diff --git a/.cocoindex_code/cocoindex.db/mdb/data.mdb b/.cocoindex_code/cocoindex.db/mdb/data.mdb
index fe49e35..d984184 100644
Binary files a/.cocoindex_code/cocoindex.db/mdb/data.mdb and b/.cocoindex_code/cocoindex.db/mdb/data.mdb differ
diff --git a/.cocoindex_code/target_sqlite.db b/.cocoindex_code/target_sqlite.db
index 88fa5f4..55fe3ef 100644
Binary files a/.cocoindex_code/target_sqlite.db and b/.cocoindex_code/target_sqlite.db differ
diff --git a/app/Database/Migrations/2026-03-25-000050_CreateAuditLogs.php b/app/Database/Migrations/2026-03-25-000050_CreateAuditLogs.php
new file mode 100644
index 0000000..6a3ea60
--- /dev/null
+++ b/app/Database/Migrations/2026-03-25-000050_CreateAuditLogs.php
@@ -0,0 +1,137 @@
+<?php
+
+namespace App\Database\Migrations;
+
+use CodeIgniter\Database\Migration;
+
+class CreateAuditLogs extends Migration
+{
+    private array $logTables = [
+        'logpatient' => 'LogPatientID',
+        'logorder'   => 'LogOrderID',
+        'logmaster'  => 'LogMasterID',
+        'logsystem'  => 'LogSystemID',
+    ];
+
+    public function up(): void
+    {
+        foreach ($this->logTables as $table => $pk) {
+            $this->createLogTable($table, $pk);
+        }
+    }
+
+    public function down(): void
+    {
+        foreach (array_reverse($this->logTables) as $table => $pk) {
+            $this->forge->dropTable($table, true);
+        }
+    }
+
+    private function createLogTable(string $table, string $primaryKey): void
+    {
+        $fields = [
+            $primaryKey => [
+                'type'           => 'BIGINT',
+                'constraint'     => 20,
+                'unsigned'       => true,
+                'auto_increment' => true,
+            ],
+            'TblName' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 64,
+            ],
+            'RecID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 64,
+            ],
+            'FldName' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 128,
+                'null'       => true,
+            ],
+            'FldValuePrev' => [
+                'type' => 'TEXT',
+                'null' => true,
+            ],
+            'FldValueNew' => [
+                'type' => 'TEXT',
+                'null' => true,
+            ],
+            'UserID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 64,
+            ],
+            'SiteID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 32,
+            ],
+            'DIDType' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 32,
+                'null'       => true,
+            ],
+            'DID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 128,
+                'null'       => true,
+            ],
+            'MachineID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 128,
+                'null'       => true,
+            ],
+            'SessionID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 128,
+            ],
+            'AppID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 64,
+            ],
+            'ProcessID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 128,
+                'null'       => true,
+            ],
+            'WebPageID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 128,
+                'null'       => true,
+            ],
+            'EventID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 80,
+            ],
+            'ActivityID' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 24,
+            ],
+            'Reason' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 512,
+                'null'       => true,
+            ],
+            'LogDate' => [
+                'type'       => 'DATETIME',
+                'constraint' => 3,
+            ],
+            'Context' => [
+                'type' => 'JSON',
+            ],
+            'IpAddress' => [
+                'type'       => 'VARCHAR',
+                'constraint' => 45,
+                'null'       => true,
+            ],
+        ];
+
+        $this->forge->addField($fields);
+        $this->forge->addKey($primaryKey, true);
+        $this->forge->addKey(['LogDate'], false, false, "idx_{$table}_logdate");
+        $this->forge->addKey(['RecID', 'LogDate'], false, false, "idx_{$table}_recid_logdate");
