From 7d5991a96ef8807ed8e0b3249fce32fc83e5bf73 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Dariusz=20J=C4=99drzejczyk?= <2554306+chemicL@users.noreply.github.com> Date: Thu, 11 Jun 2026 11:40:32 +0200 Subject: [PATCH 1/3] Add 2025-11-25 spec version to STDIO transport MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com> --- .../client/transport/StdioClientTransport.java | 7 +++++++ .../server/transport/StdioServerTransportProvider.java | 3 ++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java b/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java index e73e43ef5..49d1b2ee9 100644 --- a/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java +++ b/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java @@ -23,6 +23,7 @@ import io.modelcontextprotocol.spec.McpClientTransport; import io.modelcontextprotocol.spec.McpSchema; import io.modelcontextprotocol.spec.McpSchema.JSONRPCMessage; +import io.modelcontextprotocol.spec.ProtocolVersions; import io.modelcontextprotocol.util.Assert; import org.slf4j.Logger; import org.slf4j.LoggerFactory; @@ -400,4 +401,10 @@ public T unmarshalFrom(Object data, TypeRef typeRef) { return this.jsonMapper.convertValue(data, typeRef); } + @Override + public List protocolVersions() { + return List.of(ProtocolVersions.MCP_2024_11_05, ProtocolVersions.MCP_2025_03_26, + ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25); + } + } diff --git a/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/StdioServerTransportProvider.java b/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/StdioServerTransportProvider.java index 66cc304d6..001ee7b4d 100644 --- a/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/StdioServerTransportProvider.java +++ b/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/StdioServerTransportProvider.java @@ -84,7 +84,8 @@ public StdioServerTransportProvider(McpJsonMapper jsonMapper, InputStream inputS @Override public List protocolVersions() { - return List.of(ProtocolVersions.MCP_2024_11_05); + return List.of(ProtocolVersions.MCP_2024_11_05, ProtocolVersions.MCP_2025_03_26, + ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25); } @Override From f1a58aec97d4a4d0a620e559a315859a276c0d23 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Dariusz=20J=C4=99drzejczyk?= <2554306+chemicL@users.noreply.github.com> Date: Thu, 11 Jun 2026 12:08:10 +0200 Subject: [PATCH 2/3] Unify versions returned MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com> --- .../client/transport/StdioClientTransport.java | 7 ------- .../HttpServletStreamableServerTransportProvider.java | 7 ------- .../server/transport/StdioServerTransportProvider.java | 7 ------- .../spec/McpServerTransportProviderBase.java | 3 ++- .../java/io/modelcontextprotocol/spec/McpTransport.java | 3 ++- 5 files changed, 4 insertions(+), 23 deletions(-) diff --git a/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java b/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java index 49d1b2ee9..e73e43ef5 100644 --- a/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java +++ b/mcp-core/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java @@ -23,7 +23,6 @@ import io.modelcontextprotocol.spec.McpClientTransport; import io.modelcontextprotocol.spec.McpSchema; import io.modelcontextprotocol.spec.McpSchema.JSONRPCMessage; -import io.modelcontextprotocol.spec.ProtocolVersions; import io.modelcontextprotocol.util.Assert; import org.slf4j.Logger; import org.slf4j.LoggerFactory; @@ -401,10 +400,4 @@ public T unmarshalFrom(Object data, TypeRef typeRef) { return this.jsonMapper.convertValue(data, typeRef); } - @Override - public List protocolVersions() { - return List.of(ProtocolVersions.MCP_2024_11_05, ProtocolVersions.MCP_2025_03_26, - ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25); - } - } 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 d956a8726..e6af4fd0f 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 @@ -27,7 +27,6 @@ import io.modelcontextprotocol.spec.McpStreamableServerSession; import io.modelcontextprotocol.spec.McpStreamableServerTransport; import io.modelcontextprotocol.spec.McpStreamableServerTransportProvider; -import io.modelcontextprotocol.spec.ProtocolVersions; import io.modelcontextprotocol.util.Assert; import io.modelcontextprotocol.json.McpJsonDefaults; import io.modelcontextprotocol.json.McpJsonMapper; @@ -166,12 +165,6 @@ private HttpServletStreamableServerTransportProvider(McpJsonMapper jsonMapper, S } - @Override - public List protocolVersions() { - return List.of(ProtocolVersions.MCP_2024_11_05, ProtocolVersions.MCP_2025_03_26, - ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25); - } - @Override