sms8-mcp

v1.1.1

Published

15 days ago

MCP server for SMS + OTP. Twilio alternative for AI agents — let Claude Code, Cursor, Windsurf, and OpenCode send SMS, OTPs, and verification codes through your own Android phone. Free 5-day trial at sms8.io. No per-message fees, no markups, no A2P 10DLC.

sms8-mcp — SMS gateway MCP server for Claude Code, Cursor, Windsurf

Plug SMS into any AI coding tool that speaks the Model Context Protocol. Your assistant can now send SMS, generate and verify OTPs, wait for incoming codes, list inbox messages, and configure webhooks — through your own Android phone rather than Twilio.

Add to any MCP client config and you're done:

{
  "mcpServers": {
    "sms8": {
      "command": "npx",
      "args": ["-y", "sms8-mcp"],
      "env": { "SMS8_API_KEY": "sk_xxx" }
    }
  }
}

What it does

Exposes 9 tools to your AI assistant:

| Tool | What it does | |---|---| | setup_sms8 | Validate the API key, return account context and code samples | | send_sms | Send one SMS to one phone number | | send_otp | Generate and send a verification code | | verify_otp | Compare a typed code against the latest issued OTP | | wait_for_otp | Block until an OTP arrives on the paired Android; extract the code | | list_devices | List paired Android phones (model, primary flag, enabled) | | get_messages | Recent inbox or sent items, filter by direction, limit, phone | | get_balance | Account credits + expiry + paired-device count | | create_webhook | Register an inbound-SMS webhook URL |

Why use this

Real SMS from your AI assistant — Claude / Cursor / Windsurf can text users without a Twilio account
OTP loops your AI can complete end-to-end — send_otp → wait_for_otp lets agents handle phone verification in tests, signups, password resets
No CPaaS fees — your own Android SIM is the sender; $29/month flat unlimited
No A2P 10DLC paperwork (US) — these are P2P messages from a real phone

Install

You don't have to install anything — npx -y sms8-mcp does it on demand inside the MCP config. The launcher is ~10 KB.

To install globally:

npm install -g sms8-mcp

Node 18 or newer.

Get an API key

Sign up free at sms8.io (5-day trial, no card required)
Install the SMS8 Android app, pair your phone
Copy your API key from app.sms8.io/api.php

Client config

Claude Code

~/.claude/config.json or per-project .mcp.json:

{
  "mcpServers": {
    "sms8": {
      "command": "npx",
      "args": ["-y", "sms8-mcp"],
      "env": { "SMS8_API_KEY": "sk_xxx" }
    }
  }
}

Cursor

~/.cursor/mcp.json:

{
  "mcpServers": {
    "sms8": {
      "command": "npx",
      "args": ["-y", "sms8-mcp"],
      "env": { "SMS8_API_KEY": "sk_xxx" }
    }
  }
}

Windsurf

~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "sms8": {
      "command": "npx",
      "args": ["-y", "sms8-mcp"],
      "env": { "SMS8_API_KEY": "sk_xxx" }
    }
  }
}

OpenCode

Add to opencode.json:

{
  "mcp": {
    "sms8": {
      "command": "npx",
      "args": ["-y", "sms8-mcp"],
      "env": { "SMS8_API_KEY": "sk_xxx" }
    }
  }
}

Claude.ai web (Custom Connector)

Connect directly to the hosted MCP — no local install needed. Add https://mcp.sms8.io as a connector in claude.ai → Settings → Connectors. Then ask: "Send SMS via SMS8 to +1234 saying Hi".

Example prompts to try

After adding the connector and restarting your client:

"Use sms8 to send +14155550100 'Test from Claude'"
"Send an OTP code to +14155550100, then wait until it arrives and tell me the code"
"Show me my SMS8 inbox from the last hour"
"Which Android devices are paired with my SMS8 account?"

How it works

Your AI client launches npx -y sms8-mcp over stdio
The launcher forwards JSON-RPC frames to the hosted MCP server at https://mcp.sms8.io, adding Authorization: Bearer <SMS8_API_KEY> to each call
The MCP server validates the key, runs the tool against your SMS8 account, and queues the SMS
Your paired Android phone polls SMS8, sends the SMS via its real SIM, and reports back
The result returns up the chain to your AI assistant

Round-trip is typically under 4 seconds.

Environment variables

| Variable | Default | Purpose | |---|---|---| | SMS8_API_KEY | (required) | Your API key from app.sms8.io | | SMS8_BASE_URL | https://mcp.sms8.io | Override server (rare; for self-hosted) |

Want CLI instead?

If you want to call SMS8 from shell scripts, cron, CI without an AI loop, use the companion package sms8-cli:

npx sms8-cli send +14155550100 "Hi"
npx sms8-cli otp send +14155550100
CODE=$(npx sms8-cli otp wait +14155550100 --timeout=120)

License

MIT