feat: use MCP SDK for tool pod calls

dap-gateway/src/main/java/io/shinhanlife/dap/mcg/service/ExecuteService.java

@@ -261,7 +261,6 @@ public class ExecuteService {
                     if (metadata.getPodUrl() != null && !metadata.getPodUrl().isEmpty()) {
                         targetUrl = metadata.getPodUrl();
                     }
-                    String executeApiUrl = targetUrl + "/mcp/" + metadata.getName();
                     
                     Map<String, String> headers = new java.util.HashMap<>();
                     headers.put("trace-id", context.requestId());
@@ -279,16 +278,16 @@ public class ExecuteService {
                         
                         JsonNode data = null;
                         try {
-                            data = toolInvoker.invoke(pagePayload, executeApiUrl, headers);
+                            data = toolInvoker.invoke(metadata.getName(), pagePayload, targetUrl, headers);
                         } catch (org.springframework.web.client.RestClientResponseException e) {
                             // HTTP 4xx, 5xx 에러는 연결 오류가 아니라 비즈니스 로직 오류이거나 검증 실패이므로 원본 에러를 그대로 반환
                             throw new ToolExecutionException(FailureType.SERVER_ERROR, "Tool Pod HTTP 에러 (" + e.getStatusCode() + "): " + e.getResponseBodyAsString());
                         } catch (Exception e) {
-                            if (executeApiUrl.contains("http://tool-")) {
-                                String fallbackUrl = executeApiUrl.replaceAll("http://tool-[a-zA-Z0-9-]+", "http://localhost");
+                            if (targetUrl.contains("http://tool-")) {
+                                String fallbackUrl = targetUrl.replaceAll("http://tool-[a-zA-Z0-9-]+", "http://localhost");
                                 log.warn(" [ExecuteService] 호스트를 찾을 수 없어 localhost로 재시도합니다: {}", fallbackUrl);
                                 try {
-                                    data = toolInvoker.invoke(pagePayload, fallbackUrl, headers);
+                                    data = toolInvoker.invoke(metadata.getName(), pagePayload, fallbackUrl, headers);
                                 } catch (Exception ex) {
                                     throw new ToolExecutionException(FailureType.SERVER_ERROR, "Tool Pod 호출 실패 (localhost 재시도 포함): " + ex.getMessage());
                                 }
@@ -385,4 +384,4 @@ public class ExecuteService {
     public void shutdown() {
         executor.shutdownNow();
     }
-}
+}

dap-gateway/src/main/java/io/shinhanlife/dap/mcg/transport/HttpToolInvoker.java

@@ -1,69 +1,81 @@
 package io.shinhanlife.dap.mcg.transport;
 
-
-/**
- * @package io.shinhanlife.dap.mcg.transport
- * @className HttpToolInvoker
- * @description AX HUB 시스템 처리 클래스
- * @author 0986406
- * @create 2026.09.01
- * <pre>
- * ---------- 개정이력 ----------
- * 수정일      수정자    수정내용
- * ---------- -------- ---------------------------
- * 2026.09.01  0986406    최초생성
- * 
- * </pre>
- */
-import io.shinhanlife.dap.mcg.resilience.FailureType;
-import io.shinhanlife.dap.mcg.resilience.ToolExecutionException;
-import org.springframework.http.MediaType;
-import org.springframework.stereotype.Component;
-import org.springframework.web.client.RestClient;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import lombok.extern.slf4j.Slf4j;
-
+import com.fasterxml.jackson.databind.node.TextNode;
+import io.modelcontextprotocol.client.McpClient;
+import io.modelcontextprotocol.client.McpSyncClient;
+import io.modelcontextprotocol.client.transport.HttpClientStreamableHttpTransport;
+import io.modelcontextprotocol.spec.McpSchema;
+import io.shinhanlife.dap.mcg.resilience.FailureType;
+import io.shinhanlife.dap.mcg.resilience.ToolExecutionException;
+import java.net.http.HttpRequest;
+import java.time.Duration;
 import java.util.Map;
-import java.util.UUID;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
 
+/** MCP SDK client used for Gateway-to-Tool-Pod calls over Streamable HTTP. */
 @Slf4j
 @Component
 public class HttpToolInvoker implements ToolInvoker {
 
-    private final RestClient restClient;
     private final ObjectMapper objectMapper;
 
     public HttpToolInvoker(ObjectMapper objectMapper) {
         this.objectMapper = objectMapper;
-        this.restClient = RestClient.create();
     }
 
