diff --git a/boot/common-framework/src/main/java/com/klaro/acquirecore/framework/MessageCodec.java b/boot/common-framework/src/main/java/com/klaro/acquirecore/framework/MessageCodec.java
index f3b84de..e699fbe 100644
--- a/boot/common-framework/src/main/java/com/klaro/acquirecore/framework/MessageCodec.java
+++ b/boot/common-framework/src/main/java/com/klaro/acquirecore/framework/MessageCodec.java
@@ -1,24 +1,133 @@
 package com.klaro.acquirecore.framework;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
 import org.springframework.stereotype.Component;
 
-/**
- * 레거시 {@code msg_layout.h} 고정길이 전문(電文) 코덱의 Spring 빈 자리표시자.
- *
- * <p>실 전환에서는 고정길이(positional) 바이트 레이아웃 ↔ DTO 바인딩을 담당한다
- * (BeanIO 또는 커스텀 코덱). 지금은 스켈레톤이 빈으로 뜨는지만 증명한다.
- */
-@Component
-public class MessageCodec {
+import java.util.Map;
 
-    /** 고정길이 필드를 우측을 공백으로 채워 정규화한다 (자리표시자 구현). */
-    public String padRight(String value, int width) {
-        if (value == null) {
-            value = "";
+/**
+ * Message codec interface and JSON implementation.
+ * Provides encoding/decoding of TxRequest and TxResponse.
+ */
+public interface MessageCodec {
+
+    byte[] encodeRequest(TxRequest request);
+    TxRequest decodeRequest(byte[] data);
+    byte[] encodeResponse(TxResponse response);
+    TxResponse decodeResponse(byte[] data);
+    String getContentType();
+
+    @Component
+    class JsonMessageCodec implements MessageCodec {
+
+        private final ObjectMapper objectMapper;
+
+        public JsonMessageCodec() {
+            this.objectMapper = new ObjectMapper()
+                    .configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false)
+                    .configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
         }
-        if (value.length() >= width) {
-            return value.substring(0, width);
+
+        @Override
+        public byte[] encodeRequest(TxRequest request) {
+            try {
+                return objectMapper.writeValueAsBytes(new RequestDto(
+                        request.getServiceName(),
+                        request.getPayload(),
+                        request.getContext() != null ? request.getContext().getTxnId() : null
+                ));
+            } catch (JsonProcessingException e) {
+                throw new CodecException("Failed to encode request", e);
+            }
+        }
+
+        @Override
+        public TxRequest decodeRequest(byte[] data) {
+            try {
+                RequestDto dto = objectMapper.readValue(data, RequestDto.class);
+                return new TxRequest(dto.serviceName, dto.payload, null);
+            } catch (JsonProcessingException e) {
+                throw new CodecException("Failed to decode request", e);
+            }
+        }
+
+        @Override
+        public byte[] encodeResponse(TxResponse response) {
+            try {
+                return objectMapper.writeValueAsBytes(new ResponseDto(
+                        response.getResult().name(),
+                        response.getResult().getCode(),
+                        response.getData(),
+                        response.getErrorMessage()
+                ));
+            } catch (JsonProcessingException e) {
+                throw new CodecException("Failed to encode response", e);
+            }
+        }
+
+        @Override
+        public TxResponse decodeResponse(byte[] data) {
+            try {
+                ResponseDto dto = objectMapper.readValue(data, ResponseDto.class);
+                return new TxResponse(
+                        TxCore.TxResult.fromCode(dto.resultCode),
+                        dto.data,
+                        dto.errorMessage
+                );
+            } catch (JsonProcessingException e) {
+                throw new CodecException("Failed to decode response", e);
+            }
+        }
+
+        @Override
+        public String getContentType() {
+            return "application/json";
+        }
+
+        public <T> T decode(byte[] data, Class<T> type) {
+            try {
+                return objectMapper.readValue(data, type);
+            } catch (JsonProcessingException e) {
+                throw new CodecException("Failed to decode data", e);
+            }
+        }
+
+        private static class RequestDto {
+            public String serviceName;
+            public Map<String, Object> payload;
+            public Long txnId;
+
+            public RequestDto() {}
+
+            public RequestDto(String serviceName, Map<String, Object> payload, Long txnId) {
+                this.serviceName = serviceName;
+                this.payload = payload;
+                this.txnId = txnId;
+            }
+        }
+
+        private static class ResponseDto {
+            public String result;
+            public int resultCode;
+            public Map<String, Object> data;
+            public String errorMessage;
+
+            public ResponseDto() {}
+
+            public ResponseDto(String result, int resultCode, Map<String, Object> data, String errorMessage) {
+                this.result = result;
+                this.resultCode = resultCode;
+                this.data = data;
+                this.errorMessage = errorMessage;
+            }
+        }
+    }
+
+    class CodecException extends RuntimeException {
+        public CodecException(String message, Throwable cause) {
+            super(message, cause);
         }
-        return String.format("%-" + width + "s", value);
     }
 }