How to set up an SMS MCP server to receive SMS in Codex
This guide walks you through retrieving incoming SMS messages in Codex using the Ozeki SMS MCP server. By following this tutorial, you will learn how to verify the MCP server connection, instruct the AI agent to list incoming messages in plain language, and confirm the transaction through the gateway logs.
What is an MCP tool call?
An MCP (Model Context Protocol) tool call is how an AI model communicates with external systems. When the AI needs to retrieve data such as incoming SMS messages, it sends a structured request to the appropriate MCP server, which processes it and returns the result back to the model.
Example prompt
List all incoming SMS messages.
Steps to follow
We assume Ozeki SMS Gateway is already installed on your system, you have created an MCP user account with an API key, and you have already configured the Ozeki SMS MCP server in Codex.
Video tutorial
The following video shows how to retrieve incoming SMS messages in Codex using the Ozeki SMS MCP server step-by-step.
Step 1 - Verify the MCP server connection
Before retrieving messages, run the /mcp command in Codex to confirm
that the Ozeki MCP server is listed and its status shows as connected (Figure 1).
Step 2 - Use the list incoming messages tool
In the Codex prompt, type your request in plain language and press Enter. The AI agent will interpret the request and invoke the appropriate MCP tool to retrieve the messages from the gateway inbox (Figure 2).
List all incoming SMS messages.
Codex may ask for your approval before invoking the tool. Review the proposed tool call and confirm to allow the AI agent to proceed (Figure 3).
The result will appear in the Codex terminal, displaying the list of incoming messages. Each entry includes the sender number, message text, and timestamp confirming when it was received (Figure 4).
Step 3 - View the transaction in logs
Open Ozeki SMS Gateway in your browser and navigate to the MCP user details page by clicking on the MCP user entry in the Users and applications panel (Figure 5).
In the MCP user event log, you should see an entry for the incoming message retrieval request as well as the response, confirming that the API key authentication, tool call, and data retrieval were all processed correctly by the gateway (Figure 6).
Final thoughts
You have successfully retrieved incoming SMS messages in Codex using the Ozeki SMS MCP server. The AI agent running in Codex can now list incoming messages from your gateway simply by being asked to do so in plain language, making it easy to add SMS inbox access to any Codex workflow.