     @Override
-    public JsonNode invoke(Map<String, Object> payload, String targetUrl, Map<String, String> headers) {
-        try {
-            RestClient.RequestBodySpec requestSpec = restClient.post()
-                    .uri(targetUrl)
-                    .contentType(MediaType.APPLICATION_JSON);
-                    
-            if (headers != null) {
-                headers.forEach(requestSpec::header);
+    public JsonNode invoke(String toolName, Map<String, Object> arguments, String podUrl, Map<String, String> headers) {
+        String endpoint = podUrl.replaceAll("/+$", "") + "/mcp";
+        HttpRequest.Builder requestBuilder = HttpRequest.newBuilder();
+        if (headers != null) {
+            headers.forEach(requestBuilder::header);
+        }
+
+        HttpClientStreamableHttpTransport transport = HttpClientStreamableHttpTransport.builder(endpoint)
+                .requestBuilder(requestBuilder)
+                .connectTimeout(Duration.ofSeconds(5))
+                .build();
+        try (McpSyncClient client = McpClient.sync(transport)
+                .clientInfo(new McpSchema.Implementation("dap-gateway", "1.0.0"))
+                .requestTimeout(Duration.ofSeconds(30))
+                .build()) {
+            client.initialize();
+            McpSchema.CallToolResult result = client.callTool(McpSchema.CallToolRequest.builder()
+                    .name(toolName)
+                    .arguments(arguments)
+                    .build());
+            if (Boolean.TRUE.equals(result.isError())) {
+                throw new ToolExecutionException(FailureType.BUSINESS_ERROR, "Tool Pod MCP error: " + textContent(result));
             }
-            
-            Object httpResult = requestSpec.body(payload)
-                    .retrieve()
-                    .body(Object.class);
-            
-            return extractData(objectMapper.valueToTree(httpResult));
-        } catch (Exception e) {
-            throw new ToolExecutionException(FailureType.SERVER_ERROR, "Tool Pod HTTP 호출 실패: " + e.getMessage(), e);
+            return result.structuredContent() != null
+                    ? objectMapper.valueToTree(result.structuredContent())
+                    : textContentAsJson(result);
+        } catch (ToolExecutionException error) {
+            throw error;
+        } catch (Exception error) {
+            throw new ToolExecutionException(FailureType.SERVER_ERROR,
+                    "Tool Pod MCP call failed: " + error.getMessage(), error);
         }
     }
 
-    private JsonNode extractData(JsonNode root) {
-        if (!root.path("success").asBoolean(true)) {
-            throw new ToolExecutionException(FailureType.BUSINESS_ERROR, "Tool 서버 업무 오류: " + root.path("error").asText());
+    private JsonNode textContentAsJson(McpSchema.CallToolResult result) {
+        String text = textContent(result);
+        try {
+            return objectMapper.readTree(text);
+        } catch (Exception ignored) {
+            return TextNode.valueOf(text);
         }
-        return root.has("data") ? root.get("data") : root;
+    }
+
+    private String textContent(McpSchema.CallToolResult result) {
+        return result.content().stream()
+                .filter(McpSchema.TextContent.class::isInstance)
+                .map(McpSchema.TextContent.class::cast)
+                .map(McpSchema.TextContent::text)
+                .findFirst()
+                .orElse("");
     }
 }

dap-gateway/src/main/java/io/shinhanlife/dap/mcg/transport/ToolInvoker.java

@@ -22,5 +22,5 @@ import java.util.Map;
  * Tool 서버 호출 transport의 최소 공통 인터페이스입니다.
  */
 public interface ToolInvoker {
-    JsonNode invoke(Map<String, Object> payload, String targetUrl, Map<String, String> headers);
+    JsonNode invoke(String toolName, Map<String, Object> arguments, String podUrl, Map<String, String> headers);
 }

dap-tool-core/build.gradle

@@ -4,6 +4,7 @@ plugins {
 
 dependencies {
     api 'org.springframework.boot:spring-boot-starter-web'
+    api 'org.springframework.ai:spring-ai-starter-mcp-server-webmvc'
     api 'org.springframework.boot:spring-boot-starter-validation'
     api 'org.springframework.boot:spring-boot-starter-data-redis'
     
