diff --git a/src/main/java/io/codef/api/EasyCodef.java b/src/main/java/io/codef/api/EasyCodef.java
index 53e1c05..9b9bdab 100644
--- a/src/main/java/io/codef/api/EasyCodef.java
+++ b/src/main/java/io/codef/api/EasyCodef.java
@@ -24,10 +24,13 @@
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.IntStream;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class EasyCodef {
 
     private static final long REQUEST_DELAY_MS = 700L;
+    private static final Logger log = LoggerFactory.getLogger(EasyCodef.class);
 
     private final SimpleAuthStorage simpleAuthStorage;
     private final MultipleRequestStorage multipleRequestStorage;
@@ -35,15 +38,30 @@ public class EasyCodef {
     private final CodefClientType clientType;
     private final EasyCodefToken easyCodefToken;
 
-    protected EasyCodef(
-        EasyCodefBuilder builder,
-        EasyCodefToken easyCodefToken
-    ) {
+    protected EasyCodef(EasyCodefBuilder builder) {
+
         this.publicKey = RsaUtil.generatePublicKey(builder.getPublicKey());
+        log.info("EasyCodef RSA public key successfully initialized.");
+
         this.clientType = builder.getClientType();
-        this.easyCodefToken = easyCodefToken;
+        log.info("Your Codef clientType {} is successfully initialized.", clientType);
+
+        this.easyCodefToken = new EasyCodefToken(builder);
         this.simpleAuthStorage = new SimpleAuthStorage();
         this.multipleRequestStorage = new MultipleRequestStorage();
+
+        log.info("==================================================");
+        log.info("Your EasyCodef Entity is successfully initialized!");
+        log.info("==================================================\n");
+    }
+
+    private List<EasyCodefResponse> returnFirstErrorResponse(
+        EasyCodefResponse firstResponse,
+        String transactionId
+    ) {
+        log.info("Result Status Code : {}", firstResponse.code());
+
+        return List.of(firstResponse);
     }
 
     /**
@@ -53,10 +71,10 @@ public EasyCodefResponse requestProduct(EasyCodefRequest request) throws CodefEx
         String requestUrl = buildRequestUrl(request);
         EasyCodefToken validToken = easyCodefToken.validateAndRefreshToken();
 
-        EasyCodefResponse response = EasyCodefConnector.requestProduct(request, validToken,
-            requestUrl);
-        simpleAuthStorage.storeIfRequired(request, response, requestUrl);
+        EasyCodefResponse response =
+            EasyCodefConnector.requestProduct(request, validToken, requestUrl);
 
+        simpleAuthStorage.storeIfRequired(request, response, requestUrl);
         return response;
     }
 
@@ -66,9 +84,11 @@ public EasyCodefResponse requestProduct(EasyCodefRequest request) throws CodefEx
     public EasyCodefResponse requestMultipleProduct(List<EasyCodefRequest> requests)
         throws CodefException {
         validateRequests(requests);
+        easyCodefToken.validateAndRefreshToken();
         assignSsoId(requests, UUID.randomUUID().toString());
 
         var executors = createExecutors();
+
         try {
             return processMultipleRequests(requests, executors);
         } finally {
@@ -82,6 +102,7 @@ public EasyCodefResponse requestMultipleProduct(List<EasyCodefRequest> requests)
     public EasyCodefResponse requestSimpleAuthCertification(String transactionId)
         throws CodefException {
         CodefSimpleAuth simpleAuth = simpleAuthStorage.get(transactionId);
+        easyCodefToken.validateAndRefreshToken();
 
         EasyCodefRequest enrichedRequest = enrichRequestWithTwoWayInfo(simpleAuth);
         EasyCodefResponse response = executeSimpleAuthRequest(enrichedRequest,
@@ -94,6 +115,8 @@ public EasyCodefResponse requestSimpleAuthCertification(String transactionId)
             transactionId
         );
 
+        log.info("Result Status Code : {}", response.code());
+
         return response;
     }
 
@@ -103,10 +126,11 @@ public EasyCodefResponse requestSimpleAuthCertification(String transactionId)
     public List<EasyCodefResponse> requestMultipleSimpleAuthCertification(String transactionId)
         throws CodefException {
         CodefSimpleAuth simpleAuth = simpleAuthStorage.get(transactionId);
+        easyCodefToken.validateAndRefreshToken();
 
