SMS MCP server: send SMS from Claude and ChatGPT

MCP (Model Context Protocol) is the standard AI assistants use to call tools of other services. Once TopSMS is connected to Claude or ChatGPT, the assistant can send an SMS from your account, check whether it was delivered or tell you how much credit is left. No code, just plain sentences.

What the assistant can do

• send an SMS to one number, now or scheduled (up to 30 days ahead)
• send the same text to up to 500 numbers
• check the delivery status of a message or batch, and cancel a scheduled send (the credit is refunded)
• send a verification code (OTP) and check the code the user entered
• show your credit balance and the price list

Example prompts

• “Text +49 151 12345678: Hello, your order 1024 is ready for pickup.”
• “Tomorrow at 8:00, send these three numbers a reminder: Your appointment is tomorrow at 10:00.”
• “Has that message been delivered yet? If not, why?”
• “How much credit do I have, and what does an SMS to Austria cost?”
• “Send a verification code for the app Booking to +43 664 1234567.”

Connect in Claude

1. In Claude, open Settings → Connectors → Add custom connector.
2. Name: TopSMS, URL: https://topsms.eu/api/mcp. Leave OAuth Client ID and Client Secret empty.
3. Click Connect, sign in to your TopSMS account and click Allow on the consent screen.
4. In a chat, enable the TopSMS connector in the tools menu and say what you want to send.

If you do not see the custom connector option, it depends on your Claude plan or your organisation’s settings.

Connect in ChatGPT

1. In ChatGPT, open Settings → Apps & Connectors and turn on Developer mode in the advanced settings.
2. Create a connector: name TopSMS, URL https://topsms.eu/api/mcp, authentication OAuth.
3. Sign in to your TopSMS account and click Allow.
4. Select the TopSMS connector in a chat.

ChatGPT offers developer mode on some plans only, and OpenAI changes it regularly, so menu names may differ.

Claude Code, Cursor and other clients

In Claude Code, run this command, then type /mcp, pick topsms and sign in in the browser:

claude mcp add --transport http topsms https://topsms.eu/api/mcp

Clients without sign-in (such as Cursor) use the same URL with the header Authorization: Bearer CLIENT_ID:SECRET, or the npm package topsms-mcp. Configuration on the MCP server page.

Security

• You see the consent first. The consent screen shows which app is asking and what it may do: send SMS and spend credit, read your credit and message status. You type your password only on TopSMS; the assistant never sees it.
• A separate key. Each connection creates a key “OAuth: app name” with an OAUTH badge under API access in the dashboard, with its usage count and request log.
• Disconnect in one click. Revoke that key and the assistant loses access immediately.
• Same rules as an API key: same credit, same sender rules, same per-minute rate limit.
• Try it first. A test API key sends and charges nothing, yet responses look like live ones. Connect it with the header in Claude Code or Cursor. Sign-in connections in Claude and ChatGPT always use a live key.

What does it cost?

The MCP server and the connection are free. An SMS sent by the assistant costs the same as from the dashboard or the API; see the pricing page. New accounts get €0.50 free credit, sign-up is free.