Guzzle Upgrade Guide

5.0 to 6.0

Guzzle now uses PSR-7 for HTTP messages.
Due to the fact that these messages are immutable, this prompted a refactoring
of Guzzle to use a middleware based system rather than an event system. Any
HTTP message interaction (e.g., GuzzleHttp\Message\Request) need to be
updated to work with the new immutable PSR-7 request and response objects. Any
event listeners or subscribers need to be updated to become middleware
functions that wrap handlers (or are injected into a
GuzzleHttp\HandlerStack).

Removed GuzzleHttp\BatchResults
Removed GuzzleHttp\Collection
Removed GuzzleHttp\HasDataTrait
Removed GuzzleHttp\ToArrayInterface
The guzzlehttp/streams dependency has been removed. Stream functionality
is now present in the GuzzleHttp\Psr7 namespace provided by the
guzzlehttp/psr7 package.
Guzzle no longer uses ReactPHP promises and now uses the
guzzlehttp/promises library. We use a custom promise library for three
significant reasons:

React promises (at the time of writing this) are recursive. Promise
chaining and promise resolution will eventually blow the stack. Guzzle
promises are not recursive as they use a sort of trampolining technique.
Note: there has been movement in the React project to modify promises to
no longer utilize recursion.
Guzzle needs to have the ability to synchronously block on a promise to
wait for a result. Guzzle promises allows this functionality (and does
not require the use of recursion).
Because we need to be able to wait on a result, doing so using React
promises requires wrapping react promises with RingPHP futures. This
overhead is no longer needed, reducing stack sizes, reducing complexity,
and improving performance.

GuzzleHttp\Mimetypes has been moved to a function in
GuzzleHttp\Psr7\mimetype_from_extension and
GuzzleHttp\Psr7\mimetype_from_filename.
GuzzleHttp\Query and GuzzleHttp\QueryParser have been removed. Query
strings must now be passed into request objects as strings, or provided to
the query request option when creating requests with clients. The query
option uses PHP's http_build_query to convert an array to a string. If you
need a different serialization technique, you will need to pass the query
string in as a string. There are a couple helper functions that will make
working with query strings easier: GuzzleHttp\Psr7\parse_query and
GuzzleHttp\Psr7\build_query.
Guzzle no longer has a dependency on RingPHP. Due to the use of a middleware
system based on PSR-7, using RingPHP and it's middleware system as well adds
more complexity than the benefits it provides. All HTTP handlers that were
present in RingPHP have been modified to work directly with PSR-7 messages
and placed in the GuzzleHttp\Handler namespace. This significantly reduces
complexity in Guzzle, removes a dependency, and improves performance. RingPHP
will be maintained for Guzzle 5 support, but will no longer be a part of
Guzzle 6.
As Guzzle now uses a middleware based systems the event system and RingPHP
integration has been removed. Note: while the event system has been removed,
it is possible to add your own type of event system that is powered by the
middleware system.
Removed the Event namespace.
Removed the Subscriber namespace.
Removed Transaction class
Removed RequestFsm
Removed RingBridge
GuzzleHttp\Subscriber\Cookie is now provided by
GuzzleHttp\Middleware::cookies
GuzzleHttp\Subscriber\HttpError is now provided by
GuzzleHttp\Middleware::httpError
GuzzleHttp\Subscriber\History is now provided by
GuzzleHttp\Middleware::history
GuzzleHttp\Subscriber\Mock is now provided by
GuzzleHttp\Handler\MockHandler
GuzzleHttp\Subscriber\Prepare is now provided by
GuzzleHttp\PrepareBodyMiddleware
GuzzleHttp\Subscriber\Redirect is now provided by
GuzzleHttp\RedirectMiddleware
Guzzle now uses Psr\Http\Message\UriInterface (implements in
GuzzleHttp\Psr7\Uri) for URI support. GuzzleHttp\Url is now gone.
Static functions in GuzzleHttp\Utils have been moved to namespaced
functions under the GuzzleHttp namespace. This requires either a Composer
based autoloader or you to include functions.php.
GuzzleHttp\ClientInterface::getDefaultOption has been renamed to
GuzzleHttp\ClientInterface::getConfig.
GuzzleHttp\ClientInterface::setDefaultOption has been removed.
The json and xml methods of response objects has been removed. With the
migration to strictly adhering to PSR-7 as the interface for Guzzle messages,
adding methods to message interfaces would actually require Guzzle messages
to extend from PSR-7 messages rather then work with them directly.

Migrating to middleware

The change to PSR-7 unfortunately required significant refactoring to Guzzle
due to the fact that PSR-7 messages are immutable. Guzzle 5 relied on an event
system from plugins. The event system relied on mutability of HTTP messages and
side effects in order to work. With immutable messages, you have to change your
workflow to become more about either returning a value (e.g., functional
middlewares) or setting a value on an object. Guzzle v6 has chosen the
functional middleware approach.

Instead of using the event system to listen for things like the before event,
you now create a stack based middleware function that intercepts a request on
the way in and the promise of the response on the way out. This is a much
simpler and more predictable approach than the event system and works nicely
with PSR-7 middleware. Due to the use of promises, the middleware system is
also asynchronous.

v5:

use GuzzleHttp\Event\BeforeEvent;
$client = new GuzzleHttp\Client();
// Get the emitter and listen to the before event.
$client->getEmitter()->on('before', function (BeforeEvent $e) {
    // Guzzle v5 events relied on mutation
    $e->getRequest()->setHeader('X-Foo', 'Bar');
});

v6:

In v6, you can modify the request before it is sent using the mapRequest
middleware. The idiomatic way in v6 to modify the request/response lifecycle is
to setup a handler middleware stack up front and inject the handler into a
client.

use GuzzleHttp\Middleware;
// Create a handler stack that has all of the default middlewares attached
$handler = GuzzleHttp\HandlerStack::create();
// Push the handler onto the handler stack
$handler->push(Middleware::mapRequest(function (RequestInterface $request) {
    // Notice that we have to return a request object
    return $request->withHeader('X-Foo', 'Bar');
}));
// Inject the handler into the client
$client = new GuzzleHttp\Client(['handler' => $handler]);

POST Requests

This version added the form_params
and multipart request options. form_params is an associative array of
strings or array of strings and is used to serialize an
application/x-www-form-urlencoded POST request. The
multipart
option is now used to send a multipart/form-data POST request.

