refactor: Migrate MCP Gateway to Spring AI MCP Server

axhub-gateway/build.gradle

@@ -8,6 +8,9 @@ dependencies {
     implementation 'org.springframework.boot:spring-boot-starter-web'
     implementation 'org.springframework.boot:spring-boot-starter-data-redis'
     
+    // Spring AI MCP Server
+    implementation 'org.springframework.ai:spring-ai-starter-mcp-server-webmvc'
+    
     // MyBatis & DB
     implementation 'org.springframework.boot:spring-boot-starter-jdbc'
     implementation 'org.mybatis.spring.boot:mybatis-spring-boot-starter:3.0.3'

axhub-gateway/src/main/java/io/shinhanlife/axhub/biz/mcp/gateway/presentation/McpRouterController.java

@@ -60,97 +60,7 @@ public class McpRouterController {
         this.restClient = RestClient.builder().requestFactory(factory).build();
     }
 
-    @Operation(summary = "MCP 파이프라인 호출", description = "MCP 표준 파이프라인(ExecuteService)을 통해 레거시 툴을 호출합니다.")
-    @PostMapping("/tools/call")
-    public ResponseEntity<Object> callTool(
-            @RequestHeader(value = "X-Trace-Id", required = false) String traceId,
-            @RequestHeader(value = "X-Agent-Id", required = false) String agentId,
-            @RequestHeader(value = "X-User-Prompt", required = false) String userPrompt,
-            @RequestBody Map<String, Object> payload, 
-            @RequestAttribute(value = "tenantId", required = false) String tenantId) {
-            
-        Map<String, Object> meta = new HashMap<>();
-        meta.put("traceId", traceId != null ? traceId : UUID.randomUUID().toString());
-        meta.put("agentId", agentId != null ? agentId : "UNKNOWN");
-        meta.put("userPrompt", userPrompt != null ? userPrompt : "");
-        payload.put("meta", meta);
-        
-        log.info("[MCP 표준] ExecuteService 파이프라인을 통한 툴 호출 시작 (Tenant: {}, Trace: {})", tenantId, meta.get("traceId"));
-        
-        try {
-            log.info("[AI -> MCP Gateway] 동적 툴 실행 요청 수신: {}", objectMapper.writeValueAsString(payload));
-        } catch (Exception ex) {
-            log.info("[AI -> MCP Gateway] 동적 툴 실행 요청 수신: {}", payload);
-        }
 
-        try {
-            Object result = executeService.execute(payload, tenantId);
-            
-            try {
-                log.info("[MCP Gateway -> AI] 동적 툴 실행 결과 반환: {}", objectMapper.writeValueAsString(result));
-            } catch (Exception ex) {
-                log.info("[MCP Gateway -> AI] 동적 툴 실행 결과 반환: {}", result);
-            }
-            
-            return ResponseEntity.ok(result);
-        } catch (SecurityException se) {
-            log.warn(" [보안 차단] 권한 오류: {}", se.getMessage());
-            return ResponseEntity.status(403).body(Map.of("error", se.getMessage()));
-        } catch (Exception e) {
-            log.error(" 파이프라인 실행 중 오류: {}", e.getMessage());
-            return ResponseEntity.internalServerError().body(Map.of("error", e.getMessage()));
-        }
-    }
-
-    @GetMapping("/tools/list")
-    public ResponseEntity<JsonRpcResponse> listTools(
-            @RequestParam(value = "categoryKey", required = false) String categoryKey) {
-        List<ToolMetadata> activeTools = redisRegistryService.getAllTools()
-                .stream()
-                .filter(ToolMetadata::getVisible)
-                .collect(Collectors.toList());
-                
-        Set<String> knownTools = activeTools.stream()
-                .map(ToolMetadata::getUid)
-                .collect(Collectors.toSet());
-
-        Set<String> fallbackUrls = new HashSet<>(gatewayFallbackProperties.getRoutes().values());
-        if (gatewayFallbackProperties.getDefaultUrl() != null) {
-            fallbackUrls.add(gatewayFallbackProperties.getDefaultUrl());
-        }
-
-        for (String url : fallbackUrls) {
-            try {
-                List<ToolMetadata> localTools = restClient.get()
-                        .uri(url + "/mcp/api/v1/tools/local")
-                        .retrieve()
-                        .body(new ParameterizedTypeReference<List<ToolMetadata>>() {});
-                        
-                if (localTools != null) {
-                    for (ToolMetadata t : localTools) {
-                        if (!Boolean.TRUE.equals(t.getIsRegistered()) && Boolean.TRUE.equals(t.getVisible()) && !knownTools.contains(t.getUid())) {
-                            activeTools.add(t);
-                            knownTools.add(t.getUid());
-                        }
-                    }
-                }
-            } catch (Exception e) {
-                log.warn("Failed to fetch local tools from fallback URL: {}", url);
-            }
-        }
-        
-        if (categoryKey != null && !categoryKey.trim().isEmpty()) {
-            activeTools = activeTools.stream()
-                    .filter(t -> categoryKey.equals(t.getCategoryKey()))
-                    .collect(Collectors.toList());
-        }
-
-        JsonRpcResponse response = new JsonRpcResponse();
-        response.setId(UUID.randomUUID().toString());
-        response.setResult(Map.of("tools", activeTools));
-        
-        return ResponseEntity.ok(response);
-    }
 
