feat: enable MCP sampling support

com.microsoft.copilot.eclipse.core.test/src/com/microsoft/copilot/eclipse/core/chat/ChatEventsManagerTests.java

@@ -0,0 +1,57 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+package com.microsoft.copilot.eclipse.core.chat;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.List;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import com.microsoft.copilot.eclipse.core.lsp.protocol.McpSamplingConfig;
+
+class ChatEventsManagerTests {
+
+  private ChatEventsManager chatEventsManager;
+
+  @BeforeEach
+  void setUp() {
+    chatEventsManager = new ChatEventsManager();
+  }
+
+  @Test
+  void getMcpSamplingConfig_returnsDefaultConfigWhenNoProviderRegistered() {
+    McpSamplingConfig config = chatEventsManager.getMcpSamplingConfig("test-server");
+
+    assertFalse(config.alwaysAllow());
+    assertFalse(config.alwaysDeny());
+    assertEquals(List.of(), config.allowedModels());
+  }
+
+  @Test
+  void getMcpSamplingConfig_delegatesToRegisteredProvider() {
+    McpSamplingConfigProvider provider = mock(McpSamplingConfigProvider.class);
+    McpSamplingConfig expected = new McpSamplingConfig(true, false, List.of());
+    when(provider.getMcpSamplingConfig("test-server")).thenReturn(expected);
+
+    chatEventsManager.registerMcpSamplingConfigProvider(provider);
+
+    assertEquals(expected, chatEventsManager.getMcpSamplingConfig("test-server"));
+  }
+
+  @Test
+  void getMcpSamplingConfig_fallsBackToDefaultAfterUnregister() {
+    McpSamplingConfigProvider provider = mock(McpSamplingConfigProvider.class);
+    chatEventsManager.registerMcpSamplingConfigProvider(provider);
+    chatEventsManager.unregisterMcpSamplingConfigProvider(provider);
+
+    McpSamplingConfig config = chatEventsManager.getMcpSamplingConfig("test-server");
+
+    assertFalse(config.alwaysAllow());
+  }
+}

com.microsoft.copilot.eclipse.core.test/src/com/microsoft/copilot/eclipse/core/lsp/CopilotLanguageClientTests.java

@@ -13,6 +13,7 @@
 import static org.mockito.Mockito.when;
 
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CountDownLatch;
@@ -37,13 +38,16 @@
 
 import com.microsoft.copilot.eclipse.core.CopilotCore;
 import com.microsoft.copilot.eclipse.core.FeatureFlags;
+import com.microsoft.copilot.eclipse.core.chat.ChatEventsManager;
 import com.microsoft.copilot.eclipse.core.chat.service.IChatServiceManager;
 import com.microsoft.copilot.eclipse.core.chat.service.IReferencedFileService;
 import com.microsoft.copilot.eclipse.core.events.CopilotEventConstants;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.ConversationCapabilities;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.ConversationContextParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.CurrentEditorContext;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.DidChangeFeatureFlagsParams;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.McpSamplingConfig;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.ReadMcpSamplingConfigParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.policy.DidChangePolicyParams;
 import com.microsoft.copilot.eclipse.core.utils.FileUtils;
 
@@ -61,6 +65,9 @@ class CopilotLanguageClientTests {
   @Mock
   private IReferencedFileService fileService;
 
+  @Mock
+  private ChatEventsManager chatEventsManager;
+
   @BeforeEach
   void setUp() {
     client = new CopilotLanguageClient();
@@ -145,6 +152,39 @@ void testOnDidChangeFeatureFlagsWithEmptyFeatureFlags() {
     }
   }
 
