diff --git a/src/Client.php b/src/Client.php
index 8bf745f..4ca2ee8 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -79,11 +79,24 @@ public function check_license( $license = '' ) {
 		/**
 		 * Fetch available updates from the remote API.
 		 *
+		 * Uses a short-lived site transient cache to avoid redundant HTTP calls
+		 * when WordPress sets the update_plugins transient multiple times.
+		 *
 		 * @since 1.1
 		 *
+		 * @param int $cache_period Cache duration in seconds. Pass 0 to skip caching.
 		 * @return array|WP_Error Response data or WP_Error on failure.
 		 */
-		public function updates() {
+		public function updates( $cache_period = 600 ) {
+			if ( $cache_period > 0 ) {
+				$cache_key = $this->integration->get_updates_cache_key();
+				$cached    = get_site_transient( $cache_key );
+
+				if ( false !== $cached ) {
+					return $cached;
+				}
+			}
+
 			$args = [];
 			if ( $this->integration->license_enabled ) {
 				$license = $this->integration->get_license_code();
@@ -92,17 +105,36 @@ public function updates() {
 				}
 			}
 
-			return $this->request( 'updates', $args );
+			$response = $this->request( 'updates', $args );
+
+			if ( $cache_period > 0 && ! is_wp_error( $response ) ) {
+				set_site_transient( $cache_key, $response, $cache_period );
+			}
+
+			return $response;
 		}
 
 		/**
 		 * Fetch plugin details from the remote API.
 		 *
+		 * Uses a short-lived site transient cache to avoid redundant HTTP calls
+		 * from plugins_api and the license admin page.
+		 *
 		 * @since 1.1
 		 *
+		 * @param int $cache_period Cache duration in seconds. Pass 0 to skip caching.
 		 * @return array|WP_Error Response data or WP_Error on failure.
 		 */
-		public function details() {
+		public function details( $cache_period = 600 ) {
+			if ( $cache_period > 0 ) {
+				$cache_key = $this->integration->get_details_cache_key();
+				$cached    = get_site_transient( $cache_key );
+
+				if ( false !== $cached ) {
+					return $cached;
+				}
+			}
+
 			$args = [];
 			if ( $this->integration->license_enabled ) {
 				$license = $this->integration->get_license_code();
@@ -111,7 +143,13 @@ public function details() {
 				}
 			}
 
-			return $this->request( 'details', $args );
+			$response = $this->request( 'details', $args );
+
+			if ( $cache_period > 0 && ! is_wp_error( $response ) ) {
+				set_site_transient( $cache_key, $response, $cache_period );
+			}
+
+			return $response;
 		}
 
 		/**
diff --git a/src/Integration.php b/src/Integration.php
index d05f462..2e0248b 100644
--- a/src/Integration.php
+++ b/src/Integration.php
@@ -244,6 +244,28 @@ public function get_license_data_key() {
 			return "{$this->license_name}_data";
 		}
 
+		/**
+		 * Retrieves the transient key for caching updates API responses.
+		 *
+		 * @since 1.3
+		 *
+		 * @return string
+		 */
+		public function get_updates_cache_key() {
+			return "{$this->license_name}_updates_cache";
+		}
+
+		/**
+		 * Retrieves the transient key for caching details API responses.
+		 *
+		 * @since 1.3
+		 *
+		 * @return string
+		 */
+		public function get_details_cache_key() {
+			return "{$this->license_name}_details_cache";
+		}
+
 
 		/**
 		 * Get license status.
@@ -353,6 +375,8 @@ public function is_license_active() {
 		 * @return void
 		 */
 		public function refresh_updates_transient() {
+			delete_site_transient( $this->get_updates_cache_key() );
+			delete_site_transient( $this->get_details_cache_key() );
 			set_site_transient( 'update_plugins', get_site_transient( 'update_plugins' ) );
 		}
 
@@ -363,6 +387,9 @@ public function refresh_updates_transient() {
 		 * @return void
 		 */
 		public function clear_updates_transient() {
+			delete_site_transient( $this->get_updates_cache_key() );
+			delete_site_transient( $this->get_details_cache_key() );
+
 			$transient = get_site_transient( 'update_plugins' );
 
