How to configure the Ozeki SMS MCP Server in LibreChat

This guide walks you through integrating the Ozeki SMS MCP Server with LibreChat, an open-source chat application that supports MCP servers through its built-in MCP configuration system. By following this tutorial, you will learn how to whitelist your gateway domain in the LibreChat configuration file, restart the Docker container, and register the Ozeki SMS Gateway as an MCP server.

What is an MCP server?

An MCP (Model Context Protocol) server exposes tools that an AI model can call during a conversation. In this setup, the Ozeki SMS MCP Server provides SMS tools such as sending messages and listing incoming SMS. LibreChat connects to the MCP server over HTTP using the Streamable HTTP transport and authenticates using the API key you generated for your MCP user account.

LibreChat
LibreChat SMS MCP Server Overview

LibreChat MCP server configuration

# Add the gateway address to the allowed domains in librechat.yaml 
mcpSettings:
  allowedDomains:
    - "{address}"
    # For example: - "192.168.88.15"

# Restart the Docker container to apply changes
docker compose down
docker compose up -d

# Open LibreChat in your browser
http://localhost:3080/

# Add the MCP server with the following details:
Name: Ozeki
MCP Server URL: http://{address}:9529/mcp
Transport: Streamable HTTP
Authentication: API Key

Steps to follow

We assume Ozeki SMS Gateway is already installed on your system and you have already created an MCP user account with an API key. You will also need LibreChat installed on your system. If you have not set it up yet, follow our LibreChat setup guide.

  1. Add the gateway address to the allowed domains
  2. Restart the Docker container
  3. Add the Ozeki SMS MCP Server
  4. Connect to the MCP server

Video tutorial

The following video shows how to add the Ozeki SMS MCP Server to LibreChat step-by-step.

Step 1 - Add the gateway address to the allowed domains

Open the librechat.yaml configuration file in a text editor. This file controls LibreChat's behavior, including which external domains are permitted to be used as MCP server endpoints (Figure 1).

Open librechat.yaml config file
Figure 1 - Open the librechat.yaml configuration file

Locate the mcpSettings section in the file and add your Ozeki SMS Gateway's IP address or hostname under allowedDomains as shown below (Figure 2). 

mcpSettings:
  allowedDomains:
    - "{address}"

Locate and add Ozeki SMS MCP to allowed domains
Figure 2 - Add the Ozeki SMS Gateway address to the allowed domains

Save the configuration file and close the text editor. The change will not take effect until the Docker container is restarted in the next step (Figure 3).

Save config file and close text editor
Figure 3 - Save the configuration file and close the text editor

Step 2 - Restart the Docker container

Open a terminal window in your LibreChat folder. On Windows you can do this by selecting Open in Terminal from the right-click context menu (Figure 4).

Open LibreChat folder in terminal
Figure 4 - Open a terminal in the LibreChat folder

Run the following commands to stop and restart the LibreChat Docker container. This reloads the updated librechat.yaml configuration (Figure 5). 

docker compose down
docker compose up -d

Compose the container
Figure 5 - Restart the LibreChat Docker container

Step 3 - Add the Ozeki SMS MCP Server

Open LibreChat in your browser at http://localhost:3080/ and log in. Navigate to the MCP Servers section in the interface and click Add to open the MCP server registration window (Figure 6).

Navigate to MCP Servers in LibreChat and press Add
Figure 6 - Navigate to MCP Servers and click Add

Enter Ozeki as the server name and enter the URL of your Ozeki SMS Gateway in the MCP Server URL field following the format http://{address}:9529/mcp. Make sure Streamable HTTP is selected as the transport type (Figure 7).

Enter MCP server name and URL
Figure 7 - Enter the MCP server name and URL

Set the Authentication type to API Key -> Bearer and paste the API key you generated for your MCP user account into the token field. Check the I trust this application checkbox, then press Create to save the MCP server entry (Figure 8).

Select API key auth, paste token and create connection
Figure 8 - Select API Key authentication, paste your token and click Create

Connect to the MCP server

The Ozeki MCP server will now appear in the MCP server list. Click the Connect button next to it to establish the connection. Once connected, the SMS tools exposed by the gateway will be available to the AI model in LibreChat conversations (Figure 9).

Press Connect next to the server in the MCP list
Figure 9 - Click Connect next to the Ozeki server in the MCP list

Summary

You have successfully configured the Ozeki SMS MCP Server in LibreChat. The AI model running in LibreChat can now send and receive SMS messages through your gateway using plain language prompts, making it straightforward to add mobile messaging capabilities to any LibreChat workflow.

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