GuzzleHttp\Post\PostFile has been removed. Use the multipart option to add
POST files to a multipart/form-data request.

The body option no longer accepts an array to send POST requests. Please use
multipart or form_params instead.

The base_url option has been renamed to base_uri.

4.x to 5.0

Rewritten Adapter Layer

Guzzle now uses RingPHP to send
HTTP requests. The adapter option in a GuzzleHttp\Client constructor
is still supported, but it has now been renamed to handler. Instead of
passing a GuzzleHttp\Adapter\AdapterInterface, you must now pass a PHP
callable that follows the RingPHP specification.

Removed Fluent Interfaces

Fluent interfaces were removed
from the following classes:

GuzzleHttp\Collection
GuzzleHttp\Url
GuzzleHttp\Query
GuzzleHttp\Post\PostBody
GuzzleHttp\Cookie\SetCookie

Removed functions.php

Removed "functions.php", so that Guzzle is truly PSR-4 compliant. The following
functions can be used as replacements.

GuzzleHttp\json_decode -> GuzzleHttp\Utils::jsonDecode
GuzzleHttp\get_path -> GuzzleHttp\Utils::getPath
GuzzleHttp\Utils::setPath -> GuzzleHttp\set_path
GuzzleHttp\Pool::batch -> GuzzleHttp\batch. This function is, however,
deprecated in favor of using GuzzleHttp\Pool::batch().

The "procedural" global client has been removed with no replacement (e.g.,
GuzzleHttp\get(), GuzzleHttp\post(), etc.). Use a GuzzleHttp\Client
object as a replacement.

`throwImmediately` has been removed

The concept of "throwImmediately" has been removed from exceptions and error
events. This control mechanism was used to stop a transfer of concurrent
requests from completing. This can now be handled by throwing the exception or
by cancelling a pool of requests or each outstanding future request
individually.

headers event has been removed

Removed the "headers" event. This event was only useful for changing the
body a response once the headers of the response were known. You can implement
a similar behavior in a number of ways. One example might be to use a
FnStream that has access to the transaction being sent. For example, when the
first byte is written, you could check if the response headers match your
expectations, and if so, change the actual stream body that is being
written to.

Updates to HTTP Messages

Removed the asArray parameter from
GuzzleHttp\Message\MessageInterface::getHeader. If you want to get a header
value as an array, then use the newly added getHeaderAsArray() method of
MessageInterface. This change makes the Guzzle interfaces compatible with
the PSR-7 interfaces.

3.x to 4.0

Overarching changes:

Now requires PHP 5.4 or greater.
No longer requires cURL to send requests.
Guzzle no longer wraps every exception it throws. Only exceptions that are
recoverable are now wrapped by Guzzle.
Various namespaces have been removed or renamed.
No longer requiring the Symfony EventDispatcher. A custom event dispatcher
based on the Symfony EventDispatcher is
now utilized in GuzzleHttp\Event\EmitterInterface (resulting in significant
speed and functionality improvements).

Changes per Guzzle 3.x namespace are described below.

Batch

The Guzzle\Batch namespace has been removed. This is best left to
third-parties to implement on top of Guzzle's core HTTP library.

Cache

The Guzzle\Cache namespace has been removed. (Todo: No suitable replacement
has been implemented yet, but hoping to utilize a PSR cache interface).

Common

Removed all of the wrapped exceptions. It's better to use the standard PHP
library for unrecoverable exceptions.
FromConfigInterface has been removed.
Guzzle\Common\Version has been removed. The VERSION constant can be found
at GuzzleHttp\ClientInterface::VERSION.

Collection

getAll has been removed. Use toArray to convert a collection to an array.
inject has been removed.
keySearch has been removed.
getPath no longer supports wildcard expressions. Use something better like
JMESPath for this.
setPath now supports appending to an existing array via the [] notation.

Events

Guzzle no longer requires Symfony's EventDispatcher component. Guzzle now uses
GuzzleHttp\Event\Emitter.

Symfony\Component\EventDispatcher\EventDispatcherInterface is replaced by
GuzzleHttp\Event\EmitterInterface.
Symfony\Component\EventDispatcher\EventDispatcher is replaced by
GuzzleHttp\Event\Emitter.
Symfony\Component\EventDispatcher\Event is replaced by
GuzzleHttp\Event\Event, and Guzzle now has an EventInterface in
GuzzleHttp\Event\EventInterface.
AbstractHasDispatcher has moved to a trait, HasEmitterTrait, and
HasDispatcherInterface has moved to HasEmitterInterface. Retrieving the
event emitter of a request, client, etc. now uses the getEmitter method
rather than the getDispatcher method.

Emitter

Use the once() method to add a listener that automatically removes itself
the first time it is invoked.
Use the listeners() method to retrieve a list of event listeners rather than
the getListeners() method.
Use emit() instead of dispatch() to emit an event from an emitter.
Use attach() instead of addSubscriber() and detach() instead of
removeSubscriber().

$mock = new Mock();
// 3.x
$request->getEventDispatcher()->addSubscriber($mock);
$request->getEventDispatcher()->removeSubscriber($mock);
// 4.x
$request->getEmitter()->attach($mock);
$request->getEmitter()->detach($mock);

Use the on() method to add a listener rather than the addListener() method.

