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

# Inboxapp API quickstart

> Get an API key and call the Inboxapp API. The full reference lives in the API docs.

Use the Inboxapp API to manage inboxes and messages from your own apps. Full reference: [API overview](/developer-api) · [Quickstart](/quickstart).

## Prerequisites

* An Inboxapp account
* An **API key** from account settings (treat it like a password)
* Optional: Postman or cURL for testing

## Base URL

`https://inboxapp.com/api/v1`

Authenticate with a Bearer token using your API key in the `Authorization` header.

## Common tasks

Follow the official guides for listing inboxes, working with threads, and sending messages:

* [Quickstart](/quickstart)
* [Messages](/guides/messages)

**Note:** Replying to existing conversations works on all plans. Sending the **first message** to a new contact needs the outbound/API add-on described in Billing — [Plans and credits](/help/billing/billing-plans-and-credits).

## Related

* [Plans and credits](/help/billing/billing-plans-and-credits)
* [API collection](/help/api)

Still stuck? Contact support from the app, or email [support@inboxapp.com](mailto:support@inboxapp.com) for API issues.