feat: Plugins implementation

src/Client/ScheduleClient.php

@@ -32,6 +32,11 @@
 use Temporal\DataConverter\DataConverter;
 use Temporal\DataConverter\DataConverterInterface;
 use Temporal\Internal\Mapper\ScheduleMapper;
+use Temporal\Plugin\ConnectionPluginContext;
+use Temporal\Plugin\ConnectionPluginInterface;
+use Temporal\Plugin\PluginRegistry;
+use Temporal\Plugin\ScheduleClientPluginContext;
+use Temporal\Plugin\ScheduleClientPluginInterface;
 use Temporal\Internal\Marshaller\Mapper\AttributeMapperFactory;
 use Temporal\Internal\Marshaller\Marshaller;
 use Temporal\Internal\Marshaller\MarshallerInterface;
@@ -45,18 +50,41 @@
     private DataConverterInterface $converter;
     private MarshallerInterface $marshaller;
     private ProtoToArrayConverter $protoConverter;
+    private PluginRegistry $pluginRegistry;
 
     public function __construct(
         ServiceClientInterface $serviceClient,
         ?ClientOptions $options = null,
         ?DataConverterInterface $converter = null,
+        ?PluginRegistry $pluginRegistry = null,
     ) {
         $this->clientOptions = $options ?? new ClientOptions();
         $this->converter = $converter ?? DataConverter::createDefault();
+        $this->pluginRegistry = $pluginRegistry ?? new PluginRegistry();
+
+        // Apply connection plugins (before client-level configuration)
+        $connectionContext = new ConnectionPluginContext($serviceClient);
+        foreach ($this->pluginRegistry->getPlugins(ConnectionPluginInterface::class) as $plugin) {
+            $plugin->configureServiceClient($connectionContext);
+        }
+        $serviceClient = $connectionContext->getServiceClient();
+
+        $pluginContext = new ScheduleClientPluginContext(
+            clientOptions: $this->clientOptions,
+            dataConverter: $this->converter,
+        );
+        foreach ($this->pluginRegistry->getPlugins(ScheduleClientPluginInterface::class) as $plugin) {
+            $plugin->configureScheduleClient($pluginContext);
+        }
+        $this->clientOptions = $pluginContext->getClientOptions();
+        if ($pluginContext->getDataConverter() !== null) {
+            $this->converter = $pluginContext->getDataConverter();
+        }
+
         $this->marshaller = new Marshaller(
             new AttributeMapperFactory(new AttributeReader()),
         );
         $this->protoConverter = new ProtoToArrayConverter($this->converter);
 
         // Set Temporal-Namespace metadata
         $context = $serviceClient->getContext();
@@ -71,8 +99,9 @@
         ServiceClientInterface $serviceClient,
         ?ClientOptions $options = null,
         ?DataConverterInterface $converter = null,
+        ?PluginRegistry $pluginRegistry = null,
     ): ScheduleClientInterface {
-        return new self($serviceClient, $options, $converter);
+        return new self($serviceClient, $options, $converter, $pluginRegistry);
     }
 
     public function createSchedule(

src/Client/WorkflowClient.php

@@ -1,3 +1,3 @@
 <?php
 
 /**
@@ -38,6 +38,14 @@
 use Temporal\Interceptor\WorkflowClientCallsInterceptor;
 use Temporal\Internal\Client\ActivityCompletionClient;
 use Temporal\Internal\Client\WorkflowProxy;
+use Temporal\Plugin\ClientPluginContext;
+use Temporal\Plugin\ClientPluginInterface;
+use Temporal\Plugin\CompositePipelineProvider;
+use Temporal\Plugin\ConnectionPluginContext;
+use Temporal\Plugin\ConnectionPluginInterface;
+use Temporal\Plugin\PluginRegistry;
+use Temporal\Plugin\ScheduleClientPluginInterface;
+use Temporal\Plugin\WorkerPluginInterface;
 use Temporal\Internal\Client\WorkflowRun;
 use Temporal\Internal\Client\WorkflowStarter;
 use Temporal\Internal\Client\WorkflowStub;
@@ -63,6 +71,7 @@
     private DataConverterInterface $converter;
     private ?WorkflowStarter $starter = null;
     private WorkflowReader $reader;
+    private PluginRegistry $pluginRegistry;
 