// 3.x
$request->getEventDispatcher()->addListener('foo', function (Event $event) { /* ... */ } );
// 4.x
$request->getEmitter()->on('foo', function (Event $event, $name) { /* ... */ } );

Http

General changes

The cacert.pem certificate has been moved to src/cacert.pem.
Added the concept of adapters that are used to transfer requests over the
wire.
Simplified the event system.
Sending requests in parallel is still possible, but batching is no longer a
concept of the HTTP layer. Instead, you must use the complete and error
events to asynchronously manage parallel request transfers.
Guzzle\Http\Url has moved to GuzzleHttp\Url.
Guzzle\Http\QueryString has moved to GuzzleHttp\Query.
QueryAggregators have been rewritten so that they are simply callable
functions.
GuzzleHttp\StaticClient has been removed. Use the functions provided in
functions.php for an easy to use static client instance.
Exceptions in GuzzleHttp\Exception have been updated to all extend from
GuzzleHttp\Exception\TransferException.

Client

Calling methods like get(), post(), head(), etc. no longer create and
return a request, but rather creates a request, sends the request, and returns
the response.

// 3.0
$request = $client->get('/');
$response = $request->send();

// 4.0
$response = $client->get('/');

// or, to mirror the previous behavior
$request = $client->createRequest('GET', '/');
$response = $client->send($request);

GuzzleHttp\ClientInterface has changed.

The send method no longer accepts more than one request. Use sendAll to
send multiple requests in parallel.
setUserAgent() has been removed. Use a default request option instead. You
could, for example, do something like:
$client->setConfig('defaults/headers/User-Agent', 'Foo/Bar ' . $client::getDefaultUserAgent()).
setSslVerification() has been removed. Use default request options instead,
like $client->setConfig('defaults/verify', true).

GuzzleHttp\Client has changed.

The constructor now accepts only an associative array. You can include a
base_url string or array to use a URI template as the base URL of a client.
You can also specify a defaults key that is an associative array of default
request options. You can pass an adapter to use a custom adapter,
batch_adapter to use a custom adapter for sending requests in parallel, or
a message_factory to change the factory used to create HTTP requests and
responses.
The client no longer emits a client.create_request event.
Creating requests with a client no longer automatically utilize a URI
template. You must pass an array into a creational method (e.g.,
createRequest, get, put, etc.) in order to expand a URI template.

Messages

Messages no longer have references to their counterparts (i.e., a request no
longer has a reference to it's response, and a response no loger has a
reference to its request). This association is now managed through a
GuzzleHttp\Adapter\TransactionInterface object. You can get references to
these transaction objects using request events that are emitted over the
lifecycle of a request.

Requests with a body

GuzzleHttp\Message\EntityEnclosingRequest and
GuzzleHttp\Message\EntityEnclosingRequestInterface have been removed. The
separation between requests that contain a body and requests that do not
contain a body has been removed, and now GuzzleHttp\Message\RequestInterface
handles both use cases.
Any method that previously accepts a GuzzleHttp\Response object now accept a
GuzzleHttp\Message\ResponseInterface.
GuzzleHttp\Message\RequestFactoryInterface has been renamed to
GuzzleHttp\Message\MessageFactoryInterface. This interface is used to create
both requests and responses and is implemented in
GuzzleHttp\Message\MessageFactory.
POST field and file methods have been removed from the request object. You
must now use the methods made available to GuzzleHttp\Post\PostBodyInterface
to control the format of a POST body. Requests that are created using a
standard GuzzleHttp\Message\MessageFactoryInterface will automatically use
a GuzzleHttp\Post\PostBody body if the body was passed as an array or if
the method is POST and no body is provided.

$request = $client->createRequest('POST', '/');
$request->getBody()->setField('foo', 'bar');
$request->getBody()->addFile(new PostFile('file_key', fopen('/path/to/content', 'r')));

Headers

GuzzleHttp\Message\Header has been removed. Header values are now simply
represented by an array of values or as a string. Header values are returned
as a string by default when retrieving a header value from a message. You can
pass an optional argument of true to retrieve a header value as an array
of strings instead of a single concatenated string.
GuzzleHttp\PostFile and GuzzleHttp\PostFileInterface have been moved to
GuzzleHttp\Post. This interface has been simplified and now allows the
addition of arbitrary headers.
Custom headers like GuzzleHttp\Message\Header\Link have been removed. Most
of the custom headers are now handled separately in specific
subscribers/plugins, and GuzzleHttp\Message\HeaderValues::parseParams() has
been updated to properly handle headers that contain parameters (like the
Link header).

Responses

GuzzleHttp\Message\Response::getInfo() and
GuzzleHttp\Message\Response::setInfo() have been removed. Use the event
system to retrieve this type of information.
GuzzleHttp\Message\Response::getRawHeaders() has been removed.
GuzzleHttp\Message\Response::getMessage() has been removed.
GuzzleHttp\Message\Response::calculateAge() and other cache specific
methods have moved to the CacheSubscriber.
Header specific helper functions like getContentMd5() have been removed.
Just use getHeader('Content-MD5') instead.
GuzzleHttp\Message\Response::setRequest() and
GuzzleHttp\Message\Response::getRequest() have been removed. Use the event
system to work with request and response objects as a transaction.
GuzzleHttp\Message\Response::getRedirectCount() has been removed. Use the
Redirect subscriber instead.
GuzzleHttp\Message\Response::isSuccessful() and other related methods have
been removed. Use getStatusCode() instead.

Streaming responses

Streaming requests can now be created by a client directly, returning a
GuzzleHttp\Message\ResponseInterface object that contains a body stream
referencing an open PHP HTTP stream.

// 3.0
use Guzzle\Stream\PhpStreamRequestFactory;
$request = $client->get('/');
$factory = new PhpStreamRequestFactory();
$stream = $factory->fromRequest($request);
$data = $stream->read(1024);

// 4.0
$response = $client->get('/', ['stream' => true]);
// Read some data off of the stream in the response body
$data = $response->getBody()->read(1024);

Redirects

The configureRedirects() method has been removed in favor of a
allow_redirects request option.

