> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.pinnacle.sh/v-2/documentation/authentication/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.pinnacle.sh/_mcp/server.

# Authentication

> Secure your API requests with Pinnacle API keys

## Overview

The Pinnacle API authenticates requests using API keys that you can generate and manage in your [Pinnacle Dashboard](https://app.pinnacle.sh/dashboard/development/api-keys). Every API request must include a valid API key to access Pinnacle's services.

## Using Your API Key

Pinnacle uses the `PINNACLE-API-KEY` header for authentication. Include your API key in every request:

```bash
curl -X GET "https://api.pinnacle.sh/status" \
  -H "PINNACLE-API-KEY: your_api_key_here"
```

## Authentication Errors

If your API key is missing, invalid, or expired, Pinnacle will return a `401 Unauthorized` response:

```json
{
  "error": "Invalid API key."
}
```

> One API for RCS, iMessage, MMS, and SMS. Build, test, and scale every channel — send your first message in minutes, not weeks.