> ## Documentation Index
> Fetch the complete documentation index at: https://support.quo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# APIs

> Integrate Quo, formerly OpenPhone's communication capabilities into your applications with our developer API

## Overview

The Quo API enables developers to integrate Quo's communication capabilities directly into their applications and workflows. Send messages, manage contacts, and automate communication processes programmatically.

<Note>
  API access requires an active Quo subscription and Owner or Admin permissions for your workspace.
</Note>

## Getting started with the API

### Prerequisites

**Requirements for API access:**

* Active Quo subscription (any plan)
* Owner or Admin role in your workspace
* Completed US carrier registration for messaging to US numbers
* Prepaid credits for API messaging

### API documentation

Access comprehensive API documentation and resources:

[**Available in our API documentation:**](https://www.quo.com/docs/mdx/api-reference/introduction)

* Step-by-step setup and authentication
* Complete endpoint reference
* Code examples and SDKs
* Rate limits and best practices
* Pricing and billing information

## API capabilities

### Core functionality

**Available API endpoints:**

* **Send messages**: Programmatically send SMS
* **Manage contacts**: Create, update, and organize contacts
* **Retrieve conversations**: Access message history and threads
* **Webhook integration**: Receive real-time event notifications

### Messaging features

**Supported message types:**

* SMS text messages to US, Canadian, and international numbers
* Group messaging capabilities
* Message status tracking and delivery confirmation

## Pricing and billing

### API message costs

**Prepaid credit system:**

* **US and Canadian messages**: \$0.01 per message segment
* **International messages**: \$0.01 per segment + international rates
* **Prepaid credits required**: Purchase through billing settings
* **No monthly API fees**: Pay only for messages sent

<Warning>
  API messaging requires prepaid credits. Messages will fail if insufficient credits are available.
</Warning>

### Message segments

**How message segments work:**

* Standard SMS: 160 characters = 1 segment
* Unicode/emoji SMS: 70 characters = 1 segment
* Longer messages automatically split into multiple segments
* MMS messages count as single segment regardless of content size

## Authentication and security

### API keys

**Secure authentication:**

* Generate API keys through workspace settings
* Keys provide secure access to your workspace data
* Regenerate keys if compromised
* Use environment variables to store keys securely

### Rate limits

**API usage limits:**

* Designed to prevent abuse and ensure reliability
* Limits vary by endpoint and subscription level
* Monitor usage through API responses

## Integration examples

### Common use cases

**Popular API implementations:**

* **Customer notifications**: Order updates, appointment reminders
* **Marketing automation**: Promotional campaigns, follow-up sequences
* **Support workflows**: Ticket notifications, status updates
* **CRM integration**: Sync contacts and communication history

### Development resources

**Getting started quickly:**

* Interactive API explorer in documentation
* Code samples in multiple programming languages
* Postman collection for testing
* Community examples and templates

## Related integrations

Explore pre-built integrations that complement API usage:

<Info>
  View all available integrations on our [integrations page](https://www.quo.com/integrations), including Salesforce, HubSpot, and Gong.
</Info>