# ErzyCall API Documentation

> API docs for the ErzyCall REST API

- [Authentication](/docs/authentication): How to authenticate with the ErzyCall REST API using API keys.
- [Error Handling](/docs/error-handling): Understand the error response format and common error codes.
- [Quick Start](/docs): Get up and running with the ErzyCall REST API in minutes.
- [Rate Limiting](/docs/rate-limiting): Understand the ErzyCall API rate limits and how to handle 429 responses.
- [Webhooks](/docs/webhooks): Receive real-time event notifications via webhooks.
- [Assistants](/docs/api-reference/assistants): List and manage inbound and outbound AI voice assistants.
- [Calls](/docs/api-reference/calls): List, create, view, and cancel voice calls.
- [Cases](/docs/api-reference/cases): Create, read, update, and delete case records — reusable call scripts with AI instructions.
- [Contact Groups](/docs/api-reference/contact-groups): List contact groups for your organization.
- [Contacts](/docs/api-reference/contacts): Create, read, update, delete, and search contacts.
- [Organization](/docs/api-reference/organization): Identify the organization connected to your API key or OAuth token.
- [Phone Numbers](/docs/api-reference/phone-numbers): List phone numbers assigned to your organization.
- [Usage](/docs/api-reference/usage): Read your organization's plan, minute balance, spend, and usage history.
- [Webhook Endpoints](/docs/api-reference/webhook-endpoints): Create, update, and manage webhook endpoint subscriptions.
- [WhatsApp](/docs/api-reference/whatsapp): Access connected WhatsApp Business accounts, send messages, and manage chat threads.
- [Automation platforms](/docs/mcp/automation): Connect ErzyCall to n8n, Make.com, and Zapier.
- [Chat assistants](/docs/mcp/chat-assistants): Connect ChatGPT, Claude, or another AI to your ErzyCall organization.
- [Coding tools](/docs/mcp/coding-tools): Add ErzyCall to Claude Code, Cursor, Hermes, VS Code, Windsurf/Devin, and Zed.
- [Overview](/docs/mcp): Connect ErzyCall to ChatGPT, Claude, or your automation platform over MCP.
- [Tools & permissions](/docs/mcp/tools): What your assistant can do once ErzyCall is connected, and what each permission grants.
- [Troubleshooting](/docs/mcp/troubleshooting): Fixes for the failures people actually hit, plus a compatibility table.