diff --git a/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/HttpClientStreamableHttpTransport.java b/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/HttpClientStreamableHttpTransport.java
index e56a23f08..ceae846bf 100644
--- a/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/HttpClientStreamableHttpTransport.java
+++ b/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/HttpClientStreamableHttpTransport.java
@@ -679,7 +679,7 @@ public static class Builder {
 		private Duration connectTimeout = Duration.ofSeconds(10);
 
 		private List<String> supportedProtocolVersions = List.of(ProtocolVersions.MCP_2025_03_26,
-				ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25);
+				ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25, ProtocolVersions.MCP_2026_07_28);
 
 		private McpHttpClientTransportAuthorizationErrorHandler authorizationErrorHandler = McpHttpClientTransportAuthorizationErrorHandler.NOOP;
 
diff --git a/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStreamableServerTransportProvider.java b/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStreamableServerTransportProvider.java
index 63e149ac9..db1c3e67b 100644
--- a/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStreamableServerTransportProvider.java
+++ b/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStreamableServerTransportProvider.java
@@ -981,7 +981,7 @@ public void close() {
 	@Override
 	public List<String> protocolVersions() {
 		return List.of(ProtocolVersions.MCP_2025_03_26, ProtocolVersions.MCP_2025_06_18,
-				ProtocolVersions.MCP_2025_11_25);
+				ProtocolVersions.MCP_2025_11_25, ProtocolVersions.MCP_2026_07_28);
 	}
 
 	public static Builder builder() {
diff --git a/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpServerTransportProviderBase.java b/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpServerTransportProviderBase.java
index fa1ee055f..475f27c08 100644
--- a/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpServerTransportProviderBase.java
+++ b/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpServerTransportProviderBase.java
@@ -83,7 +83,7 @@ default void close() {
 	 */
 	default List<String> protocolVersions() {
 		return List.of(ProtocolVersions.MCP_2024_11_05, ProtocolVersions.MCP_2025_03_26,
-				ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25);
+				ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25, ProtocolVersions.MCP_2026_07_28);
 	}
 
 }
diff --git a/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpStatelessServerTransport.java b/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpStatelessServerTransport.java
index ee28f5ff8..33277429c 100644
--- a/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpStatelessServerTransport.java
+++ b/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpStatelessServerTransport.java
@@ -30,7 +30,7 @@ default void close() {
 
 	default List<String> protocolVersions() {
 		return List.of(ProtocolVersions.MCP_2025_03_26, ProtocolVersions.MCP_2025_06_18,
-				ProtocolVersions.MCP_2025_11_25);
+				ProtocolVersions.MCP_2025_11_25, ProtocolVersions.MCP_2026_07_28);
 	}
 
 }
diff --git a/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpTransport.java b/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpTransport.java
index ab5fa3354..37fe4e840 100644
--- a/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpTransport.java
+++ b/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpTransport.java
@@ -102,7 +102,7 @@ static boolean isPeerClosed(Throwable t) {
 
 	default List<String> protocolVersions() {
 		return List.of(ProtocolVersions.MCP_2024_11_05, ProtocolVersions.MCP_2025_03_26,
-				ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25);
+				ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25, ProtocolVersions.MCP_2026_07_28);
 	}
 
 }
diff --git a/mcp-core/src/main/java/io/modelcontextprotocol/spec/ProtocolVersions.java b/mcp-core/src/main/java/io/modelcontextprotocol/spec/ProtocolVersions.java
index d3d34db62..591781c7f 100644
--- a/mcp-core/src/main/java/io/modelcontextprotocol/spec/ProtocolVersions.java
+++ b/mcp-core/src/main/java/io/modelcontextprotocol/spec/ProtocolVersions.java
@@ -26,4 +26,10 @@ public interface ProtocolVersions {
 	 */
 	String MCP_2025_11_25 = "2025-11-25";
 
