guzzlehttp/promises

Guzzle promises library

3.0.0 2026-07-20 13:44 UTC

Requires

• php: ^7.4 || ^8.0

Requires (Dev)

• bamarni/composer-bin-plugin: ^1.8.2
• phpunit/phpunit: ^9.6.34

MIT

• Graham Campbell
• Michael Dowling
• Tobias Nyholm
• Tobias Schultze

• promise

Published on Packagist.org on 2026-07-20 13:45 UTC

README

guzzlehttp/promises is a small promise library used by Guzzle for asynchronous operations. It implements promise chaining, synchronous waiting, cancellation, and helpers for working with groups of promises.

Most application developers use this package through guzzlehttp/guzzle by calling methods such as requestAsync(). Install this package directly when you need promise composition without the full HTTP client.

Installation

composer require guzzlehttp/promises

Version Guidance

Version	Status	PHP Version
3.0	Latest	>=7.4,<8.6
2.5	Maintenance	>=7.2.5,<8.6
1.5	End of Life	>=5.5,<8.3

Quick Start

use GuzzleHttp\Promise\Promise;
use GuzzleHttp\Promise\Utils;

$promise = new Promise();

$promise->then(
    function ($value) {
        echo 'Fulfilled: ' . $value;
    },
    function ($reason) {
        echo 'Rejected: ' . $reason;
    }
);

$promise->resolve('done');
Utils::queue()->run();

You can wait for a promise to complete synchronously:

$value = $promise->wait();

When using Guzzle HTTP requests, asynchronous methods return GuzzleHttp\Promise\PromiseInterface instances:

$promise = $client->requestAsync('GET', 'https://example.com');
$response = $promise->wait();

Documentation

• Promise Quick Start
• Promise API
• Promise Interoperability
• Implementation Notes
• Upgrade Guide
• Changelog

Security

If you discover a security vulnerability within this package, please send an email to [e-mail]. All security vulnerabilities will be promptly addressed. Please do not disclose security-related issues publicly until a fix has been announced. Please see Security Policy for more information.

License

Guzzle is made available under the MIT License (MIT). Please see License File for more information.

For Enterprise

Available as part of the Tidelift Subscription

The maintainers of Guzzle and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. Learn more.