. Defaulting to a blank string.
WARN[0000] The "GID" variable is not set. Defaulting to a blank string.
LibreChat  | 2026-01-15 12:40:21 info: [MCPServersRegistry] Creating new instance

Context

• OS: Ubuntu (cloud VM)

• LibreChat running via docker compose

• MCP server configured (ClickHouse MCP in my case)

• Containers start successfully, but MCP does not appear to fully initialize

• No explicit crash or fatal error is shown

What I have checked

• Docker and Docker Compose are installed correctly

• LibreChat containers are running

• MCP configuration exists in LibreChat config

• Issue appears even when only monitoring logs (no user interaction)

Questions

1. Are these UID / GID warnings harmless, or can they prevent MCP from initializing correctly?

2. Do I need to explicitly define UID and GID in:

   • .env file, or

   • docker-compose.yml?

3. Is the MCP server expected to log additional messages after Creating new instance, or does this indicate it is stuck?

4. What is the recommended way to configure UID/GID for LibreChat + MCP in Docker?

Any guidance or example configuration would be appreciated.