// Standard redirects with a default of a max of 5 redirects
$request = $client->createRequest('GET', '/', ['allow_redirects' => true]);

// Strict redirects with a custom number of redirects
$request = $client->createRequest('GET', '/', [
    'allow_redirects' => ['max' => 5, 'strict' => true]
]);

EntityBody

EntityBody interfaces and classes have been removed or moved to
GuzzleHttp\Stream. All classes and interfaces that once required
GuzzleHttp\EntityBodyInterface now require
GuzzleHttp\Stream\StreamInterface. Creating a new body for a request no
longer uses GuzzleHttp\EntityBody::factory but now uses
GuzzleHttp\Stream\Stream::factory or even better:
GuzzleHttp\Stream\create().

Guzzle\Http\EntityBodyInterface is now GuzzleHttp\Stream\StreamInterface
Guzzle\Http\EntityBody is now GuzzleHttp\Stream\Stream
Guzzle\Http\CachingEntityBody is now GuzzleHttp\Stream\CachingStream
Guzzle\Http\ReadLimitEntityBody is now GuzzleHttp\Stream\LimitStream
Guzzle\Http\IoEmittyinEntityBody has been removed.

Request lifecycle events

Requests previously submitted a large number of requests. The number of events
emitted over the lifecycle of a request has been significantly reduced to make
it easier to understand how to extend the behavior of a request. All events
emitted during the lifecycle of a request now emit a custom
GuzzleHttp\Event\EventInterface object that contains context providing
methods and a way in which to modify the transaction at that specific point in
time (e.g., intercept the request and set a response on the transaction).

request.before_send has been renamed to before and now emits a
GuzzleHttp\Event\BeforeEvent
request.complete has been renamed to complete and now emits a
GuzzleHttp\Event\CompleteEvent.
request.sent has been removed. Use complete.
request.success has been removed. Use complete.
error is now an event that emits a GuzzleHttp\Event\ErrorEvent.
request.exception has been removed. Use error.
request.receive.status_line has been removed.
curl.callback.progress has been removed. Use a custom StreamInterface to
maintain a status update.
curl.callback.write has been removed. Use a custom StreamInterface to
intercept writes.
curl.callback.read has been removed. Use a custom StreamInterface to
intercept reads.

headers is a new event that is emitted after the response headers of a
request have been received before the body of the response is downloaded. This
event emits a GuzzleHttp\Event\HeadersEvent.

You can intercept a request and inject a response using the intercept() event
of a GuzzleHttp\Event\BeforeEvent, GuzzleHttp\Event\CompleteEvent, and
GuzzleHttp\Event\ErrorEvent event.

See: http://docs.guzzlephp.org/en/latest/events.html

Inflection

The Guzzle\Inflection namespace has been removed. This is not a core concern
of Guzzle.

Iterator

The Guzzle\Iterator namespace has been removed.

Guzzle\Iterator\AppendIterator, Guzzle\Iterator\ChunkedIterator, and
Guzzle\Iterator\MethodProxyIterator are nice, but not a core requirement of
Guzzle itself.
Guzzle\Iterator\FilterIterator is no longer needed because an equivalent
class is shipped with PHP 5.4.
Guzzle\Iterator\MapIterator is not really needed when using PHP 5.5 because
it's easier to just wrap an iterator in a generator that maps values.

For a replacement of these iterators, see https://github.com/nikic/iter

Log

The LogPlugin has moved to https://github.com/guzzle/log-subscriber. The
Guzzle\Log namespace has been removed. Guzzle now relies on
Psr\Log\LoggerInterface for all logging. The MessageFormatter class has been
moved to GuzzleHttp\Subscriber\Log\Formatter.

Parser

The Guzzle\Parser namespace has been removed. This was previously used to
make it possible to plug in custom parsers for cookies, messages, URI
templates, and URLs; however, this level of complexity is not needed in Guzzle
so it has been removed.

Cookie: Cookie parsing logic has been moved to
GuzzleHttp\Cookie\SetCookie::fromString.
Message: Message parsing logic for both requests and responses has been moved
to GuzzleHttp\Message\MessageFactory::fromMessage. Message parsing is only
used in debugging or deserializing messages, so it doesn't make sense for
Guzzle as a library to add this level of complexity to parsing messages.
UriTemplate: URI template parsing has been moved to
GuzzleHttp\UriTemplate. The Guzzle library will automatically use the PECL
URI template library if it is installed.
Url: URL parsing is now performed in GuzzleHttp\Url::fromString (previously
it was Guzzle\Http\Url::factory()). If custom URL parsing is necessary,
then developers are free to subclass GuzzleHttp\Url.

Plugin

The Guzzle\Plugin namespace has been renamed to GuzzleHttp\Subscriber.
Several plugins are shipping with the core Guzzle library under this namespace.

GuzzleHttp\Subscriber\Cookie: Replaces the old CookiePlugin. Cookie jar
code has moved to GuzzleHttp\Cookie.
GuzzleHttp\Subscriber\History: Replaces the old HistoryPlugin.
GuzzleHttp\Subscriber\HttpError: Throws errors when a bad HTTP response is
received.
GuzzleHttp\Subscriber\Mock: Replaces the old MockPlugin.
GuzzleHttp\Subscriber\Prepare: Prepares the body of a request just before
sending. This subscriber is attached to all requests by default.
GuzzleHttp\Subscriber\Redirect: Replaces the RedirectPlugin.

The following plugins have been removed (third-parties are free to re-implement
these if needed):

GuzzleHttp\Plugin\Async has been removed.
GuzzleHttp\Plugin\CurlAuth has been removed.
GuzzleHttp\Plugin\ErrorResponse\ErrorResponsePlugin has been removed. This
functionality should instead be implemented with event listeners that occur
after normal response parsing occurs in the guzzle/command package.