 			// Initialize transient if it doesn't exist
diff --git a/src/Updater.php b/src/Updater.php
index c22136f..b4b0987 100644
--- a/src/Updater.php
+++ b/src/Updater.php
@@ -224,9 +224,9 @@ public function upgrader_process_complete( $upgrader, $args ) {
 				include_once ABSPATH . 'wp-admin/includes/plugin.php';
 				$plugin = get_plugin_data( WP_PLUGIN_DIR . '/' . $this->integration->product_file );
 
-				$this->integration->clear_updates_transient();
-
 				$this->integration->product_version = $plugin['Version'];
+
+				$this->integration->clear_updates_transient();
 				$this->integration->client->ping();
 			}
 		}
diff --git a/tests/ClientApiRequestTest.php b/tests/ClientApiRequestTest.php
index 3452053..db9a531 100644
--- a/tests/ClientApiRequestTest.php
+++ b/tests/ClientApiRequestTest.php
@@ -7,7 +7,7 @@
 class ClientApiRequestTest extends TestCase {
 
 	/**
-	 * Stub the common WP functions used by Client::request().
+	 * Stub the common WP functions used by Client::request() and updates() cache.
 	 */
 	private function stub_api_dependencies(): void {
 		Functions\when( 'esc_url' )->returnArg();
@@ -17,6 +17,21 @@ private function stub_api_dependencies(): void {
 		Functions\when( 'add_query_arg' )->alias( function ( $args, $url ) {
 			return $url . '?' . http_build_query( $args );
 		} );
+		Functions\when( 'get_site_transient' )->justReturn( false );
+		Functions\when( 'set_site_transient' )->justReturn( true );
+	}
+
+	/**
+	 * Stub only the HTTP-layer WP functions (no cache stubs).
+	 */
+	private function stub_http_dependencies(): void {
+		Functions\when( 'esc_url' )->returnArg();
+		Functions\when( 'site_url' )->justReturn( 'https://example.com' );
+		Functions\when( 'get_locale' )->justReturn( 'en_US' );
+		Functions\when( 'get_bloginfo' )->justReturn( '6.4' );
+		Functions\when( 'add_query_arg' )->alias( function ( $args, $url ) {
+			return $url . '?' . http_build_query( $args );
+		} );
 	}
 