     @GetMapping(value = "/tools/docs/markdown", produces = "text/markdown;charset=UTF-8")
     public ResponseEntity<String> generateToolsMarkdown() {

axhub-gateway/src/main/java/io/shinhanlife/axhub/biz/mcp/gateway/sync/RegistryMcpToolSpecificationFactory.java

@@ -0,0 +1,124 @@
+package io.shinhanlife.axhub.biz.mcp.gateway.sync;
+
+import io.shinhanlife.axhub.biz.mcp.gateway.dto.ToolMetadata;
+import io.shinhanlife.axhub.biz.mcp.gateway.service.ExecuteService;
+import io.modelcontextprotocol.server.McpStatelessServerFeatures;
+import io.modelcontextprotocol.spec.McpSchema;
+import org.springframework.stereotype.Component;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * Registry에 등록된 실제 Tool 메타데이터를 MCP 표준 Tool specification으로 변환합니다.
+ */
+@Component
+public class RegistryMcpToolSpecificationFactory {
+    
+    private final ExecuteService executeService;
+    private final ObjectMapper objectMapper;
+
+    public RegistryMcpToolSpecificationFactory(ExecuteService executeService, ObjectMapper objectMapper) {
+        this.executeService = executeService;
+        this.objectMapper = objectMapper;
+    }
+
+    /**
+     * Registry Entry 하나를 MCP SDK의 stateless sync Tool specification으로 변환합니다.
+     */
+    public McpStatelessServerFeatures.SyncToolSpecification create(ToolMetadata entry) {
+        McpSchema.Tool tool = McpSchema.Tool.builder()
+                .name(entry.getName())
+                .description(description(entry))
+                .inputSchema(inputSchema(entry))
+                .build();
+
+        return McpStatelessServerFeatures.SyncToolSpecification.builder()
+                .tool(tool)
+                .callHandler((context, request) -> execute(entry.getName(), request))
+                .build();
+    }
+
+    private McpSchema.CallToolResult execute(String toolName, McpSchema.CallToolRequest request) {
+        try {
+            // Build legacy JSON-RPC payload format expected by ExecuteService
+            Map<String, Object> payload = new HashMap<>();
+            payload.put("jsonrpc", "2.0");
+            payload.put("method", "tools/call");
+            payload.put("id", UUID.randomUUID().toString());
+            
+            Map<String, Object> params = new HashMap<>();
+            params.put("name", toolName);
+            params.put("arguments", request.arguments());
+            payload.put("params", params);
+
+            // Execute through ExecuteService
+            Object rawResult = executeService.execute(payload, "system");
+            
+            // Convert JSON-RPC response back to McpSchema.CallToolResult
+            return toCallToolResult(rawResult);
+        } catch (Exception error) {
+            return McpSchema.CallToolResult.builder()
+                    .addTextContent("Tool 실행 중 내부 오류가 발생했습니다: " + error.getMessage())
+                    .isError(true)
+                    .build();
+        }
+    }
+
+    private McpSchema.CallToolResult toCallToolResult(Object rawResult) {
+        try {
+            Map<String, Object> resultMap = objectMapper.convertValue(rawResult, new TypeReference<Map<String, Object>>() {});
+            Object innerResult = resultMap.get("result");
+            
+            McpSchema.CallToolResult.Builder builder = McpSchema.CallToolResult.builder();
+            builder.isError(resultMap.containsKey("error"));
+            
+            if (innerResult instanceof Map) {
+                Map<String, Object> innerMap = (Map<String, Object>) innerResult;
+                // If it follows structured content
+                if (innerMap.containsKey("content")) {
+                    List<Map<String, Object>> contentList = (List<Map<String, Object>>) innerMap.get("content");
+                    for (Map<String, Object> item : contentList) {
+                        if ("text".equals(item.get("type"))) {
+                            builder.addTextContent((String) item.get("text"));
+                        }
+                    }
+                } else {
+                    // Fallback to text string representation
+                    builder.addTextContent(objectMapper.writeValueAsString(innerResult));
+                }
+            } else {
+                builder.addTextContent(String.valueOf(innerResult));
+            }
+            return builder.build();
+        } catch (Exception e) {
+            return McpSchema.CallToolResult.builder()
+                    .addTextContent(String.valueOf(rawResult))
+                    .build();
+        }
+    }
+
+    private Map<String, Object> inputSchema(ToolMetadata entry) {
+        if (entry.getParametersSchema() != null) {
+            return entry.getParametersSchema();
+        }
+        
+        Map<String, Object> schema = new LinkedHashMap<>();
+        schema.put("type", "object");
+        schema.put("properties", new HashMap<>());
+        schema.put("additionalProperties", false);
+        return schema;
+    }
+
+    private String description(ToolMetadata entry) {
+        return entry.getDescription() == null || entry.getDescription().isBlank()
+                ? entry.getName() + " Tool"
+                : entry.getDescription();
+    }
+}