+	/**
+	 * MCP protocol version for 2026-07-28.
+	 * https://modelcontextprotocol.io/specification/2026-07-28
+	 */
+	String MCP_2026_07_28 = "2026-07-28";
+
 }
diff --git a/mcp-test/src/test/java/io/modelcontextprotocol/common/HttpClientStreamableHttpVersionNegotiationIntegrationTests.java b/mcp-test/src/test/java/io/modelcontextprotocol/common/HttpClientStreamableHttpVersionNegotiationIntegrationTests.java
index 28432316c..0a43ee146 100644
--- a/mcp-test/src/test/java/io/modelcontextprotocol/common/HttpClientStreamableHttpVersionNegotiationIntegrationTests.java
+++ b/mcp-test/src/test/java/io/modelcontextprotocol/common/HttpClientStreamableHttpVersionNegotiationIntegrationTests.java
@@ -106,14 +106,14 @@ void usesLatestVersion() {
 				.hasSize(3)
 				.map(McpTestRequestRecordingServletFilter.Call::headers)
 				.allSatisfy(headers -> assertThat(headers).containsEntry("mcp-protocol-version",
-						ProtocolVersions.MCP_2025_11_25));
+						ProtocolVersions.MCP_2026_07_28));
 
 			assertThat(response).isNotNull();
 			assertThat(response.content()).hasSize(1)
 				.first()
 				.extracting(McpSchema.TextContent.class::cast)
 				.extracting(McpSchema.TextContent::text)
-				.isEqualTo(ProtocolVersions.MCP_2025_11_25);
+				.isEqualTo(ProtocolVersions.MCP_2026_07_28);
 		}
 
 	}
@@ -121,7 +121,7 @@ void usesLatestVersion() {
 	@Test
 	void usesServerSupportedVersion() {
 		var transport = HttpClientStreamableHttpTransport.builder("http://localhost:" + PORT)
-			.supportedProtocolVersions(List.of(ProtocolVersions.MCP_2025_11_25, "2263-03-18"))
+			.supportedProtocolVersions(List.of(ProtocolVersions.MCP_2026_07_28, "2263-03-18"))
 			.build();
 		try (var client = McpClient.sync(transport).build()) {
 			client.initialize();
@@ -137,14 +137,14 @@ void usesServerSupportedVersion() {
 				.hasSize(2)
 				.map(McpTestRequestRecordingServletFilter.Call::headers)
 				.allSatisfy(headers -> assertThat(headers).containsEntry("mcp-protocol-version",
-						ProtocolVersions.MCP_2025_11_25));
+						ProtocolVersions.MCP_2026_07_28));
 
 			assertThat(response).isNotNull();
 			assertThat(response.content()).hasSize(1)
 				.first()
 				.extracting(McpSchema.TextContent.class::cast)
 				.extracting(McpSchema.TextContent::text)
-				.isEqualTo(ProtocolVersions.MCP_2025_11_25);
+				.isEqualTo(ProtocolVersions.MCP_2026_07_28);
 		}
 	}
 
@@ -155,7 +155,7 @@ void clientDoesNotSupportProtocolVersion20241105ByDefault() {
 		// Testing it on the wire would require building a custom transport
 		// We trust the protocolVersions() accessor instead
 		assertThat(transport.protocolVersions()).containsExactly(ProtocolVersions.MCP_2025_03_26,
-				ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25);
+				ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25, ProtocolVersions.MCP_2026_07_28);
 	}
 
 	@Test
diff --git a/mcp-test/src/test/java/io/modelcontextprotocol/server/McpServerProtocolVersionTests.java b/mcp-test/src/test/java/io/modelcontextprotocol/server/McpServerProtocolVersionTests.java
index 3385b3a6e..b36f0e530 100644
--- a/mcp-test/src/test/java/io/modelcontextprotocol/server/McpServerProtocolVersionTests.java
+++ b/mcp-test/src/test/java/io/modelcontextprotocol/server/McpServerProtocolVersionTests.java
@@ -41,7 +41,7 @@ void shouldUseLatestVersionByDefault() {
 
 		String requestId = UUID.randomUUID().toString();
 
-		transportProvider.simulateIncomingMessage(jsonRpcInitializeRequest(requestId, ProtocolVersions.MCP_2025_11_25));
+		transportProvider.simulateIncomingMessage(jsonRpcInitializeRequest(requestId, ProtocolVersions.MCP_2026_07_28));
 
 		McpSchema.JSONRPCMessage response = serverTransport.getLastSentMessage();
 		assertThat(response).isInstanceOf(McpSchema.JSONRPCResponse.class);