How to set up an SMS MCP server to send SMS from Claude Cowork
This guide walks you through sending an SMS message from Claude Cowork using the Ozeki SMS MCP server. By following this tutorial, you will learn how to instruct Claude to send an SMS in plain language, allow the tool use, and confirm that the message was delivered 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 perform an action such as sending an SMS, it sends a structured request to the appropriate MCP server, which processes it and returns the result back to the model.
Example prompt
Send an SMS to +36301234567, the message should be "Hello from Claude Cowork".
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 Claude Cowork.
Video tutorial
The following video shows how to send an SMS message from Claude Cowork using the Ozeki SMS MCP server step-by-step.
Step 1 - Use the Send SMS tool
Type a plain language instruction in the Claude Cowork chat prompt asking the AI to send an SMS to a specific phone number. Claude will interpret the request and call the appropriate MCP tool to deliver the message (Figure 1).
Send an SMS to +36301234567, the message should be "Hello from Claude Cowork".
Claude Cowork may prompt you to allow the tool use before proceeding. This is a security confirmation to ensure you are aware that an external tool is being called on your behalf. Confirm the action to allow Claude to send the SMS (Figure 2).
You will see the result of the Send SMS tool call in the chat window. A successful response confirms that the message has been passed to the gateway and queued for delivery (Figure 3).
Step 2 - Check the SMS in the SMS Gateway 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 4).
In the MCP user event log, you should see an entry for the outgoing message, including the recipient number and message text, confirming that it was successfully processed by the gateway (Figure 5).
Conclusion
You have successfully sent an SMS message from Claude Cowork using the Ozeki SMS MCP server. Claude can now deliver SMS messages to any phone number simply by being asked to do so in plain language, making it easy to add mobile messaging to any Claude Cowork workflow.