axhub-gateway/src/main/java/io/shinhanlife/axhub/biz/mcp/gateway/sync/RegistryMcpToolSynchronizer.java

@@ -0,0 +1,87 @@
+package io.shinhanlife.axhub.biz.mcp.gateway.sync;
+
+import io.shinhanlife.axhub.biz.mcp.gateway.dto.ToolMetadata;
+import io.shinhanlife.axhub.biz.mcp.gateway.registry.RedisRegistryService;
+import io.modelcontextprotocol.server.McpStatelessSyncServer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.context.event.EventListener;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
+
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.stream.Collectors;
+
+/**
+ * MCP 서버의 tools/list 노출 목록을 Redis Registry의 ACTIVE Tool 목록과 동기화합니다.
+ */
+@Service
+public class RegistryMcpToolSynchronizer {
+    private static final Logger log = LoggerFactory.getLogger(RegistryMcpToolSynchronizer.class);
+
+    private final ObjectProvider<McpStatelessSyncServer> mcpServerProvider;
+    private final RedisRegistryService redisRegistryService;
+    private final RegistryMcpToolSpecificationFactory specificationFactory;
+    private final Set<String> managedToolNames = new LinkedHashSet<>();
+    private final ReentrantLock lock = new ReentrantLock();
+
+    public RegistryMcpToolSynchronizer(ObjectProvider<McpStatelessSyncServer> mcpServerProvider,
+                                       RedisRegistryService redisRegistryService,
+                                       RegistryMcpToolSpecificationFactory specificationFactory) {
+        this.mcpServerProvider = mcpServerProvider;
+        this.redisRegistryService = redisRegistryService;
+        this.specificationFactory = specificationFactory;
+    }
+
+    @EventListener(ApplicationReadyEvent.class)
+    public void synchronizeOnStartup() {
+        synchronize();
+    }
+
+    @Scheduled(fixedDelayString = "${mcp.tool-registry-sync-interval-millis:5000}")
+    public void synchronizeScheduled() {
+        synchronize();
+    }
+
+    public void synchronize() {
+        McpStatelessSyncServer server = mcpServerProvider.getIfAvailable();
+        if (server == null) {
+            return;
+        }
+
+        lock.lock();
+        try {
+            List<ToolMetadata> activeEntries = redisRegistryService.getAllTools()
+                    .stream().filter(ToolMetadata::getVisible).collect(Collectors.toList());
+                    
+            Set<String> activeNames = activeEntries.stream()
+                    .map(ToolMetadata::getName) // We use 'name' for MCP Tool Name
+                    .collect(Collectors.toCollection(LinkedHashSet::new));
+
+            Set<String> removedNames = new LinkedHashSet<>(managedToolNames);
+            removedNames.removeAll(activeNames);
+            for (String removedName : removedNames) {
+                server.removeTool(removedName);
+                managedToolNames.remove(removedName);
+                log.info("Removed MCP registry tool. tool={}", removedName);
+            }
+
+            for (ToolMetadata entry : activeEntries) {
+                if (managedToolNames.contains(entry.getName())) {
+                    server.removeTool(entry.getName());
+                }
+                server.addTool(specificationFactory.create(entry));
+                managedToolNames.add(entry.getName());
+            }
+        } catch (Exception error) {
+            log.warn("MCP registry tool synchronization failed. message={}", error.getMessage());
+        } finally {
+            lock.unlock();
+        }
+    }
+}

axhub-gateway/src/main/resources/application.properties

@@ -28,3 +28,15 @@ server.shutdown=graceful
 spring.lifecycle.timeout-per-shutdown-phase=20s
 # Suppress Kafka Connection Logs
 logging.level.org.apache.kafka=ERROR
+
+# Spring AI MCP Server Settings
+spring.ai.mcp.server.protocol=STATELESS
+mcp.agent-claims-required=false
+mcp.trusted-claims-required=false
+mcp.write-approval-required=false
+mcp.default-page-size=100
+mcp.max-page-size=500
+mcp.max-pages-per-call=3
+mcp.max-stream-bytes=1048576
+mcp.max-response-bytes-from-tool=5242880
+mcp.tool-registry-sync-interval-millis=5000