     /** @var Pipeline<WorkflowClientCallsInterceptor, mixed> */
     private Pipeline $interceptorPipeline;
@@ -72,11 +81,39 @@
         ?ClientOptions $options = null,
         ?DataConverterInterface $converter = null,
         ?PipelineProvider $interceptorProvider = null,
+        ?PluginRegistry $pluginRegistry = null,
     ) {
-        $this->interceptorPipeline = ($interceptorProvider ?? new SimplePipelineProvider())
-            ->getPipeline(WorkflowClientCallsInterceptor::class);
+        $this->pluginRegistry = $pluginRegistry ?? new PluginRegistry();
         $this->clientOptions = $options ?? new ClientOptions();
         $this->converter = $converter ?? DataConverter::createDefault();
+
+        // Apply connection plugins (before client-level configuration)
+        $connectionContext = new ConnectionPluginContext($serviceClient);
+        foreach ($this->pluginRegistry->getPlugins(ConnectionPluginInterface::class) as $plugin) {
+            $plugin->configureServiceClient($connectionContext);
+        }
+        $serviceClient = $connectionContext->getServiceClient();
+
+        $pluginContext = new ClientPluginContext(
+            clientOptions: $this->clientOptions,
+            dataConverter: $this->converter,
+        );
+        foreach ($this->pluginRegistry->getPlugins(ClientPluginInterface::class) as $plugin) {
+            $plugin->configureClient($pluginContext);
+        }
+
+        $this->clientOptions = $pluginContext->getClientOptions();
+        if ($pluginContext->getDataConverter() !== null) {
+            $this->converter = $pluginContext->getDataConverter();
+        }
+
+        // Build interceptor pipeline: merge plugin-contributed interceptors with user-provided ones
+        $provider = new CompositePipelineProvider(
+            $pluginContext->getInterceptors(),
+            $interceptorProvider ?? new SimplePipelineProvider(),
+        );
+
+        $this->interceptorPipeline = $provider->getPipeline(WorkflowClientCallsInterceptor::class);
         $this->reader = new WorkflowReader($this->createReader());
 
         // Set Temporal-Namespace metadata
@@ -96,8 +133,29 @@
         ?ClientOptions $options = null,
         ?DataConverterInterface $converter = null,
         ?PipelineProvider $interceptorProvider = null,
+        ?PluginRegistry $pluginRegistry = null,
     ): self {
-        return new self($serviceClient, $options, $converter, $interceptorProvider);
+        return new self($serviceClient, $options, $converter, $interceptorProvider, $pluginRegistry);
+    }
+
+    /**
+     * Get plugins that also implement WorkerPluginInterface for propagation to workers.
+     *
+     * @return list<WorkerPluginInterface>
+     */
+    public function getWorkerPlugins(): array
+    {
+        return $this->pluginRegistry->getPlugins(WorkerPluginInterface::class);
+    }
+
+    /**
+     * Get plugins that also implement ScheduleClientPluginInterface for propagation to schedule clients.
+     *
+     * @return list<ScheduleClientPluginInterface>
+     */
+    public function getScheduleClientPlugins(): array
+    {
+        return $this->pluginRegistry->getPlugins(ScheduleClientPluginInterface::class);
     }
 
     public function getServiceClient(): ServiceClientInterface

src/Interceptor/SimplePipelineProvider.php

@@ -22,14 +22,28 @@ class SimplePipelineProvider implements PipelineProvider
      * @param array<array-key, Interceptor> $interceptors
      */
     public function __construct(
-        private iterable $interceptors = [],
+        private readonly iterable $interceptors = [],
     ) {}
 
+    /**
+     * Create a new provider with additional interceptors prepended.
+     *
+     * @param list<Interceptor> $interceptors Interceptors to prepend before existing ones.
+     */
+    public function withPrependedInterceptors(array $interceptors): self
+    {
+        if ($interceptors === []) {
+            return $this;
+        }
+
+        return new self(\array_merge($interceptors, [...$this->interceptors]));
+    }
+
     public function getPipeline(string $interceptorClass): Pipeline
     {
         return $this->cache[$interceptorClass] ??= Pipeline::prepare(
             \array_filter(
-                $this->interceptors,
+                [...$this->interceptors],
                 static fn(Interceptor $i): bool => $i instanceof $interceptorClass,
             ),
         );

src/Internal/Transport/Router/GetWorkerInfo.php

@@ -18,6 +18,8 @@
 use Temporal\Internal\Declaration\Prototype\WorkflowPrototype;
 use Temporal\Internal\Marshaller\MarshallerInterface;
 use Temporal\Internal\Repository\RepositoryInterface;
+use Temporal\Plugin\PluginInterface;
+use Temporal\Plugin\PluginRegistry;
 use Temporal\Worker\ServiceCredentials;
 use Temporal\Worker\Transport\Command\ServerRequestInterface;
 use Temporal\Worker\WorkerInterface;
@@ -28,6 +30,7 @@ public function __construct(
         private readonly RepositoryInterface $queues,
         private readonly MarshallerInterface $marshaller,
         private readonly ServiceCredentials $credentials,
+        private readonly PluginRegistry $pluginRegistry,
     ) {}
 
     public function handle(ServerRequestInterface $request, array $headers, Deferred $resolver): void
@@ -54,6 +57,10 @@ private function workerToArray(WorkerInterface $worker): array
             'Name' => $activity->getID(),
         ];
 