 	/** @test */
@@ -239,4 +254,232 @@ public function details_returns_plugin_details() {
 		$this->assertIsArray( $result );
 		$this->assertArrayHasKey( 'details', $result );
 	}
+
+	/** @test */
+	public function updates_returns_cached_response_without_api_call() {
+		$integration = $this->create_integration();
+
+		$cached_response = $this->load_fixture( 'updates-available.json' );
+
+		Functions\expect( 'get_site_transient' )
+			->once()
+			->with( $integration->get_updates_cache_key() )
+			->andReturn( $cached_response );
+
+		Functions\expect( 'wp_remote_request' )->never();
+
+		$result = $integration->client->updates();
+
+		$this->assertIsArray( $result );
+		$this->assertSame( '1.3.0', $result['updates']['new_version'] );
+	}
+
+	/** @test */
+	public function updates_caches_successful_api_response() {
+		$integration = $this->create_integration();
+		$this->stub_http_dependencies();
+
+		$fixture   = $this->load_fixture_raw( 'updates-available.json' );
+		$cache_key = $integration->get_updates_cache_key();
+
+		$stored = null;
+
+		Functions\expect( 'get_site_transient' )
+			->once()
+			->with( $cache_key )
+			->andReturn( false );
+
+		Functions\expect( 'wp_remote_request' )->once()->andReturn( [] );
+		Functions\expect( 'wp_remote_retrieve_response_code' )->once()->andReturn( 200 );
+		Functions\expect( 'wp_remote_retrieve_body' )->once()->andReturn( $fixture );
+
+		Functions\expect( 'set_site_transient' )
+			->once()
+			->with(
+				$cache_key,
+				\Mockery::on( function ( $value ) use ( &$stored ) {
+					$stored = $value;
+					return is_array( $value ) && ! empty( $value['updates'] );
+				} ),
+				600
+			)
+			->andReturn( true );
+
+		$result = $integration->client->updates();
+
+		$this->assertIsArray( $result );
+		$this->assertNotNull( $stored );
+		$this->assertArrayHasKey( 'updates', $stored );
+	}
+
+	/** @test */
+	public function updates_does_not_cache_wp_error_response() {
+		$integration = $this->create_integration();
+		$this->stub_http_dependencies();
+
+		$cache_key = $integration->get_updates_cache_key();
+
+		Functions\expect( 'get_site_transient' )
+			->once()
+			->with( $cache_key )
+			->andReturn( false );
+
+		Functions\expect( 'wp_remote_request' )
+			->once()
+			->andReturn( new WP_Error( 'http_error', 'Timeout' ) );
+
+		Functions\expect( 'set_site_transient' )->never();
+
+		$result = $integration->client->updates();
+
+		$this->assertInstanceOf( WP_Error::class, $result );
+	}
+
+	/** @test */
+	public function updates_skips_cache_when_period_is_zero() {
+		$integration = $this->create_integration();
+		$this->stub_http_dependencies();
+
+		$fixture = $this->load_fixture_raw( 'updates-available.json' );
+
+		Functions\expect( 'get_site_transient' )->never();
+		Functions\expect( 'set_site_transient' )->never();
+
+		Functions\expect( 'wp_remote_request' )->once()->andReturn( [] );
+		Functions\expect( 'wp_remote_retrieve_response_code' )->once()->andReturn( 200 );
+		Functions\expect( 'wp_remote_retrieve_body' )->once()->andReturn( $fixture );
+
+		$result = $integration->client->updates( 0 );
+
+		$this->assertIsArray( $result );
+		$this->assertSame( '1.3.0', $result['updates']['new_version'] );
+	}
+
+	/** @test */
+	public function updates_uses_custom_cache_period() {
+		$integration = $this->create_integration();
+		$this->stub_http_dependencies();
+
+		$fixture   = $this->load_fixture_raw( 'updates-available.json' );
+		$cache_key = $integration->get_updates_cache_key();
+
+		Functions\expect( 'get_site_transient' )
+			->once()
+			->with( $cache_key )
+			->andReturn( false );
+
+		Functions\expect( 'wp_remote_request' )->once()->andReturn( [] );
