Add MicronautMcpTransportContext to have access to currently authenticated user, locale, host

gradle/libs.versions.toml

@@ -19,6 +19,7 @@
 micronaut = "4.9.11"
 micronaut-platform = "4.9.3"
 micronaut-docs = "2.0.0"
+micronaut-security = "4.15.0"
 micronaut-serde = "2.15.1"
 micronaut-json-schema = "1.7.1"
 micronaut-logging = "1.7.0"
@@ -33,7 +34,7 @@ micronaut-gradle-plugin = "4.5.4"
 
 [libraries]
 micronaut-core = { module = 'io.micronaut:micronaut-core-bom', version.ref = 'micronaut' }
-
+micronaut-security = { module = 'io.micronaut.security:micronaut-security-bom', version.ref = 'micronaut-security' }
 micronaut-json-schema = { module = 'io.micronaut.jsonschema:micronaut-json-schema-bom', version.ref = 'micronaut-json-schema' }
 micronaut-langchain4j = { module = 'io.micronaut.langchain4j:micronaut-langchain4j-bom', version.ref = 'micronaut-langchain4j' }
 micronaut-serde = { module = 'io.micronaut.serde:micronaut-serde-bom', version.ref = 'micronaut-serde' }

micronaut-mcp-server-java-sdk/build.gradle.kts

@@ -14,6 +14,7 @@ dependencies {
     annotationProcessor(mnJsonSchema.micronaut.json.schema.processor)
     implementation(mnJsonSchema.micronaut.json.schema.annotations)
     implementation(mnJsonSchema.micronaut.json.schema.validation)
+    testImplementation(mnSecurity.micronaut.security)
     api(mnJsonSchema.micronaut.json.schema.utils)
     api(mnValidation.validation)
     compileOnly(mn.micronaut.http.server)

micronaut-mcp-server-java-sdk/src/main/java/io/micronaut/mcp/server/DefaultMcpTransportContextExtractor.java → micronaut-mcp-server-java-sdk/src/main/java/io/micronaut/mcp/server/context/DefaultMcpTransportContextExtractor.java

@@ -13,16 +13,20 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package io.micronaut.mcp.server;
+package io.micronaut.mcp.server.context;
 
 import io.micronaut.core.annotation.Internal;
+import io.micronaut.core.util.LocaleResolver;
+import io.micronaut.http.HttpAttributes;
 import io.micronaut.http.HttpHeaders;
 import io.micronaut.http.HttpRequest;
+import io.micronaut.http.server.util.HttpHostResolver;
 import io.modelcontextprotocol.common.McpTransportContext;
 import io.modelcontextprotocol.server.McpTransportContextExtractor;
 import io.modelcontextprotocol.spec.ProtocolVersions;
 import jakarta.inject.Singleton;
 
+import java.security.Principal;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -32,17 +36,32 @@
 @Internal
 @Singleton
 final class DefaultMcpTransportContextExtractor implements McpTransportContextExtractor<HttpRequest<?>> {
+    private final HttpHostResolver hostResolver;
+    private final LocaleResolver<HttpRequest<?>> localeResolver;
+
+    DefaultMcpTransportContextExtractor(HttpHostResolver hostResolver,
+                                        LocaleResolver<HttpRequest<?>> localeResolver) {
+        this.hostResolver = hostResolver;
+        this.localeResolver = localeResolver;
+    }
+
     @Override
     public McpTransportContext extract(HttpRequest<?> request) {
-        return McpTransportContext.create(metadata(request));
+        return new MicronautMcpTransportContextAdapter(McpTransportContext.create(metadata(request)));
     }
 
     private Map<String, Object> metadata(HttpRequest<?> request) {
-        return metadata(request.getHeaders());
+        Map<String, Object> m = new HashMap<>(metadata(request.getHeaders()));
+        m.put(HttpHeaders.HOST, hostResolver.resolve(request));
+        localeResolver.resolve(request)
+            .ifPresent(locale -> m.put(HttpHeaders.ACCEPT_LANGUAGE, locale));
+        request.getAttribute(HttpAttributes.PRINCIPAL.toString(), Principal.class)
+            .ifPresent(auth -> m.put(HttpAttributes.PRINCIPAL.toString(), auth));
+        return m;
     }
 