         EasyCodefRequest enrichedRequest = enrichRequestWithTwoWayInfo(simpleAuth);
-        EasyCodefResponse firstResponse = executeSimpleAuthRequest(enrichedRequest,
-            simpleAuth.requestUrl());
+        EasyCodefResponse firstResponse =
+            executeSimpleAuthRequest(enrichedRequest, simpleAuth.requestUrl());
 
         simpleAuthStorage.updateIfRequired(
             simpleAuth.requestUrl(),
@@ -116,8 +140,8 @@ public List<EasyCodefResponse> requestMultipleSimpleAuthCertification(String tra
         );
 
         return isSuccessful(firstResponse)
-            ? combineWithRemainingResponses(firstResponse, transactionId)
-            : List.of(firstResponse);
+            ? combineWithRemainingResponses(firstResponse, transactionId) // Case CF-00000
+            : returnFirstErrorResponse(firstResponse, transactionId);
     }
 
     // Private helper methods
@@ -153,10 +177,20 @@ private List<EasyCodefResponse> combineWithRemainingResponses(
         EasyCodefResponse firstResponse,
         String transactionId
     ) throws CodefException {
-        List<EasyCodefResponse> remainingResponses = multipleRequestStorage.getRemainingResponses(
-            transactionId);
+
+        log.info("remainingResponses called By transactionId `{}`", transactionId);
+
+        List<EasyCodefResponse> remainingResponses =
+            multipleRequestStorage.getRemainingResponses(transactionId);
+
+        log.info("Await Response Count = {}", remainingResponses.size());
         List<EasyCodefResponse> allResponses = new ArrayList<>(remainingResponses);
         allResponses.add(firstResponse);
+
+        log.info("Total Response Count = {}", allResponses.size());
+        log.info("Result Status Codes : {}",
+            allResponses.stream().map(EasyCodefResponse::code).toList());
+
         return allResponses;
     }
 
@@ -180,12 +214,12 @@ private EasyCodefResponse processMultipleRequests(
         List<EasyCodefRequest> requests,
         CodefExecutors codefExecutors
     ) throws CodefException {
-        List<CompletableFuture<EasyCodefResponse>> futures = scheduleRequests(requests,
-            codefExecutors);
+        List<CompletableFuture<EasyCodefResponse>> futures =
+            scheduleRequests(requests, codefExecutors);
 
-        CompletableFuture<EasyCodefResponse> firstCompleted = CompletableFuture.anyOf(
-            futures.toArray(new CompletableFuture[0])
-        ).thenApply(result -> (EasyCodefResponse) result);
+        CompletableFuture<EasyCodefResponse> firstCompleted =
+            CompletableFuture.anyOf(futures.toArray(new CompletableFuture[0]))
+                .thenApply(result -> (EasyCodefResponse) result);
 
         EasyCodefResponse result = firstCompleted.join();
         multipleRequestStorage.store(result.transactionId(), futures);
diff --git a/src/main/java/io/codef/api/EasyCodefBuilder.java b/src/main/java/io/codef/api/EasyCodefBuilder.java
index 25f3307..f3e5226 100644
--- a/src/main/java/io/codef/api/EasyCodefBuilder.java
+++ b/src/main/java/io/codef/api/EasyCodefBuilder.java
@@ -39,9 +39,8 @@ public EasyCodefBuilder clientType(CodefClientType clientType) {
 
     public EasyCodef build() {
         validatePropertyArguments();
-        EasyCodefToken easyCodefToken = new EasyCodefToken(this);
 
-        return new EasyCodef(this, easyCodefToken);
+        return new EasyCodef(this);
     }
 
     private void validatePropertyArguments() {
diff --git a/src/main/java/io/codef/api/EasyCodefConnector.java b/src/main/java/io/codef/api/EasyCodefConnector.java
index 1f7f462..250a824 100644
--- a/src/main/java/io/codef/api/EasyCodefConnector.java
+++ b/src/main/java/io/codef/api/EasyCodefConnector.java
@@ -11,15 +11,19 @@
 import io.codef.api.dto.EasyCodefResponse;
 import io.codef.api.error.CodefError;
 import io.codef.api.error.CodefException;
+import io.codef.api.logger.JsonLogUtil;
 import io.codef.api.util.HttpClientUtil;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import org.apache.hc.client5.http.classic.methods.HttpPost;
 import org.apache.hc.core5.http.ClassicHttpResponse;
 import org.apache.hc.core5.http.io.entity.StringEntity;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class EasyCodefConnector {
 