+		Functions\expect( 'wp_remote_retrieve_response_code' )->once()->andReturn( 200 );
+		Functions\expect( 'wp_remote_retrieve_body' )->once()->andReturn( $fixture );
+
+		Functions\expect( 'set_site_transient' )
+			->once()
+			->with( $cache_key, \Mockery::type( 'array' ), 300 )
+			->andReturn( true );
+
+		$result = $integration->client->updates( 300 );
+
+		$this->assertIsArray( $result );
+		$this->assertSame( '1.3.0', $result['updates']['new_version'] );
+	}
+
+	/** @test */
+	public function details_returns_cached_response_without_api_call() {
+		$integration = $this->create_integration();
+
+		$cached_response = $this->load_fixture( 'details-success.json' );
+
+		Functions\expect( 'get_site_transient' )
+			->once()
+			->with( $integration->get_details_cache_key() )
+			->andReturn( $cached_response );
+
+		Functions\expect( 'wp_remote_request' )->never();
+
+		$result = $integration->client->details();
+
+		$this->assertIsArray( $result );
+		$this->assertArrayHasKey( 'details', $result );
+	}
+
+	/** @test */
+	public function details_caches_successful_api_response() {
+		$integration = $this->create_integration();
+		$this->stub_http_dependencies();
+
+		$fixture   = $this->load_fixture_raw( 'details-success.json' );
+		$cache_key = $integration->get_details_cache_key();
+
+		$stored = null;
+
+		Functions\expect( 'get_site_transient' )
+			->once()
+			->with( $cache_key )
+			->andReturn( false );
+
+		Functions\expect( 'wp_remote_request' )->once()->andReturn( [] );
+		Functions\expect( 'wp_remote_retrieve_response_code' )->once()->andReturn( 200 );
+		Functions\expect( 'wp_remote_retrieve_body' )->once()->andReturn( $fixture );
+
+		Functions\expect( 'set_site_transient' )
+			->once()
+			->with(
+				$cache_key,
+				\Mockery::on( function ( $value ) use ( &$stored ) {
+					$stored = $value;
+					return is_array( $value ) && ! empty( $value['details'] );
+				} ),
+				600
+			)
+			->andReturn( true );
+
+		$result = $integration->client->details();
+
+		$this->assertIsArray( $result );
+		$this->assertNotNull( $stored );
+		$this->assertArrayHasKey( 'details', $stored );
+	}
+
+	/** @test */
+	public function details_does_not_cache_wp_error_response() {
+		$integration = $this->create_integration();
+		$this->stub_http_dependencies();
+
+		$cache_key = $integration->get_details_cache_key();
+
+		Functions\expect( 'get_site_transient' )
+			->once()
+			->with( $cache_key )
+			->andReturn( false );
+
+		Functions\expect( 'wp_remote_request' )
+			->once()
+			->andReturn( new WP_Error( 'http_error', 'Timeout' ) );
+
+		Functions\expect( 'set_site_transient' )->never();
+
+		$result = $integration->client->details();
+
+		$this->assertInstanceOf( WP_Error::class, $result );
+	}
+
+	/** @test */
+	public function details_skips_cache_when_period_is_zero() {
+		$integration = $this->create_integration();
+		$this->stub_http_dependencies();
+
+		$fixture = $this->load_fixture_raw( 'details-success.json' );
+
+		Functions\expect( 'get_site_transient' )->never();
+		Functions\expect( 'set_site_transient' )->never();
+
+		Functions\expect( 'wp_remote_request' )->once()->andReturn( [] );
+		Functions\expect( 'wp_remote_retrieve_response_code' )->once()->andReturn( 200 );
+		Functions\expect( 'wp_remote_retrieve_body' )->once()->andReturn( $fixture );
+
+		$result = $integration->client->details( 0 );
+
+		$this->assertIsArray( $result );
+		$this->assertArrayHasKey( 'details', $result );
+	}
 }
diff --git a/tests/IntegrationTransientTest.php b/tests/IntegrationTransientTest.php
index e9bb2b4..8e7a008 100644
--- a/tests/IntegrationTransientTest.php
+++ b/tests/IntegrationTransientTest.php
@@ -23,6 +23,8 @@ public function moves_plugin_from_response_to_no_update() {
 