The following plugins are not part of the core Guzzle package, but are provided
in separate repositories:

Guzzle\Http\Plugin\BackoffPlugin has been rewritten to be much simpler
to build custom retry policies using simple functions rather than various
chained classes. See: https://github.com/guzzle/retry-subscriber
Guzzle\Http\Plugin\Cache\CachePlugin has moved to
https://github.com/guzzle/cache-subscriber
Guzzle\Http\Plugin\Log\LogPlugin has moved to
https://github.com/guzzle/log-subscriber
Guzzle\Http\Plugin\Md5\Md5Plugin has moved to
https://github.com/guzzle/message-integrity-subscriber
Guzzle\Http\Plugin\Mock\MockPlugin has moved to
GuzzleHttp\Subscriber\MockSubscriber.
Guzzle\Http\Plugin\Oauth\OauthPlugin has moved to
https://github.com/guzzle/oauth-subscriber

Service

The service description layer of Guzzle has moved into two separate packages:

http://github.com/guzzle/command Provides a high level abstraction over web
services by representing web service operations using commands.
http://github.com/guzzle/guzzle-services Provides an implementation of
guzzle/command that provides request serialization and response parsing using
Guzzle service descriptions.

Stream

Stream have moved to a separate package available at
https://github.com/guzzle/streams.

Guzzle\Stream\StreamInterface has been given a large update to cleanly take
on the responsibilities of Guzzle\Http\EntityBody and
Guzzle\Http\EntityBodyInterface now that they have been removed. The number
of methods implemented by the StreamInterface has been drastically reduced to
allow developers to more easily extend and decorate stream behavior.

Removed methods from StreamInterface

getStream and setStream have been removed to better encapsulate streams.
getMetadata and setMetadata have been removed in favor of
GuzzleHttp\Stream\MetadataStreamInterface.
getWrapper, getWrapperData, getStreamType, and getUri have all been
removed. This data is accessible when
using streams that implement GuzzleHttp\Stream\MetadataStreamInterface.
rewind has been removed. Use seek(0) for a similar behavior.

Renamed methods

detachStream has been renamed to detach.
feof has been renamed to eof.
ftell has been renamed to tell.
readLine has moved from an instance method to a static class method of
GuzzleHttp\Stream\Stream.

Metadata streams

GuzzleHttp\Stream\MetadataStreamInterface has been added to denote streams
that contain additional metadata accessible via getMetadata().
GuzzleHttp\Stream\StreamInterface::getMetadata and
GuzzleHttp\Stream\StreamInterface::setMetadata have been removed.

StreamRequestFactory

The entire concept of the StreamRequestFactory has been removed. The way this
was used in Guzzle 3 broke the actual interface of sending streaming requests
(instead of getting back a Response, you got a StreamInterface). Streaming
PHP requests are now implemented through the GuzzleHttp\Adapter\StreamAdapter.

3.6 to 3.7

Deprecations

You can now enable E_USER_DEPRECATED warnings to see if you are using any deprecated methods.:

\Guzzle\Common\Version::$emitWarnings = true;

The following APIs and options have been marked as deprecated:

Marked Guzzle\Http\Message\Request::isResponseBodyRepeatable() as deprecated. Use $request->getResponseBody()->isRepeatable() instead.
Marked Guzzle\Http\Message\Request::canCache() as deprecated. Use Guzzle\Plugin\Cache\DefaultCanCacheStrategy->canCacheRequest() instead.
Marked Guzzle\Http\Message\Request::canCache() as deprecated. Use Guzzle\Plugin\Cache\DefaultCanCacheStrategy->canCacheRequest() instead.
Marked Guzzle\Http\Message\Request::setIsRedirect() as deprecated. Use the HistoryPlugin instead.
Marked Guzzle\Http\Message\Request::isRedirect() as deprecated. Use the HistoryPlugin instead.
Marked Guzzle\Cache\CacheAdapterFactory::factory() as deprecated
Marked Guzzle\Service\Client::enableMagicMethods() as deprecated. Magic methods can no longer be disabled on a Guzzle\Service\Client.
Marked Guzzle\Parser\Url\UrlParser as deprecated. Just use PHP's parse_url() and percent encode your UTF-8.
Marked Guzzle\Common\Collection::inject() as deprecated.
Marked Guzzle\Plugin\CurlAuth\CurlAuthPlugin as deprecated. Use
$client->getConfig()->setPath('request.options/auth', array('user', 'pass', 'Basic|Digest|NTLM|Any')); or
$client->setDefaultOption('auth', array('user', 'pass', 'Basic|Digest|NTLM|Any'));

3.7 introduces request.options as a parameter for a client configuration and as an optional argument to all creational
request methods. When paired with a client's configuration settings, these options allow you to specify default settings
for various aspects of a request. Because these options make other previous configuration options redundant, several
configuration options and methods of a client and AbstractCommand have been deprecated.

Marked Guzzle\Service\Client::getDefaultHeaders() as deprecated. Use $client->getDefaultOption('headers').
Marked Guzzle\Service\Client::setDefaultHeaders() as deprecated. Use $client->setDefaultOption('headers/{header_name}', 'value').
Marked 'request.params' for Guzzle\Http\Client as deprecated. Use $client->setDefaultOption('params/{param_name}', 'value')

Marked 'command.headers', 'command.response_body' and 'command.on_complete' as deprecated for AbstractCommand. These will work through Guzzle 4.0

$command = $client->getCommand('foo', array(
    'command.headers' => array('Test' => '123'),
    'command.response_body' => '/path/to/file'
));

// Should be changed to:

$command = $client->getCommand('foo', array(
    'command.request_options' => array(
        'headers' => array('Test' => '123'),
        'save_as' => '/path/to/file'
    )
));

Interface changes

Additions and changes (you will need to update any implementations or subclasses you may have created):

Added an $options argument to the end of the following methods of Guzzle\Http\ClientInterface:
createRequest, head, delete, put, patch, post, options, prepareRequest
Added an $options argument to the end of Guzzle\Http\Message\Request\RequestFactoryInterface::createRequest()
Added an applyOptions() method to Guzzle\Http\Message\Request\RequestFactoryInterface
Changed Guzzle\Http\ClientInterface::get($uri = null, $headers = null, $body = null) to
Guzzle\Http\ClientInterface::get($uri = null, $headers = null, $options = array()). You can still pass in a
resource, string, or EntityBody into the $options parameter to specify the download location of the response.
Changed Guzzle\Common\Collection::__construct($data) to no longer accepts a null value for $data but a
default array()
Added Guzzle\Stream\StreamInterface::isRepeatable
Made Guzzle\Http\Client::expandTemplate and getUriTemplate protected methods.