+    private static final Logger log = LoggerFactory.getLogger(EasyCodefConnector.class);
     private static final ResponseHandler responseHandler = new ResponseHandler();
 
     private EasyCodefConnector() {
@@ -74,7 +78,19 @@ private static <T> T executeRequest(
         ResponseProcessor<T> processor
     ) {
         try (var httpClient = HttpClientUtil.createClient()) {
-            return httpClient.execute(request, processor::process);
+            log.info("[{}] Codef API Request", request.hashCode());
+            log.info("> Request Host : {}://{}", request.getScheme(),
+                request.getAuthority().toString());
+            log.info("> Requset Uri : {}\n", request.getRequestUri());
+
+            return httpClient.execute(request, response -> {
+                log.info("[{}] Codef API Response", request.hashCode());
+                log.info("> Response Status : {}", response.getCode());
+                T result = processor.process(response);
+                log.info("> Response →\n{}\n", JsonLogUtil.toPrettyJson(result));
+
+                return result;
+            });
         } catch (IOException exception) {
             throw CodefException.of(CodefError.IO_ERROR, exception);
         }
diff --git a/src/main/java/io/codef/api/EasyCodefToken.java b/src/main/java/io/codef/api/EasyCodefToken.java
index 0a304f0..6eeec8a 100644
--- a/src/main/java/io/codef/api/EasyCodefToken.java
+++ b/src/main/java/io/codef/api/EasyCodefToken.java
@@ -3,14 +3,19 @@
 import java.time.LocalDateTime;
 import java.util.Base64;
 import java.util.Optional;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class EasyCodefToken {
 
+    private static final Logger log = LoggerFactory.getLogger(EasyCodefToken.class);
+
     private final String oauthToken;
     private String accessToken;
     private LocalDateTime expiresAt;
 
     protected EasyCodefToken(EasyCodefBuilder builder) {
+
         final int VALIDITY_PERIOD_DAYS = 7;
         final String DELIMITER = ":";
 
@@ -18,13 +23,23 @@ protected EasyCodefToken(EasyCodefBuilder builder) {
             builder.getClientSecret().toString());
 
         this.oauthToken = Base64.getEncoder().encodeToString(combinedKey.getBytes());
+        log.info("Codef OAuth Token : {}", oauthToken);
+        log.info("Codef OAuth Token successfully initialized.\n");
+
         this.accessToken = EasyCodefConnector.requestToken(oauthToken);
+        log.info("Codef API AccessToken : {}", accessToken);
+
         this.expiresAt = LocalDateTime.now().plusDays(VALIDITY_PERIOD_DAYS);
+
+        log.info(
+            "Codef API AccessToken expiry at {} but, EasyCodef will handle automatic renewal",
+            expiresAt
+        );
+        log.info("Codef API AccessToken successfully initialized.\n");
     }
 
     public EasyCodefToken validateAndRefreshToken() {
-        Optional.of(expiresAt)
-            .filter(this::isTokenExpiringSoon)
+        Optional.of(expiresAt).filter(this::isTokenExpiringSoon)
             .ifPresent(expiry -> refreshToken());
 
         return this;
@@ -32,11 +47,23 @@ public EasyCodefToken validateAndRefreshToken() {
 
     private boolean isTokenExpiringSoon(LocalDateTime expiry) {
         return expiry.isBefore(LocalDateTime.now().plusHours(24));
+
     }
 
     private void refreshToken() {
+        log.info(
+            "Codef API AccessToken expiry at {} so EasyCodef refresh token",
+            expiresAt
+        );
         this.accessToken = EasyCodefConnector.requestToken(oauthToken);
+        log.info("Codef API AccessToken : {}", accessToken);
+
         this.expiresAt = LocalDateTime.now().plusDays(7);
+
+        log.info(
+            "AccessToken Refresh completed. Now, Codef accessToken expiry at {}.",
+            expiresAt
+        );
     }
 
     public String getAccessToken() {
diff --git a/src/main/java/io/codef/api/constants/CodefReferenceUrl.java b/src/main/java/io/codef/api/constants/CodefReferenceUrl.java
index 9648332..0c61ca5 100644
--- a/src/main/java/io/codef/api/constants/CodefReferenceUrl.java
+++ b/src/main/java/io/codef/api/constants/CodefReferenceUrl.java
@@ -25,4 +25,8 @@ public enum CodefReferenceUrl {
     public String getUrl() {
         return String.format(MESSAGE_FORMAT, url);
     }
+
+    public String getRawUrl() {
+        return url;
+    }
 }
diff --git a/src/main/java/io/codef/api/dto/EasyCodefRequestBuilder.java b/src/main/java/io/codef/api/dto/EasyCodefRequestBuilder.java
index 589f000..5d3a6aa 100644
--- a/src/main/java/io/codef/api/dto/EasyCodefRequestBuilder.java
+++ b/src/main/java/io/codef/api/dto/EasyCodefRequestBuilder.java
@@ -12,9 +12,13 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class EasyCodefRequestBuilder {
 