 		$saved = null;
 
+		Functions\when( 'delete_site_transient' )->justReturn( true );
+
 		Functions\expect( 'get_site_transient' )
 			->once()
 			->with( 'update_plugins' )
@@ -53,6 +55,8 @@ public function creates_no_update_entry_when_plugin_not_in_response() {
 
 		$saved = null;
 
+		Functions\when( 'delete_site_transient' )->justReturn( true );
+
 		Functions\expect( 'get_site_transient' )
 			->once()
 			->with( 'update_plugins' )
@@ -80,6 +84,8 @@ public function initializes_transient_when_false() {
 
 		$saved = null;
 
+		Functions\when( 'delete_site_transient' )->justReturn( true );
+
 		Functions\expect( 'get_site_transient' )
 			->once()
 			->with( 'update_plugins' )
@@ -110,6 +116,8 @@ public function initializes_no_update_array_when_missing() {
 
 		$saved = null;
 
+		Functions\when( 'delete_site_transient' )->justReturn( true );
+
 		Functions\expect( 'get_site_transient' )
 			->once()
 			->with( 'update_plugins' )
@@ -127,4 +135,66 @@ public function initializes_no_update_array_when_missing() {
 		$this->assertIsArray( $saved->no_update );
 		$this->assertArrayHasKey( 'my-plugin/my-plugin.php', $saved->no_update );
 	}
+
+	/** @test */
+	public function clear_updates_transient_deletes_caches() {
+		$integration = $this->create_integration();
+
+		$transient            = new \stdClass();
+		$transient->response  = [];
+		$transient->no_update = [];
+		$transient->checked   = [];
+
+		$deleted_keys = [];
+
+		Functions\expect( 'delete_site_transient' )
+			->twice()
+			->with( Mockery::on( function ( $key ) use ( &$deleted_keys ) {
+				$deleted_keys[] = $key;
+				return true;
+			} ) );
+
+		Functions\expect( 'get_site_transient' )
+			->once()
+			->with( 'update_plugins' )
+			->andReturn( $transient );
+
+		Functions\expect( 'set_site_transient' )
+			->once();
+
+		$integration->clear_updates_transient();
+
+		$this->assertContains( $integration->get_updates_cache_key(), $deleted_keys );
+		$this->assertContains( $integration->get_details_cache_key(), $deleted_keys );
+	}
+
+	/** @test */
+	public function refresh_updates_transient_deletes_caches() {
+		$integration = $this->create_integration();
+
+		$transient = new \stdClass();
+
+		$deleted_keys = [];
+
+		Functions\expect( 'delete_site_transient' )
+			->twice()
+			->with( Mockery::on( function ( $key ) use ( &$deleted_keys ) {
+				$deleted_keys[] = $key;
+				return true;
+			} ) );
+
+		Functions\expect( 'get_site_transient' )
+			->once()
+			->with( 'update_plugins' )
+			->andReturn( $transient );
+
+		Functions\expect( 'set_site_transient' )
+			->once()
+			->with( 'update_plugins', $transient );
+
+		$integration->refresh_updates_transient();
+
+		$this->assertContains( $integration->get_updates_cache_key(), $deleted_keys );
+		$this->assertContains( $integration->get_details_cache_key(), $deleted_keys );
+	}
 }
diff --git a/tests/UpdaterPreSetTransientTest.php b/tests/UpdaterPreSetTransientTest.php
index ecad74a..e76abe0 100644
--- a/tests/UpdaterPreSetTransientTest.php
+++ b/tests/UpdaterPreSetTransientTest.php
@@ -23,6 +23,9 @@ private function stub_api_dependencies(): void {
 	/**
 	 * Helper: create an Updater with its Integration and stub an API response.
 	 *
+	 * Stubs cache as a miss (get_site_transient returns false) so the API call
+	 * proceeds, and accepts the set_site_transient call to store the cache.
+	 *
 	 * @param string|null $fixture_name Fixture file name or null for WP_Error.
 	 * @param int         $status_code  HTTP status code.
 	 * @return Updater
@@ -31,6 +34,9 @@ private function create_updater_with_api_response( ?string $fixture_name, int $s
 		$integration = $this->create_integration();
 		$this->stub_api_dependencies();
 
+		Functions\when( 'get_site_transient' )->justReturn( false );
+		Functions\when( 'set_site_transient' )->justReturn( true );
+
 		if ( null === $fixture_name ) {
 			Functions\expect( 'wp_remote_request' )
 				->once()
@@ -102,6 +108,9 @@ public function adds_to_no_update_when_version_is_same() {
 		$integration->product_version = '1.3.0'; // Same as fixture.
 		$this->stub_api_dependencies();
 
+		Functions\when( 'get_site_transient' )->justReturn( false );
+		Functions\when( 'set_site_transient' )->justReturn( true );
+
 		$fixture = $this->load_fixture_raw( 'updates-available.json' );
 
 		Functions\expect( 'wp_remote_request' )->once()->andReturn( [] );
@@ -122,6 +131,9 @@ public function adds_to_no_update_when_version_is_lower() {
 		$integration->product_version = '2.0.0'; // Higher than fixture's 1.3.0.
 		$this->stub_api_dependencies();
 
+		Functions\when( 'get_site_transient' )->justReturn( false );
+		Functions\when( 'set_site_transient' )->justReturn( true );
+
 		$fixture = $this->load_fixture_raw( 'updates-available.json' );
 
 		Functions\expect( 'wp_remote_request' )->once()->andReturn( [] );
@@ -142,6 +154,9 @@ public function moves_existing_response_to_no_update_when_not_newer() {
 		$integration->product_version = '1.3.0'; // Same as fixture.
 		$this->stub_api_dependencies();
 
+		Functions\when( 'get_site_transient' )->justReturn( false );
+		Functions\when( 'set_site_transient' )->justReturn( true );
+
 		$fixture = $this->load_fixture_raw( 'updates-available.json' );
 
 		Functions\expect( 'wp_remote_request' )->once()->andReturn( [] );
@@ -181,4 +196,5 @@ public function does_nothing_when_updates_key_missing() {
 		$this->assertEmpty( $result->response );
 		$this->assertEmpty( $result->no_update );
 	}
+
 }
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 793e638..1a390fb 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -15,6 +15,10 @@
 	define( 'WP_PLUGIN_DIR', ABSPATH . 'wp-content/plugins' );
 }
 
+if ( ! defined( 'MINUTE_IN_SECONDS' ) ) {
+	define( 'MINUTE_IN_SECONDS', 60 );
+}
+
 // Minimal WP_Error stub so source files can reference the class.
 if ( ! class_exists( 'WP_Error' ) ) {
 	class WP_Error {