+        $map = $this->map($this->pluginRegistry->getPlugins(PluginInterface::class), static fn(PluginInterface $plugin): array => [
+            'Name' => $plugin->getName(),
+            'Version' => null,
+        ]);
         return [
             'TaskQueue'  => $worker->getID(),
             'Options'    => $this->marshaller->marshal($worker->getOptions()),
@@ -62,6 +69,7 @@ private function workerToArray(WorkerInterface $worker): array
             // ActivityInfo[]
             'Activities' => $this->map($worker->getActivities(), $activityMap),
             'PhpSdkVersion' => SdkVersion::getSdkVersion(),
+            'Plugins' => $map,
             'Flags' => (object) $this->prepareFlags(),
         ];
     }

src/Plugin/AbstractPlugin.php

@@ -0,0 +1,34 @@
+<?php
+
+/**
+ * This file is part of Temporal package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Temporal\Plugin;
+
+/**
+ * Abstract base class providing no-op defaults for all plugin methods.
+ *
+ * Plugin authors can extend this and override only what they need.
+ */
+abstract class AbstractPlugin implements TemporalPluginInterface
+{
+    use ConnectionPluginTrait;
+    use ClientPluginTrait;
+    use ScheduleClientPluginTrait;
+    use WorkerPluginTrait;
+
+    public function __construct(
+        private readonly string $name,
+    ) {}
+
+    public function getName(): string
+    {
+        return $this->name;
+    }
+}

src/Plugin/ClientPluginContext.php

@@ -0,0 +1,81 @@
+<?php
+
+/**
+ * This file is part of Temporal package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Temporal\Plugin;
+
+use Temporal\Client\ClientOptions;
+use Temporal\DataConverter\DataConverterInterface;
+use Temporal\Internal\Interceptor\Interceptor;
+
+/**
+ * Builder-style configuration context for workflow client plugins.
+ *
+ * Plugins modify this builder in {@see ClientPluginInterface::configureClient()}.
+ * Uses a fluent API similar to Java SDK's Options.Builder pattern.
+ */
+final class ClientPluginContext
+{
+    /** @var list<Interceptor> */
+    private array $interceptors = [];
+
+    public function __construct(
+        private ClientOptions $clientOptions,
+        private ?DataConverterInterface $dataConverter = null,
+    ) {}
+
+    public function getClientOptions(): ClientOptions
+    {
+        return $this->clientOptions;
+    }
+
+    public function setClientOptions(ClientOptions $clientOptions): self
+    {
+        $this->clientOptions = $clientOptions;
+        return $this;
+    }
+
+    public function getDataConverter(): ?DataConverterInterface
+    {
+        return $this->dataConverter;
+    }
+
+    public function setDataConverter(?DataConverterInterface $dataConverter): self
+    {
+        $this->dataConverter = $dataConverter;
+        return $this;
+    }
+
+    /**
+     * @return list<Interceptor>
+     */
+    public function getInterceptors(): array
+    {
+        return $this->interceptors;
+    }
+
+    /**
+     * @param list<Interceptor> $interceptors
+     */
+    public function setInterceptors(array $interceptors): self
+    {
+        $this->interceptors = $interceptors;
+        return $this;
+    }
+
+    /**
+     * Add an interceptor to the client pipeline.
+     */
+    public function addInterceptor(Interceptor $interceptor): self
+    {
+        $this->interceptors[] = $interceptor;
+        return $this;
+    }
+}

src/Plugin/ClientPluginInterface.php

@@ -0,0 +1,30 @@
+<?php
+
+/**
+ * This file is part of Temporal package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Temporal\Plugin;
+
+/**
+ * Plugin interface for configuring Temporal Clients.
+ *
+ * Plugins that implement either {@see ScheduleClientPluginInterface} and {@see ClientPluginInterface}
+ * are automatically propagated from the service stubs to the schedule client.
+ *
+ * Configuration methods are called in registration order (first registered = first called).
+ */
+interface ClientPluginInterface extends PluginInterface
+{
+    /**
+     * Modify client configuration before the client is created.
+     *
+     * Called in registration order (first plugin registered = first called).
+     */
+    public function configureClient(ClientPluginContext $context): void;
+}

src/Plugin/ClientPluginTrait.php

@@ -0,0 +1,25 @@
+<?php
+
+/**
+ * This file is part of Temporal package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Temporal\Plugin;
+
+/**
+ * No-op defaults for {@see ClientPluginInterface}.
+ *
+ * @implements ClientPluginInterface
+ */
+trait ClientPluginTrait
+{
+    public function configureClient(ClientPluginContext $context): void
+    {
+        // no-op
+    }
+}