mailbox

sendmux/mailbox

Sendmux Mailbox API client for PHP.

Read the PHP SDK guide at sendmux.ai/docs/sdks/php.

Requirements

• PHP 8.2 or newer.
• Composer.
• A mailbox-scoped smx_mbx_ key or scoped smx_agent_ token.

Installation

composer require sendmux/mailbox:^1.0

Usage

Create the Mailbox API client with a mailbox-scoped key or scoped agent token.

<?php

require __DIR__ . '/vendor/autoload.php';

use Sendmux\Mailbox\ClientFactory;

$mailboxApi = ClientFactory::createMailboxAPIApi(
    getenv('SENDMUX_MAILBOX_API_KEY') ?: ''
);

The generated MailboxAPIApi exposes mailbox methods such as mailboxGetMe(), mailboxListMessages(), mailboxSendMessage(), and mailboxUploadAttachment().

Attachments and events

Message and event attachment metadata includes download_url, a short-lived presigned URL for that single attachment. Fetch it promptly with a plain HTTP client and no Authorization header. If it expires, re-fetch the message or attachment metadata to receive a fresh URL.

Use mailboxUploadAttachment() to upload bytes and pass the returned blob_id into mailboxSendMessage() attachments. Inline base64 attachments remain available in the generated send body shape for small payloads.

mailboxStreamEvents() exposes the Mailbox SSE endpoint for clients that want live message.received events.

Features

• Validates smx_mbx_ keys or scoped smx_agent_ tokens before configuring the client.
• Uses https://app.sendmux.ai/api/v1 by default.
• Adds retry and rate-limit backoff behaviour through sendmux/core.
• Covers mailbox identity, folders, messages, attachments, submissions, threads, quota, usage, and event streams.
• Includes generated models for Mailbox API requests and responses.

Related packages

Package	Use it for
sendmux/core	Shared helpers for auth, headers, retries, pagination, and errors.
sendmux/sending	Sending API client.
sendmux/management	Management API client.
sendmux/sdk	Umbrella package that installs all PHP SDK surfaces.

Support

For help, include the package name, version, API surface, and sanitised request details. Do not include API keys, tokens, passwords, webhook secrets, customer data, or private account details.

• PHP SDK guide: sendmux.ai/docs/sdks/php
• Mailbox API reference: sendmux.ai/docs/mailbox-api/introduction
• API keys guide: sendmux.ai/docs/guides/api-keys
• Source repository: github.com/Sendmux/sendmux-sdk

License

MIT. See LICENSE.