@@ -24,7 +25,7 @@ dependencies {
     
     api 'com.fasterxml.jackson.dataformat:jackson-dataformat-xml:2.17.1'
     api 'com.fasterxml.jackson.core:jackson-databind:2.17.1'
-    api 'com.networknt:json-schema-validator:1.4.0'
+    api 'com.networknt:json-schema-validator:3.0.0'
     api 'org.springframework.kafka:spring-kafka:3.2.0'
     api 'org.springdoc:springdoc-openapi-starter-webmvc-ui:2.5.0'
 }

dap-tool-core/src/main/java/io/shinhanlife/dap/mcc/mcp/ToolMcpServerConfiguration.java

@@ -0,0 +1,26 @@
+package io.shinhanlife.dap.mcc.mcp;
+
+import io.modelcontextprotocol.server.transport.HttpServletStreamableServerTransportProvider;
+import org.springframework.boot.web.servlet.ServletRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
+
+/** Exposes every Tool Pod through the MCP Streamable HTTP transport. */
+@Configuration
+public class ToolMcpServerConfiguration {
+
+    @Bean
+    @Primary
+    public HttpServletStreamableServerTransportProvider toolMcpTransportProvider() {
+        return HttpServletStreamableServerTransportProvider.builder()
+                .mcpEndpoint("/mcp")
+                .build();
+    }
+
+    @Bean
+    public ServletRegistrationBean<HttpServletStreamableServerTransportProvider> toolMcpServlet(
+            HttpServletStreamableServerTransportProvider transportProvider) {
+        return new ServletRegistrationBean<>(transportProvider, "/mcp");
+    }
+}

dap-tool-core/src/main/java/io/shinhanlife/dap/mcc/mcp/ToolPodMcpToolSynchronizer.java

@@ -0,0 +1,74 @@
+package io.shinhanlife.dap.mcc.mcp;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.modelcontextprotocol.server.McpServerFeatures;
+import io.modelcontextprotocol.server.McpSyncServer;
+import io.modelcontextprotocol.spec.McpSchema;
+import io.shinhanlife.dap.mcc.dto.ToolMetadata;
+import io.shinhanlife.dap.mcc.presentation.BusinessToolController;
+import io.shinhanlife.dap.mcc.usecase.ToolRegistryHeartbeatSender;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.context.event.EventListener;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
+
+/** Registers the Tool Pod's existing annotated tools with its MCP SDK server. */
+@Component
+public class ToolPodMcpToolSynchronizer {
+    private final McpSyncServer mcpServer;
+    private final ToolRegistryHeartbeatSender heartbeatSender;
+    private final BusinessToolController businessToolController;
+    private final ObjectMapper objectMapper;
+
+    public ToolPodMcpToolSynchronizer(McpSyncServer mcpServer, ToolRegistryHeartbeatSender heartbeatSender,
+                                      BusinessToolController businessToolController, ObjectMapper objectMapper) {
+        this.mcpServer = mcpServer;
+        this.heartbeatSender = heartbeatSender;
+        this.businessToolController = businessToolController;
+        this.objectMapper = objectMapper;
+    }
+
+    @EventListener(ApplicationReadyEvent.class)
+    public void registerLocalTools() {
+        heartbeatSender.getAllScannedTools().stream()
+                .filter(tool -> Boolean.TRUE.equals(tool.getVisible()))
+                .forEach(tool -> mcpServer.addTool(specification(tool)));
+    }
+
+    private McpServerFeatures.SyncToolSpecification specification(ToolMetadata tool) {
+        McpSchema.Tool mcpTool = McpSchema.Tool.builder()
+                .name(tool.getName())
+                .description(tool.getDescription() == null || tool.getDescription().isBlank() ? tool.getName() + " Tool" : tool.getDescription())
+                .inputSchema(tool.getParametersSchema() == null ? emptySchema() : tool.getParametersSchema())
+                .annotations(McpSchema.ToolAnnotations.builder()
+                        .readOnlyHint(Boolean.TRUE.equals(tool.getReadOnlyHint()))
+                        .destructiveHint(Boolean.TRUE.equals(tool.getDestructiveHint()))
+                        .idempotentHint(Boolean.TRUE.equals(tool.getIdempotentHint()))
+                        .openWorldHint(Boolean.TRUE.equals(tool.getOpenWorldHint())).build())
+                .build();
+        return McpServerFeatures.SyncToolSpecification.builder().tool(mcpTool)
+                .callHandler((context, request) -> invoke(tool.getName(), request.arguments())).build();
+    }
+
+    private McpSchema.CallToolResult invoke(String toolName, Map<String, Object> arguments) {
+        ResponseEntity<?> response = businessToolController.executeDynamicTool(toolName, null, null, null, arguments);
+        boolean failed = !response.getStatusCode().is2xxSuccessful();
+        Object body = response.getBody();
+        try {
+            return McpSchema.CallToolResult.builder().addTextContent(objectMapper.writeValueAsString(body))
+                    .structuredContent(body).isError(failed).build();
+        } catch (Exception error) {
+            return McpSchema.CallToolResult.builder().addTextContent(String.valueOf(body)).isError(failed).build();
+        }
+    }
+
+    private Map<String, Object> emptySchema() {
+        Map<String, Object> schema = new LinkedHashMap<>();
+        schema.put("type", "object");
+        schema.put("properties", Map.of());
+        schema.put("additionalProperties", false);
+        return schema;
+    }
+}