The following methods were removed from interfaces. All of these methods are still available in the concrete classes
that implement them, but you should update your code to use alternative methods:

Removed Guzzle\Http\ClientInterface::setDefaultHeaders(). Use $client->getConfig()->setPath('request.options/headers/{header_name}', 'value'). or $client->getConfig()->setPath('request.options/headers', array('header_name' => 'value'))or $client->setDefaultOption('headers/{header_name}', 'value'). or $client->setDefaultOption('headers', array('header_name' => 'value'))`.
Removed Guzzle\Http\ClientInterface::getDefaultHeaders(). Use$client->getConfig()->getPath('request.options/headers')`.
Removed Guzzle\Http\ClientInterface::expandTemplate(). This is an implementation detail.
Removed Guzzle\Http\ClientInterface::setRequestFactory(). This is an implementation detail.
Removed Guzzle\Http\ClientInterface::getCurlMulti(). This is a very specific implementation detail.
Removed Guzzle\Http\Message\RequestInterface::canCache. Use the CachePlugin.
Removed Guzzle\Http\Message\RequestInterface::setIsRedirect. Use the HistoryPlugin.
Removed Guzzle\Http\Message\RequestInterface::isRedirect. Use the HistoryPlugin.

Cache plugin breaking changes

CacheKeyProviderInterface and DefaultCacheKeyProvider are no longer used. All of this logic is handled in a
CacheStorageInterface. These two objects and interface will be removed in a future version.
Always setting X-cache headers on cached responses
Default cache TTLs are now handled by the CacheStorageInterface of a CachePlugin
CacheStorageInterface::cache($key, Response $response, $ttl = null) has changed to cache(RequestInterface $request, Response $response);
CacheStorageInterface::fetch($key) has changed to fetch(RequestInterface $request);
CacheStorageInterface::delete($key) has changed to delete(RequestInterface $request);
Added CacheStorageInterface::purge($url)
DefaultRevalidation::__construct(CacheKeyProviderInterface $cacheKey, CacheStorageInterface $cache, CachePlugin $plugin) has changed to DefaultRevalidation::__construct(CacheStorageInterface $cache, CanCacheStrategyInterface $canCache = null)
Added RevalidationInterface::shouldRevalidate(RequestInterface $request, Response $response)

3.5 to 3.6

Mixed casing of headers are now forced to be a single consistent casing across all values for that header.
Messages internally use a HeaderCollection object to delegate handling case-insensitive header resolution
Removed the whole changedHeader() function system of messages because all header changes now go through addHeader().
For example, setHeader() first removes the header using unset on a HeaderCollection and then calls addHeader().
Keeping the Host header and URL host in sync is now handled by overriding the addHeader method in Request.
Specific header implementations can be created for complex headers. When a message creates a header, it uses a
HeaderFactory which can map specific headers to specific header classes. There is now a Link header and
CacheControl header implementation.
Moved getLinks() from Response to just be used on a Link header object.

If you previously relied on Guzzle\Http\Message\Header::raw(), then you will need to update your code to use the
HeaderInterface (e.g. toArray(), getAll(), etc.).

Interface changes

Removed from interface: Guzzle\Http\ClientInterface::setUriTemplate
Removed from interface: Guzzle\Http\ClientInterface::setCurlMulti()
Removed Guzzle\Http\Message\Request::receivedRequestHeader() and implemented this functionality in
Guzzle\Http\Curl\RequestMediator
Removed the optional $asString parameter from MessageInterface::getHeader(). Just cast the header to a string.
Removed the optional $tryChunkedTransfer option from Guzzle\Http\Message\EntityEnclosingRequestInterface
Removed the $asObjects argument from Guzzle\Http\Message\MessageInterface::getHeaders()

Removed deprecated functions

Removed Guzzle\Parser\ParserRegister::get(). Use getParser()
Removed Guzzle\Parser\ParserRegister::set(). Use registerParser().

Deprecations

The ability to case-insensitively search for header values
Guzzle\Http\Message\Header::hasExactHeader
Guzzle\Http\Message\Header::raw. Use getAll()
Deprecated cache control specific methods on Guzzle\Http\Message\AbstractMessage. Use the CacheControl header object
instead.

Other changes

All response header helper functions return a string rather than mixing Header objects and strings inconsistently
Removed cURL blacklist support. This is no longer necessary now that Expect, Accept, etc. are managed by Guzzle
directly via interfaces
Removed the injecting of a request object onto a response object. The methods to get and set a request still exist
but are a no-op until removed.
Most classes that used to require a Guzzle\Service\Command\CommandInterface typehint now request a
Guzzle\Service\Command\ArrayCommandInterface.
Added Guzzle\Http\Message\RequestInterface::startResponse() to the RequestInterface to handle injecting a response
on a request while the request is still being transferred
Guzzle\Service\Command\CommandInterface now extends from ToArrayInterface and ArrayAccess

3.3 to 3.4

Base URLs of a client now follow the rules of http://tools.ietf.org/html/rfc3986#section-5.2.2 when merging URLs.

3.2 to 3.3

Response::getEtag() quote stripping removed

Guzzle\Http\Message\Response::getEtag() no longer strips quotes around the ETag response header

Removed `Guzzle\Http\Utils`

The Guzzle\Http\Utils class was removed. This class was only used for testing.