+  @Test
+  void testReadMcpSamplingConfig_requiresConfirmationAndAllowsAllModels() throws Exception {
+    McpSamplingConfig expected = new McpSamplingConfig(false, false, List.of());
+
+    try (MockedStatic<CopilotCore> copilotCoreMock = Mockito.mockStatic(CopilotCore.class)) {
+      copilotCoreMock.when(CopilotCore::getPlugin).thenReturn(plugin);
+      when(plugin.getChatEventsManager()).thenReturn(chatEventsManager);
+      when(chatEventsManager.getMcpSamplingConfig("test-server")).thenReturn(expected);
+
+      Object[] result = client.readMcpSamplingConfig(new ReadMcpSamplingConfigParams("test-server")).get();
+
+      assertEquals(2, result.length);
+      assertEquals(expected, result[0]);
+      assertNull(result[1]);
+    }
+  }
+
+  @Test
+  void testReadMcpSamplingConfig_reflectsPersistedAlwaysAllowDecision() throws Exception {
+    McpSamplingConfig approved = new McpSamplingConfig(true, false, List.of());
+
+    try (MockedStatic<CopilotCore> copilotCoreMock = Mockito.mockStatic(CopilotCore.class)) {
+      copilotCoreMock.when(CopilotCore::getPlugin).thenReturn(plugin);
+      when(plugin.getChatEventsManager()).thenReturn(chatEventsManager);
+      when(chatEventsManager.getMcpSamplingConfig("test-server")).thenReturn(approved);
+
+      Object[] result = client.readMcpSamplingConfig(new ReadMcpSamplingConfigParams("test-server")).get();
+
+      assertEquals(approved, result[0]);
+      assertTrue(((McpSamplingConfig) result[0]).alwaysAllow());
+    }
+  }
+
   @Test
   void testOnDidChangePolicy_publishesAutoModelPolicyEventOnlyWhenValueChanges() throws InterruptedException {
     IEventBroker eventBroker = EclipseContextFactory

com.microsoft.copilot.eclipse.core.test/src/com/microsoft/copilot/eclipse/core/lsp/LsStreamConnectionProviderTests.java

@@ -6,6 +6,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.IOException;
 import java.util.concurrent.TimeUnit;
@@ -30,6 +31,7 @@ void testInitializationOptions() {
 
     assertEquals(LsStreamConnectionProvider.EDITOR_NAME, options.getEditorInfo().getName());
     assertEquals(LsStreamConnectionProvider.EDITOR_PLUGIN_NAME, options.getEditorPluginInfo().getName());
+    assertTrue(options.getCopilotCapabilities().isMcpSampling());
   }
 
   @Test

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/Constants.java

@@ -59,6 +59,10 @@ private Constants() {
   public static final String AUTO_APPROVE_UNMATCHED_FILE_OP = "autoApproveUnmatchedFileOp";
   public static final String AUTO_APPROVE_MCP_SERVERS = "autoApproveMcpServers";
   public static final String AUTO_APPROVE_MCP_TOOLS = "autoApproveMcpTools";
+  // Servers approved to skip the MCP sampling (inference) confirmation dialog. Kept separate from
+  // AUTO_APPROVE_MCP_SERVERS so that approving regular tool calls for a server never silently
+  // approves its (billable) sampling requests, and vice versa.
+  public static final String AUTO_APPROVE_MCP_SAMPLING_SERVERS = "autoApproveMcpSamplingServers";
   public static final String AUTO_APPROVE_TRUST_TOOL_ANNOTATIONS = "autoApproveTrustToolAnnotations";
   public static final String AUTO_APPROVE_YOLO_MODE = "autoApproveYoloMode";
 

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/chat/ChatEventsManager.java

@@ -4,13 +4,15 @@
 package com.microsoft.copilot.eclipse.core.chat;
 
 import java.util.LinkedHashSet;
+import java.util.List;
 import java.util.concurrent.CompletableFuture;
 
 import com.microsoft.copilot.eclipse.core.lsp.protocol.ChatProgressValue;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.InvokeClientToolConfirmationParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.InvokeClientToolParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.LanguageModelToolConfirmationResult;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.LanguageModelToolResult;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.McpSamplingConfig;
 
 /**
  * Provider for chat progress.
@@ -27,6 +29,11 @@ public class ChatEventsManager {
    */
   public ToolInvocationListener agentToolListener;
 