dap-tool-core/src/main/java/io/shinhanlife/dap/mcc/presentation/BusinessToolController.java

@@ -16,10 +16,7 @@ package io.shinhanlife.dap.mcc.presentation;
  * </pre>
  */
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.networknt.schema.JsonSchema;
-import com.networknt.schema.JsonSchemaFactory;
-import com.networknt.schema.SpecVersion;
-import com.networknt.schema.ValidationMessage;
+import com.networknt.schema.Error;
 import io.shinhanlife.dap.lib.annotation.McpFunction;
 import io.shinhanlife.dap.lib.annotation.McpTool;
 import io.shinhanlife.dap.lib.config.McpProperties;
@@ -58,6 +55,7 @@ public class BusinessToolController {
     private final ObjectMapper objectMapper;
     private final McpProperties mcpProperties;
     private final ToolRegistryHeartbeatSender toolRegistryHeartbeatSender;
+    private final ToolArgumentSchemaValidator toolArgumentSchemaValidator;
 
     // 내부 조회용 로컬 Tool 목록 엔드포인트
     @GetMapping("/mcp/api/v1/tools/local")
@@ -149,17 +147,12 @@ public class BusinessToolController {
             if (!Map.class.isAssignableFrom(paramType)) {
                 try {
                     Map<String, Object> autoSchema = JsonSchemaGenerator.generateSchema(paramType);
-                    String fullSchemaJson = objectMapper.writeValueAsString(autoSchema);
-                    
-                    JsonSchemaFactory factory = JsonSchemaFactory.getInstance(SpecVersion.VersionFlag.V7);
-                    JsonSchema schema = factory.getSchema(fullSchemaJson);
-                    
-                    Set<ValidationMessage> errors = schema.validate(objectMapper.valueToTree(arguments));
+                    List<Error> errors = toolArgumentSchemaValidator.validate(autoSchema, arguments);
                     if (!errors.isEmpty()) {
                         log.error("[Tool] 파라미터 유효성 검증 실패: {}", errors);
                         List<String> errorMessages = new ArrayList<>();
-                        for (ValidationMessage vm : errors) {
-                            errorMessages.add(vm.getMessage());
+                        for (Error validationError : errors) {
+                            errorMessages.add(validationError.getMessage());
                         }
                         Map<String, Object> errorDetails = new HashMap<>();
                         errorDetails.put("status", "422");
@@ -229,4 +222,4 @@ public class BusinessToolController {
             return ResponseEntity.status(502).body(errorBody);
         }
     }
-}
+}

dap-tool-core/src/main/java/io/shinhanlife/dap/mcc/presentation/ToolArgumentSchemaValidator.java

@@ -0,0 +1,28 @@
+package io.shinhanlife.dap.mcc.presentation;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.networknt.schema.Error;
+import com.networknt.schema.InputFormat;
+import com.networknt.schema.Schema;
+import com.networknt.schema.SchemaRegistry;
+import com.networknt.schema.SpecificationVersion;
+import java.util.List;
+import java.util.Map;
+import org.springframework.stereotype.Component;
+
+/** Validates tool arguments with the NetworkNT version selected by the MCP SDK. */
+@Component
+public class ToolArgumentSchemaValidator {
+
+    private final ObjectMapper objectMapper;
+
+    public ToolArgumentSchemaValidator(ObjectMapper objectMapper) {
+        this.objectMapper = objectMapper;
+    }
+
+    public List<Error> validate(Map<String, Object> schemaDefinition, Map<String, Object> arguments) throws Exception {
+        SchemaRegistry schemaRegistry = SchemaRegistry.withDefaultDialect(SpecificationVersion.DRAFT_7);
+        Schema schema = schemaRegistry.getSchema(objectMapper.writeValueAsString(schemaDefinition));
+        return schema.validate(objectMapper.writeValueAsString(arguments), InputFormat.JSON);
+    }
+}

