> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.pinnacle.sh/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.pinnacle.sh/_mcp/server.

# Sending SMS Messages

> Sending your first SMS with Pinnacle's Python SDK

```python
from rcs import Pinnacle
from dotenv import load_dotenv
import os

# Load environment variables
load_dotenv()

API_KEY = os.getenv("PINNACLE_API_KEY")
SENDER_NUMBER = os.getenv("SENDER_NUMBER")

# Initialize the Pinnacle client
client = Pinnacle(
  api_key=API_KEY,
)

# Send an SMS message
client.messages.sms.send(
  from_=SENDER_NUMBER,
  text="Hello, world!",
  to="+14154746461", # Recipient's phone number
)
```

## Prerequisites

Before proceeding, ensure you have obtained a phone number and API key as described in the [prerequisites](/quickstart/sms).

## Installation

Create a Python virtual environment:

```bash
python3 -m venv venv
```

Activate the virtual environment:

```bash
source venv/bin/activate
```

Install the Pinnacle Python SDK:

```bash
pip install rcs
```

> **Info**
>
> This guide uses version `rcs>=2.0.4`. Requires: Python \<4.0, >=3.8

## Configuration

Create an `.env` file in your project root and add your Pinnacle API key:

```
PINNACLE_API_KEY="your_api_key" # pnclk_
SENDER_NUMBER="your_phone_number" # +12345678910
```

## Sending Your First SMS

Create a new Python file (e.g., `main.py`) and add the following code to the right.

Run the script:

```bash
python main.py
```

If successful, the recipient will receive your SMS message!