+  /**
+   * Provider of persisted MCP sampling approval preferences.
+   */
+  private McpSamplingConfigProvider mcpSamplingConfigProvider;
+
   /**
    * Creates a new chat progress provider.
    */
@@ -101,4 +108,38 @@ public CompletableFuture<LanguageModelToolResult[]> invokeAgentTool(InvokeClient
     }
     return this.agentToolListener.onToolInvocation(params);
   }
+
+  /**
+   * Registers the provider of persisted MCP sampling approval preferences.
+   *
+   * @param provider the provider to register
+   */
+  public void registerMcpSamplingConfigProvider(McpSamplingConfigProvider provider) {
+    this.mcpSamplingConfigProvider = provider;
+  }
+
+  /**
+   * Unregisters the MCP sampling config provider.
+   *
+   * @param provider the provider to unregister
+   */
+  public void unregisterMcpSamplingConfigProvider(McpSamplingConfigProvider provider) {
+    if (this.mcpSamplingConfigProvider == provider) {
+      this.mcpSamplingConfigProvider = null;
+    }
+  }
+
+  /**
+   * Reads the persisted sampling preferences for an MCP server. Returns a config with no
+   * auto-decision (requires confirmation, allows all models) when no provider is registered.
+   *
+   * @param serverName the MCP server name
+   * @return the sampling config for the server
+   */
+  public McpSamplingConfig getMcpSamplingConfig(String serverName) {
+    if (this.mcpSamplingConfigProvider == null) {
+      return new McpSamplingConfig(false, false, List.of());
+    }
+    return this.mcpSamplingConfigProvider.getMcpSamplingConfig(serverName);
+  }
 }

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/chat/ConfirmationAction.java

@@ -18,6 +18,12 @@ public class ConfirmationAction {
   /** Metadata key for the action type enum name. */
   public static final String META_ACTION = "action";
 
+  /** Metadata key for actions handled entirely by the confirmation UI. */
+  public static final String META_UI_ACTION = "uiAction";
+
+  /** UI action that reveals the prompt associated with a sampling request. */
+  public static final String UI_ACTION_REVIEW_PROMPT = "reviewPrompt";
+
   private final String label;
   private final boolean accept;
   private final ConfirmationActionScope scope;
@@ -74,6 +80,12 @@ public static ConfirmationAction skip(String label) {
     return new ConfirmationAction(label, false, null, null, false);
   }
 
+  /** Creates an action that reveals the sampling prompt without resolving the confirmation. */
+  public static ConfirmationAction reviewPrompt(String label) {
+    return new ConfirmationAction(label, false, null,
+        Map.of(META_UI_ACTION, UI_ACTION_REVIEW_PROMPT), false);
+  }
+
   @Override
   public int hashCode() {
     return Objects.hash(accept, label, metadata, primary, scope);

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/chat/McpSamplingConfigProvider.java

@@ -0,0 +1,22 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+package com.microsoft.copilot.eclipse.core.chat;
+
+import com.microsoft.copilot.eclipse.core.lsp.protocol.McpSamplingConfig;
+
+/**
+ * Provides the persisted MCP sampling (inference) approval preferences for a server, so that the
+ * {@code copilot/readMcpSamplingConfig} language server request reflects the user's actual
+ * previously-cached decisions instead of always requiring re-confirmation.
+ */
+public interface McpSamplingConfigProvider {
+
+  /**
+   * Reads the sampling preferences for the given MCP server.
+   *
+   * @param serverName the MCP server name, may be {@code null}
+   * @return the persisted sampling config for the server
+   */
+  McpSamplingConfig getMcpSamplingConfig(String serverName);
+}

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/lsp/CopilotLanguageClient.java