Stream wrapper and type

Guzzle\Stream\Stream::getWrapper() and Guzzle\Stream\Stream::getStreamType() are no longer converted to lowercase.

curl.emit_io became emit_io

Emitting IO events from a RequestMediator is now a parameter that must be set in a request's curl options using the
'emit_io' key. This was previously set under a request's parameters using 'curl.emit_io'

3.1 to 3.2

CurlMulti is no longer reused globally

Before 3.2, the same CurlMulti object was reused globally for each client. This can cause issue where plugins added
to a single client can pollute requests dispatched from other clients.

If you still wish to reuse the same CurlMulti object with each client, then you can add a listener to the
ServiceBuilder's service_builder.create_client event to inject a custom CurlMulti object into each client as it is
created.

$multi = new Guzzle\Http\Curl\CurlMulti();
$builder = Guzzle\Service\Builder\ServiceBuilder::factory('/path/to/config.json');
$builder->addListener('service_builder.create_client', function ($event) use ($multi) {
    $event['client']->setCurlMulti($multi);
}
});

No default path

URLs no longer have a default path value of '/' if no path was specified.

Before:

$request = $client->get('http://www.foo.com');
echo $request->getUrl();
// >> http://www.foo.com/

After:

$request = $client->get('http://www.foo.com');
echo $request->getUrl();
// >> http://www.foo.com

Less verbose BadResponseException

The exception message for Guzzle\Http\Exception\BadResponseException no longer contains the full HTTP request and
response information. You can, however, get access to the request and response object by calling getRequest() or
getResponse() on the exception object.

Query parameter aggregation

Multi-valued query parameters are no longer aggregated using a callback function. Guzzle\Http\Query now has a
setAggregator() method that accepts a Guzzle\Http\QueryAggregator\QueryAggregatorInterface object. This object is
responsible for handling the aggregation of multi-valued query string variables into a flattened hash.

2.8 to 3.x

Guzzle\Service\Inspector

Change \Guzzle\Service\Inspector::fromConfig to \Guzzle\Common\Collection::fromConfig

Before

use Guzzle\Service\Inspector;

class YourClient extends \Guzzle\Service\Client
{
    public static function factory($config = array())
    {
        $default = array();
        $required = array('base_url', 'username', 'api_key');
        $config = Inspector::fromConfig($config, $default, $required);

        $client = new self(
            $config->get('base_url'),
            $config->get('username'),
            $config->get('api_key')
        );
        $client->setConfig($config);

        $client->setDescription(ServiceDescription::factory(__DIR__ . DIRECTORY_SEPARATOR . 'client.json'));

        return $client;
    }

After

use Guzzle\Common\Collection;

class YourClient extends \Guzzle\Service\Client
{
    public static function factory($config = array())
    {
        $default = array();
        $required = array('base_url', 'username', 'api_key');
        $config = Collection::fromConfig($config, $default, $required);

        $client = new self(
            $config->get('base_url'),
            $config->get('username'),
            $config->get('api_key')
        );
        $client->setConfig($config);

        $client->setDescription(ServiceDescription::factory(__DIR__ . DIRECTORY_SEPARATOR . 'client.json'));

        return $client;
    }

Convert XML Service Descriptions to JSON

Before

<?xml version="1.0" encoding="UTF-8"?>
<client>
    <commands>
        <!-- Groups -->
        <command name="list_groups" method="GET" uri="groups.json">
            <doc>Get a list of groups</doc>
        </command>
        <command name="search_groups" method="GET" uri='search.json?query="{{query}} type:group"'>
            <doc>Uses a search query to get a list of groups</doc>
            <param name="query" type="string" required="true" />
        </command>
        <command name="create_group" method="POST" uri="groups.json">
            <doc>Create a group</doc>
            <param name="data" type="array" location="body" filters="json_encode" doc="Group JSON"/>
            <param name="Content-Type" location="header" static="application/json"/>
        </command>
        <command name="delete_group" method="DELETE" uri="groups/{{id}}.json">
            <doc>Delete a group by ID</doc>
            <param name="id" type="integer" required="true"/>
        </command>
        <command name="get_group" method="GET" uri="groups/{{id}}.json">
            <param name="id" type="integer" required="true"/>
        </command>
        <command name="update_group" method="PUT" uri="groups/{{id}}.json">
            <doc>Update a group</doc>
            <param name="id" type="integer" required="true"/>
            <param name="data" type="array" location="body" filters="json_encode" doc="Group JSON"/>
            <param name="Content-Type" location="header" static="application/json"/>
        </command>
    </commands>
</client>

After

{
    "name":       "Zendesk REST API v2",
    "apiVersion": "2012-12-31",
    "description":"Provides access to Zendesk views, groups, tickets, ticket fields, and users",
    "operations": {
        "list_groups":  {
            "httpMethod":"GET",
            "uri":       "groups.json",
            "summary":   "Get a list of groups"
        },
        "search_groups":{
            "httpMethod":"GET",
            "uri":       "search.json?query=\"{query} type:group\"",
            "summary":   "Uses a search query to get a list of groups",
            "parameters":{
                "query":{
                    "location":   "uri",
                    "description":"Zendesk Search Query",
                    "type":       "string",
                    "required":   true
                }
            }
        },
        "create_group": {
            "httpMethod":"POST",
            "uri":       "groups.json",
            "summary":   "Create a group",
            "parameters":{
                "data":        {
                    "type":       "array",
                    "location":   "body",
                    "description":"Group JSON",
                    "filters":    "json_encode",
                    "required":   true
                },
                "Content-Type":{
                    "type":    "string",
                    "location":"header",
                    "static":  "application/json"
                }
            }
        },
        "delete_group": {
            "httpMethod":"DELETE",
            "uri":       "groups/{id}.json",
            "summary":   "Delete a group",
            "parameters":{
                "id":{
                    "location":   "uri",
                    "description":"Group to delete by ID",
                    "type":       "integer",
                    "required":   true
                }
            }
        },
        "get_group":    {
            "httpMethod":"GET",
            "uri":       "groups/{id}.json",
            "summary":   "Get a ticket",
            "parameters":{
                "id":{
                    "location":   "uri",
                    "description":"Group to get by ID",
                    "type":       "integer",
                    "required":   true
                }
            }
        },
        "update_group": {
            "httpMethod":"PUT",
            "uri":       "groups/{id}.json",
            "summary":   "Update a group",
            "parameters":{
                "id":          {
                    "location":   "uri",
                    "description":"Group to update by ID",
                    "type":       "integer",
                    "required":   true
                },
                "data":        {
                    "type":       "array",
                    "location":   "body",
                    "description":"Group JSON",
                    "filters":    "json_encode",
                    "required":   true
                },
                "Content-Type":{
                    "type":    "string",
                    "location":"header",
                    "static":  "application/json"
                }
            }
        }
}