public void setSessionFactory(McpStreamableServerSession.Factory sessionFactory) { this.sessionFactory = sessionFactory; diff --git a/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/StdioServerTransportProvider.java b/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/StdioServerTransportProvider.java index 001ee7b4d..045d7e3a9 100644 --- a/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/StdioServerTransportProvider.java +++ b/mcp-core/src/main/java/io/modelcontextprotocol/server/transport/StdioServerTransportProvider.java @@ -22,7 +22,6 @@ import io.modelcontextprotocol.spec.McpServerSession; import io.modelcontextprotocol.spec.McpServerTransport; import io.modelcontextprotocol.spec.McpServerTransportProvider; -import io.modelcontextprotocol.spec.ProtocolVersions; import io.modelcontextprotocol.util.Assert; import io.modelcontextprotocol.json.McpJsonMapper; import org.slf4j.Logger; @@ -82,12 +81,6 @@ public StdioServerTransportProvider(McpJsonMapper jsonMapper, InputStream inputS this.outputStream = outputStream; } - @Override - public List protocolVersions() { - return List.of(ProtocolVersions.MCP_2024_11_05, ProtocolVersions.MCP_2025_03_26, - ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25); - } - @Override public void setSessionFactory(McpServerSession.Factory sessionFactory) { // Create a single session for the stdio connection 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 8d5e0f847..fa1ee055f 100644 --- a/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpServerTransportProviderBase.java +++ b/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpServerTransportProviderBase.java @@ -82,7 +82,8 @@ default void close() { * @return the protocol version as a string */ default List protocolVersions() { - return List.of(ProtocolVersions.MCP_2024_11_05); + return List.of(ProtocolVersions.MCP_2024_11_05, ProtocolVersions.MCP_2025_03_26, + ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25); } } 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 658dc6af5..ab5fa3354 100644 --- a/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpTransport.java +++ b/mcp-core/src/main/java/io/modelcontextprotocol/spec/McpTransport.java @@ -101,7 +101,8 @@ static boolean isPeerClosed(Throwable t) { T unmarshalFrom(Object data, TypeRef typeRef); default List protocolVersions() { - return List.of(ProtocolVersions.MCP_2024_11_05); + return List.of(ProtocolVersions.MCP_2024_11_05, ProtocolVersions.MCP_2025_03_26, + ProtocolVersions.MCP_2025_06_18, ProtocolVersions.MCP_2025_11_25); } } From db7ae5cfb1ee4c697f4b4b31fce305b0cc1bccae Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Dariusz=20J=C4=99drzejczyk?= <2554306+chemicL@users.noreply.github.com> Date: Thu, 11 Jun 2026 12:11:45 +0200 Subject: [PATCH 3/3] Update migration notes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com> --- MIGRATION-2.0.md | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/MIGRATION-2.0.md b/MIGRATION-2.0.md index 70768f222..f2e4e0508 100644 --- a/MIGRATION-2.0.md +++ b/MIGRATION-2.0.md @@ -214,6 +214,18 @@ The deprecated `Builder.customizeRequest(Consumer)` method **Action:** Use `requestBuilder(HttpRequest.Builder)` for static request setup, or `httpRequestCustomizer(McpSyncHttpClientRequestCustomizer)` for per-request customization. +### `protocolVersions()` default now advertises all known versions + +The default implementation of `protocolVersions()` on `McpTransport` and `McpServerTransportProviderBase` previously returned only `["2024-11-05"]`. It now returns all four versions the SDK understands: + +``` +["2024-11-05", "2025-03-26", "2025-06-18", "2025-11-25"] +``` + +**Impact for transport implementors:** If your custom `McpClientTransport` or `McpServerTransportProvider` did not override `protocolVersions()`, it will now advertise all four versions during protocol negotiation instead of just `2024-11-05`. This is the intended upgrade path for most transports, but if you need to restrict your transport to a specific set of versions, override `protocolVersions()` explicitly and return the desired list. + +**Impact for users of built-in transports:** No action is required. `StdioClientTransport`, `StdioServerTransportProvider`, and `HttpServletStreamableServerTransportProvider` all advertise the full version list. + ### SSE transports are deprecated The HTTP+SSE client and server transports (and their supporting validator/exception types) are deprecated in favour of Streamable HTTP — `HttpClientStreamableHttpTransport` on the client, and `HttpServletStreamableServerTransportProvider` on the server. They still work; plan a move to Streamable HTTP.