@@ -57,10 +57,12 @@
 import com.microsoft.copilot.eclipse.core.lsp.protocol.InvokeClientToolParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.LanguageModelToolResult;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.LanguageModelToolResult.ToolInvocationStatus;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.McpSamplingConfig;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.OnChangeMcpServerToolsParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.RateLimitWarningParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.ReadDirectoryResult;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.ReadFileResult;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.ReadMcpSamplingConfigParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.codingagent.CodingAgentMessageRequestParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.codingagent.CodingAgentMessageResult;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.policy.DidChangePolicyParams;
@@ -181,6 +183,16 @@ public CompletableFuture<Object[]> confirmClientTool(InvokeClientToolConfirmatio
     });
   }
 
+  /**
+   * Read the sampling preferences for an MCP server.
+   */
+  @JsonRequest("copilot/readMcpSamplingConfig")
+  public CompletableFuture<Object[]> readMcpSamplingConfig(ReadMcpSamplingConfigParams params) {
+    McpSamplingConfig config = CopilotCore.getPlugin().getChatEventsManager()
+        .getMcpSamplingConfig(params.serverName());
+    return CompletableFuture.completedFuture(new Object[] { config, null });
+  }
+
   @Override
   public CompletableFuture<List<Object>> configuration(ConfigurationParams params) {
     return CompletableFuture.supplyAsync(() -> {

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/lsp/protocol/CopilotCapabilities.java

@@ -32,6 +32,10 @@ public class CopilotCapabilities {
 
   private boolean manageTodoListTool;
 
+  // Always advertised as supported; Eclipse always implements the client side of MCP sampling
+  // (the confirmation dialog and readMcpSamplingConfig handler), so this is not user-configurable.
+  private final boolean mcpSampling = true;
+
   private List<String> contentProvider;
 
   /**
@@ -112,6 +116,10 @@ public void setManageTodoListTool(boolean manageTodoListTool) {
     this.manageTodoListTool = manageTodoListTool;
   }
 
+  public boolean isMcpSampling() {
+    return mcpSampling;
+  }
+
   @Override
   public String toString() {
     ToStringBuilder builder = new ToStringBuilder(this);
@@ -124,13 +132,14 @@ public String toString() {
     builder.append("contentProvider", contentProvider);
     builder.append("debuggerAgent", debuggerAgent);
     builder.append("manageTodoListTool", manageTodoListTool);
+    builder.append("mcpSampling", mcpSampling);
     return builder.toString();
   }
 
   @Override
   public int hashCode() {
     return Objects.hash(cveRemediatorAgent, debuggerAgent, didChangeFeatureFlags, fetch, manageTodoListTool,
-        stateDatabase, subAgent, watchedFiles, contentProvider);
+        mcpSampling, stateDatabase, subAgent, watchedFiles, contentProvider);
   }
 
   @Override
@@ -145,8 +154,8 @@ public boolean equals(Object obj) {
 
     return cveRemediatorAgent == other.cveRemediatorAgent && debuggerAgent == other.debuggerAgent
         && didChangeFeatureFlags == other.didChangeFeatureFlags && fetch == other.fetch
-        && manageTodoListTool == other.manageTodoListTool && stateDatabase == other.stateDatabase
-        && subAgent == other.subAgent && watchedFiles == other.watchedFiles
+        && manageTodoListTool == other.manageTodoListTool && mcpSampling == other.mcpSampling
+        && stateDatabase == other.stateDatabase && subAgent == other.subAgent && watchedFiles == other.watchedFiles
         && Objects.equals(contentProvider, other.contentProvider);
   }
 }

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/lsp/protocol/McpSamplingConfig.java

@@ -0,0 +1,12 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+package com.microsoft.copilot.eclipse.core.lsp.protocol;
+
+import java.util.List;
+
+/**
+ * User preferences for MCP sampling requests from a server.
+ */
+public record McpSamplingConfig(boolean alwaysAllow, boolean alwaysDeny, List<String> allowedModels) {
+}

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/lsp/protocol/ReadMcpSamplingConfigParams.java

@@ -0,0 +1,10 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+package com.microsoft.copilot.eclipse.core.lsp.protocol;
+
+/**
+ * Parameters for reading MCP sampling preferences.
+ */
+public record ReadMcpSamplingConfigParams(String serverName) {
+}