Guzzle\Service\Description\ServiceDescription

Commands are now called Operations

Before

use Guzzle\Service\Description\ServiceDescription;

$sd = new ServiceDescription();
$sd->getCommands();     // @returns ApiCommandInterface[]
$sd->hasCommand($name);
$sd->getCommand($name); // @returns ApiCommandInterface|null
$sd->addCommand($command); // @param ApiCommandInterface $command

After

use Guzzle\Service\Description\ServiceDescription;

$sd = new ServiceDescription();
$sd->getOperations();           // @returns OperationInterface[]
$sd->hasOperation($name);
$sd->getOperation($name);       // @returns OperationInterface|null
$sd->addOperation($operation);  // @param OperationInterface $operation

Guzzle\Common\Inflection\Inflector

Namespace is now Guzzle\Inflection\Inflector

Guzzle\Http\Plugin

Namespace is now Guzzle\Plugin. Many other changes occur within this namespace and are detailed in their own sections below.

Guzzle\Http\Plugin\LogPlugin and Guzzle\Common\Log

Now Guzzle\Plugin\Log\LogPlugin and Guzzle\Log respectively.

Before

use Guzzle\Common\Log\ClosureLogAdapter;
use Guzzle\Http\Plugin\LogPlugin;

/** @var \Guzzle\Http\Client */
$client;

// $verbosity is an integer indicating desired message verbosity level
$client->addSubscriber(new LogPlugin(new ClosureLogAdapter(function($m) { echo $m; }, $verbosity = LogPlugin::LOG_VERBOSE);

After

use Guzzle\Log\ClosureLogAdapter;
use Guzzle\Log\MessageFormatter;
use Guzzle\Plugin\Log\LogPlugin;

/** @var \Guzzle\Http\Client */
$client;

// $format is a string indicating desired message format -- @see MessageFormatter
$client->addSubscriber(new LogPlugin(new ClosureLogAdapter(function($m) { echo $m; }, $format = MessageFormatter::DEBUG_FORMAT);

Guzzle\Http\Plugin\CurlAuthPlugin

Now Guzzle\Plugin\CurlAuth\CurlAuthPlugin.

Guzzle\Http\Plugin\ExponentialBackoffPlugin

Now Guzzle\Plugin\Backoff\BackoffPlugin, and other changes.

Before

use Guzzle\Http\Plugin\ExponentialBackoffPlugin;

$backoffPlugin = new ExponentialBackoffPlugin($maxRetries, array_merge(
        ExponentialBackoffPlugin::getDefaultFailureCodes(), array(429)
    ));

$client->addSubscriber($backoffPlugin);

After

use Guzzle\Plugin\Backoff\BackoffPlugin;
use Guzzle\Plugin\Backoff\HttpBackoffStrategy;

// Use convenient factory method instead -- see implementation for ideas of what
// you can do with chaining backoff strategies
$backoffPlugin = BackoffPlugin::getExponentialBackoff($maxRetries, array_merge(
        HttpBackoffStrategy::getDefaultFailureCodes(), array(429)
    ));
$client->addSubscriber($backoffPlugin);

Known Issues

[BUG] Accept-Encoding header behavior changed unintentionally.

(See #217) (Fixed in 09daeb8c666fb44499a0646d655a8ae36456575e)

In version 2.8 setting the Accept-Encoding header would set the CURLOPT_ENCODING option, which permitted cURL to
properly handle gzip/deflate compressed responses from the server. In versions affected by this bug this does not happen.
See issue #217 for a workaround, or use a version containing the fix.

Guzzle Upgrade Guide

5.0 to 6.0

Migrating to middleware

POST Requests

4.x to 5.0

Rewritten Adapter Layer

Removed Fluent Interfaces

Removed functions.php

throwImmediately has been removed

headers event has been removed

Updates to HTTP Messages

3.x to 4.0

Overarching changes:

Batch

Cache

Common

Collection

Events

Emitter

Http

General changes

Client

Messages

Requests with a body

Headers

Responses

Streaming responses

Redirects

EntityBody

Request lifecycle events

Inflection

Iterator

Log

Parser

Plugin

Service

Stream

Removed methods from StreamInterface

Renamed methods

Metadata streams

StreamRequestFactory

3.6 to 3.7

Deprecations

Interface changes

Cache plugin breaking changes

3.5 to 3.6

Interface changes

Removed deprecated functions

Deprecations

Other changes

3.3 to 3.4

3.2 to 3.3

Response::getEtag() quote stripping removed

Removed Guzzle\Http\Utils

Stream wrapper and type

curl.emit_io became emit_io

3.1 to 3.2

CurlMulti is no longer reused globally

No default path

Less verbose BadResponseException

Query parameter aggregation

2.8 to 3.x

Guzzle\Service\Inspector

Convert XML Service Descriptions to JSON

Guzzle\Service\Description\ServiceDescription

Guzzle\Common\Inflection\Inflector

Guzzle\Http\Plugin

Guzzle\Http\Plugin\LogPlugin and Guzzle\Common\Log

Guzzle\Http\Plugin\CurlAuthPlugin

Guzzle\Http\Plugin\ExponentialBackoffPlugin

Known Issues

[BUG] Accept-Encoding header behavior changed unintentionally.

`throwImmediately` has been removed

Removed `Guzzle\Http\Utils`