+    private static final Logger log = LoggerFactory.getLogger(EasyCodefRequestBuilder.class);
+
     private final HashMap<String, Object> generalRequestBody;
     private final HashMap<String, String> secureRequestBody;
     private String path;
@@ -80,7 +84,13 @@ public EasyCodefRequest build() {
         this.requestBody(EASY_CODEF_JAVA_FLAG, true);
         this.generalRequestBody.putAll(secureRequestBody);
 
-        return new EasyCodefRequest(path, generalRequestBody);
+        EasyCodefRequest easyCodefRequest = new EasyCodefRequest(path, generalRequestBody);
+
+//        log.info("[EasyCodef] request object has been successfully built [ {} ]");
+//        log.info(">> path = {}", path);
+//        log.info(">> requestBody = {}", generalRequestBody);
+
+        return easyCodefRequest;
     }
 
     private void encryptSecureRequestBody() {
diff --git a/src/main/java/io/codef/api/error/CodefError.java b/src/main/java/io/codef/api/error/CodefError.java
index 5d60de4..f5ffb95 100644
--- a/src/main/java/io/codef/api/error/CodefError.java
+++ b/src/main/java/io/codef/api/error/CodefError.java
@@ -116,4 +116,12 @@ public enum CodefError {
     public String getMessage() {
         return String.format(MESSAGE_FORMAT, message, referenceUrl.getUrl());
     }
+
+    public String getRawMessage() {
+        return message;
+    }
+
+    public CodefReferenceUrl getReferenceUrl() {
+        return referenceUrl;
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/io/codef/api/error/CodefException.java b/src/main/java/io/codef/api/error/CodefException.java
index 846d5a4..42c65f6 100644
--- a/src/main/java/io/codef/api/error/CodefException.java
+++ b/src/main/java/io/codef/api/error/CodefException.java
@@ -1,12 +1,15 @@
 package io.codef.api.error;
 
 import java.io.Serial;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class CodefException extends RuntimeException {
 
     @Serial
     private static final long serialVersionUID = 1L;
 
+    private static final Logger log = LoggerFactory.getLogger(CodefException.class);
     private static final String LOG_WITH_CAUSE_FORMAT = "%s\n→ %s\n\n";
 
     private final CodefError codefError;
@@ -21,6 +24,9 @@ private CodefException(CodefError codefError, Exception exception) {
             exception
         );
         this.codefError = codefError;
+
+        log.error(codefError.getMessage());
+        log.error(exception.getMessage());
     }
 
     private CodefException(
@@ -28,11 +34,17 @@ private CodefException(
         String extraMessage
     ) {
         super(codefError.getMessage() + '\n' + extraMessage);
+        log.error(codefError.getMessage());
+        log.error(extraMessage);
         this.codefError = codefError;
     }
 
     private CodefException(CodefError codefError) {
         super(codefError.getMessage() + '\n');
+
+        log.error("{}", codefError.getRawMessage());
+        log.error("{}", codefError.getReferenceUrl().getRawUrl());
+
         this.codefError = codefError;
     }
 
diff --git a/src/main/java/io/codef/api/logger/JsonLogUtil.java b/src/main/java/io/codef/api/logger/JsonLogUtil.java
new file mode 100644
index 0000000..08b36ff
--- /dev/null
+++ b/src/main/java/io/codef/api/logger/JsonLogUtil.java
@@ -0,0 +1,19 @@
+package io.codef.api.logger;
+
+import com.alibaba.fastjson2.JSON;
+import com.alibaba.fastjson2.JSONWriter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class JsonLogUtil {
+
+    private static final Logger log = LoggerFactory.getLogger(JsonLogUtil.class);
+
+    public static String toPrettyJson(Object obj) {
+        return JSON.toJSONString(obj,
+            JSONWriter.Feature.PrettyFormat,
+            JSONWriter.Feature.WriteMapNullValue,
+            JSONWriter.Feature.WriteNullListAsEmpty
+        );
+    }
+}
\ No newline at end of file