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# Welcome

> Build messaging and voice integrations with AgentPhone. Choose an API, SDK, or MCP workflow.

AgentPhone gives your application phone numbers for messaging and voice calls. Use the REST API or SDKs from your backend, or connect an AI assistant through MCP.

## Choose your starting point

#### [API quickstart](/docs/quickstart)

Create an agent, attach a number, and verify an inbound message.

#### [Connect your AI](/docs/integrations/connect-your-ai)

Connect an MCP client to use phone tools through your assistant.

#### [API reference](/docs/api-reference)

Find request fields, response schemas, and endpoint details.

## Choose a channel

| Goal                                      | Start here                                                                                          | Before sending                                                                                           |
| ----------------------------------------- | --------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------- |
| Send SMS or MMS from a US/Canadian number | [Phone numbers](/docs/documentation/guides/phone-numbers) and [Messages](/docs/documentation/guides/messages) | Complete [SMS registration](/docs/sms-registration) and check the number's `outboundSms` status.              |
| Send iMessage                             | [Set up iMessage](/docs/imessage)                                                                        | Purchase an iMessage line; a standard SMS number does not become an iMessage line automatically.         |
| Send WhatsApp messages                    | [WhatsApp](/docs/documentation/guides/whatsapp)                                                          | Connect your WhatsApp Business Account and use an approved template outside the customer service window. |
| Send branded RCS                          | [RCS Business Messaging](/docs/documentation/guides/rcs)                                                 | Request onboarding for an RCS sender.                                                                    |
| Build a voice assistant                   | [Agents](/docs/documentation/guides/agents) and [Calls](/docs/documentation/guides/calls)                     | Choose hosted AI or your own voice webhook. Outbound phone calls also have a billing prerequisite.       |
| Connect your own voice platform           | [SIP trunking](/docs/sip-trunking)                                                                       | Request SIP access and configure voice routing.                                                          |

## How the resources fit together

* **Account / project:** the scope for API keys, numbers, agents, and the default webhook. Use a [sub-account](/docs/sub-accounts) to isolate a client or campaign.
* **Agent:** configuration for a voice persona and a way to route a number's events. One agent can have several numbers; a number can be attached to one agent.
* **Number:** your sending address and inbound destination. Capabilities and billing depend on the number type.
* **Conversation:** message history between one of your numbers and a contact or group. It can hold application metadata.
* **Call:** a voice session with its own status, transcript, and optional recording.
* **Webhook:** your HTTPS endpoint for inbound events. A per-agent webhook overrides the account default.

`voiceMode: "hosted"` supplies the AI for **voice**. It does not automatically answer text messages. Your application receives text events and sends replies through `POST /v1/messages`.

## Quick start

Follow the [API quickstart](/docs/quickstart) for prerequisites, commands, expected results, and a first-message check. For credentials and account selection, read [Authentication](/docs/authentication).

## Find help

Start with [Troubleshooting](/docs/troubleshooting) for SMS activation, iMessage restrictions, webhook delivery, calls, and billing. When contacting [support](mailto:founders@agentphone.to), include the response's `X-Request-Id`, the relevant resource IDs, and a redacted request. You can also [submit API feedback](/docs/feedback).