     private Map<String, Object> metadata(HttpHeaders headers) {
-        Map<String, Object> metadata = new HashMap<>();
+        Map<String, Object> metadata = new HashMap<>(3);
         metadata.put(io.modelcontextprotocol.spec.HttpHeaders.PROTOCOL_VERSION,
             headers.get(io.modelcontextprotocol.spec.HttpHeaders.PROTOCOL_VERSION, String.class)
                 .orElse(ProtocolVersions.MCP_2025_03_26));

micronaut-mcp-server-java-sdk/src/main/java/io/micronaut/mcp/server/context/MicronautMcpTransportContext.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2017-2025 original authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.micronaut.mcp.server.context;
+
+import io.micronaut.core.annotation.Nullable;
+import io.modelcontextprotocol.common.McpTransportContext;
+
+import java.security.Principal;
+import java.util.Locale;
+
+/**
+ * Extension of {@link McpTransportContext} with convenience methods to access common transport metadata in a Micronaut context.
+ */
+public interface MicronautMcpTransportContext extends McpTransportContext {
+    /**
+     *
+     * @return The Locale of the request, if available
+     */
+    @Nullable
+    Locale locale();
+
+    /**
+     *
+     * @return The server host if available
+     */
+    @Nullable
+    String host();
+
+
+    /**
+     *
+     * @return The authenticated principal if available
+     */
+    @Nullable
+    Principal principal();
+
+    /**
+     *
+     * @return the last event ID if available
+     */
+    @Nullable
+    String lastEventId();
+
+    /**
+     *
+     * @return the session ID if available
+     */
+    @Nullable
+    String sessionId();
+
+    /**
+     *
+     * @return the MCP Protocol version
+     */
+    @Nullable
+    String protocolVersion();
+}

micronaut-mcp-server-java-sdk/src/main/java/io/micronaut/mcp/server/context/MicronautMcpTransportContextAdapter.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2017-2025 original authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.micronaut.mcp.server.context;
+
+import io.micronaut.core.annotation.Internal;
+import io.micronaut.core.annotation.Nullable;
+import io.micronaut.http.HttpAttributes;
+import io.micronaut.http.HttpHeaders;
+import io.modelcontextprotocol.common.McpTransportContext;
+
+import java.security.Principal;
+import java.util.Locale;
+
+@Internal
+final class MicronautMcpTransportContextAdapter implements MicronautMcpTransportContext {
+    private final McpTransportContext delegate;
+
+    MicronautMcpTransportContextAdapter(McpTransportContext context) {
+        this.delegate = context;
+    }
+
+    @Override
+    public Object get(String key) {
+        return delegate.get(key);
+    }
+
+    @Nullable
+    @Override
+    public Locale locale() {
+        Object obj = get(HttpHeaders.ACCEPT_LANGUAGE);
+        if (obj instanceof Locale locale) {
+            return locale;
+        }
+        return null;
+    }
+
+    @Nullable
+    @Override
+    public String host() {
+        return getString(HttpHeaders.HOST);
+    }
+
+    @Nullable
+    @Override
+    public Principal principal() {
+        Object obj = get(HttpAttributes.PRINCIPAL.toString());
+        if (obj instanceof Principal principal) {
+            return principal;
+        }
+        return null;
+    }
+
+    @Nullable
+    @Override
+    public String lastEventId() {
+        return getString(io.modelcontextprotocol.spec.HttpHeaders.LAST_EVENT_ID);
+    }
+
+    @Nullable
+    @Override
+    public String sessionId() {
+        return getString(io.modelcontextprotocol.spec.HttpHeaders.MCP_SESSION_ID);
+    }
+
+    @Nullable
+    @Override
+    public String protocolVersion() {
+        return getString(io.modelcontextprotocol.spec.HttpHeaders.PROTOCOL_VERSION);
+    }
+
+    private String getString(String key) {
+        Object obj = get(key);
+        if (obj instanceof String str) {
+            return str;
+        }
+        return null;
+    }
+}