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.

composer require guzzlehttp/promises

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();

A promise's getState() describes how it was settled, not the eventual outcome: a promise that was resolved with another promise, directly or by returning one from a then() handler, reports fulfilled while the inner promise may still be pending, and wait() can still throw if the inner promise rejects. Poll the state only on promises settled with plain values, or call wait() first (see guzzle/promises#101).

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

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

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

If you discover a security vulnerability within this package, please send an email to [email protected]. All security vulnerabilities will be promptly addressed by the security maintainers listed in the Security Policy. Please do not disclose security-related issues publicly until a fix has been announced.

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

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