dap-tool-core/src/test/java/io/shinhanlife/dap/lib/util/JsonSchemaGeneratorTest.java

@@ -5,15 +5,15 @@ import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.networknt.schema.JsonSchema;
-import com.networknt.schema.JsonSchemaFactory;
-import com.networknt.schema.SpecVersion;
-import com.networknt.schema.ValidationMessage;
+import com.networknt.schema.Error;
+import com.networknt.schema.InputFormat;
+import com.networknt.schema.Schema;
+import com.networknt.schema.SchemaRegistry;
+import com.networknt.schema.SpecificationVersion;
 import io.shinhanlife.dap.lib.annotation.McpParameter;
 import io.shinhanlife.dap.lib.annotation.McpValidation;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import org.junit.jupiter.api.Test;
 
 /**
@@ -65,10 +65,10 @@ class JsonSchemaGeneratorTest {
     @Test
     void validatorRejectsInvalidNestedValue() throws Exception {
         ObjectMapper objectMapper = new ObjectMapper();
-        JsonSchema schema = JsonSchemaFactory.getInstance(SpecVersion.VersionFlag.V7)
+        Schema schema = SchemaRegistry.withDefaultDialect(SpecificationVersion.DRAFT_7)
                 .getSchema(objectMapper.writeValueAsString(JsonSchemaGenerator.generateSchema(NestedRequest.class)));
-        Set<ValidationMessage> errors = schema.validate(objectMapper.valueToTree(Map.of(
-                "child", Map.of("businessDate", "2026-07-28"))));
+        List<Error> errors = schema.validate(objectMapper.writeValueAsString(Map.of(
+                "child", Map.of("businessDate", "2026-07-28"))), InputFormat.JSON);
 
         assertFalse(errors.isEmpty());
     }

dap-tool-core/src/test/java/io/shinhanlife/dap/mcc/mcp/ToolMcpServerConfigurationTest.java

@@ -0,0 +1,22 @@
+package io.shinhanlife.dap.mcc.mcp;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+
+import io.modelcontextprotocol.server.transport.HttpServletStreamableServerTransportProvider;
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.web.servlet.ServletRegistrationBean;
+
+class ToolMcpServerConfigurationTest {
+
+    private final ToolMcpServerConfiguration configuration = new ToolMcpServerConfiguration();
+
+    @Test
+    void exposesOnlyExactMcpEndpointSoLegacyMcpApiPathsRemainAvailable() {
+        HttpServletStreamableServerTransportProvider transport = configuration.toolMcpTransportProvider();
+        ServletRegistrationBean<HttpServletStreamableServerTransportProvider> registration = configuration.toolMcpServlet(transport);
+
+        assertEquals("/mcp", registration.getUrlMappings().iterator().next());
+        assertFalse(registration.getUrlMappings().contains("/mcp/*"));
+    }
+}

dap-tool-core/src/test/java/io/shinhanlife/dap/mcc/presentation/ToolArgumentSchemaValidatorTest.java

@@ -0,0 +1,25 @@
+package io.shinhanlife.dap.mcc.presentation;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import java.util.List;
+import java.util.Map;
+import org.junit.jupiter.api.Test;
+
+class ToolArgumentSchemaValidatorTest {
+
+    private final ToolArgumentSchemaValidator validator = new ToolArgumentSchemaValidator(new ObjectMapper());
+
+    @Test
+    void validatesDraft7SchemaWithTheRuntimeNetworkntVersion() throws Exception {
+        Map<String, Object> schema = Map.of(
+                "type", "object",
+                "properties", Map.of("name", Map.of("type", "string")),
+                "required", List.of("name"));
+
+        assertTrue(validator.validate(schema, Map.of("name", "Hong")).isEmpty());
+        assertFalse(validator.validate(schema, Map.of()).isEmpty());
+    }
+}