+        $this->forge->addKey(['UserID', 'LogDate'], false, false, "idx_{$table}_userid_logdate");
+        $this->forge->addKey(['EventID', 'LogDate'], false, false, "idx_{$table}_eventid_logdate");
+        $this->forge->addKey(['SiteID', 'LogDate'], false, false, "idx_{$table}_site_logdate");
+        $this->forge->createTable($table, true);
+    }
+}
diff --git a/app/Libraries/Data/_meta.json b/app/Libraries/Data/_meta.json
index 94d432c..3ebdb22 100644
--- a/app/Libraries/Data/_meta.json
+++ b/app/Libraries/Data/_meta.json
@@ -9,7 +9,8 @@
     {"file": "marital_status.json","VSName": "Marital Status"},
     {"file": "death_indicator.json","VSName": "Death Indicator"},
     {"file": "identifier_type.json","VSName": "Identifier Type"},
-    {"file": "operation.json","VSName": "Operation (CRUD)"},
+    {"file": "operation.json","VSName": "Operation (CRUD)"},
+    {"file": "event_id.json","VSName": "Audit Event ID"},
     {"file": "did_type.json","VSName": "DID Type"},
     {"file": "requested_entity.json","VSName": "Requested Entity"},
     {"file": "order_priority.json","VSName": "Order Priority"},
diff --git a/app/Libraries/Data/event_id.json b/app/Libraries/Data/event_id.json
new file mode 100644
index 0000000..a6b7f10
--- /dev/null
+++ b/app/Libraries/Data/event_id.json
@@ -0,0 +1,79 @@
+{
+  "name": "event_id",
+  "VSName": "Audit Event ID",
+  "VCategory": "System",
+  "values": [
+    {"key": "PATIENT_REGISTERED", "value": "Patient registered"},
+    {"key": "PATIENT_DEMOGRAPHICS_UPDATED", "value": "Patient demographics updated"},
+    {"key": "PATIENT_MERGED", "value": "Patient merged"},
+    {"key": "PATIENT_UNMERGED", "value": "Patient unmerged"},
+    {"key": "PATIENT_IDENTIFIER_UPDATED", "value": "Patient identifier updated"},
+    {"key": "PATIENT_CONSENT_UPDATED", "value": "Patient consent updated"},
+    {"key": "PATIENT_INSURANCE_UPDATED", "value": "Patient insurance updated"},
+    {"key": "PATIENT_DELETED", "value": "Patient deleted"},
+    {"key": "VISIT_ADMITTED", "value": "Visit admitted"},
+    {"key": "VISIT_TRANSFERRED", "value": "Visit transferred"},
+    {"key": "VISIT_DISCHARGED", "value": "Visit discharged"},
+    {"key": "VISIT_STATUS_UPDATED", "value": "Visit status updated"},
+    {"key": "ORDER_CREATED", "value": "Order created"},
+    {"key": "ORDER_CANCELLED", "value": "Order cancelled"},
+    {"key": "ORDER_REOPENED", "value": "Order reopened"},
+    {"key": "ORDER_TEST_ADDED", "value": "Order test added"},
+    {"key": "ORDER_TEST_REMOVED", "value": "Order test removed"},
+    {"key": "SPECIMEN_COLLECTED", "value": "Specimen collected"},
+    {"key": "SPECIMEN_RECEIVED", "value": "Specimen received"},
+    {"key": "SPECIMEN_REJECTED", "value": "Specimen rejected"},
+    {"key": "SPECIMEN_ALIQUOTED", "value": "Specimen aliquoted"},
+    {"key": "SPECIMEN_DISPOSED", "value": "Specimen disposed"},
+    {"key": "RESULT_ENTERED", "value": "Result entered"},
+    {"key": "RESULT_UPDATED", "value": "Result updated"},
+    {"key": "RESULT_VERIFIED", "value": "Result verified"},
+    {"key": "RESULT_AMENDED", "value": "Result amended"},
+    {"key": "RESULT_RELEASED", "value": "Result released"},
+    {"key": "RESULT_RETRACTED", "value": "Result retracted"},
+    {"key": "RESULT_CORRECTED", "value": "Result corrected"},
+    {"key": "QC_RECORDED", "value": "QC recorded"},
+    {"key": "QC_FAILED", "value": "QC failed"},
+    {"key": "QC_OVERRIDE_APPLIED", "value": "QC override applied"},
+    {"key": "VALUESET_ITEM_CREATED", "value": "Value set item created"},
+    {"key": "VALUESET_ITEM_UPDATED", "value": "Value set item updated"},
+    {"key": "VALUESET_ITEM_RETIRED", "value": "Value set item retired"},
+    {"key": "TEST_DEFINITION_UPDATED", "value": "Test definition updated"},
+    {"key": "REFERENCE_RANGE_UPDATED", "value": "Reference range updated"},
+    {"key": "TEST_PANEL_MEMBERSHIP_UPDATED", "value": "Test panel membership updated"},
+    {"key": "ANALYZER_CONFIG_UPDATED", "value": "Analyzer config updated"},
+    {"key": "INTEGRATION_CONFIG_UPDATED", "value": "Integration config updated"},
+    {"key": "CODING_SYSTEM_UPDATED", "value": "Coding system updated"},
+    {"key": "USER_CREATED", "value": "User created"},
+    {"key": "USER_DISABLED", "value": "User disabled"},
+    {"key": "USER_PASSWORD_RESET", "value": "User password reset"},
+    {"key": "USER_ROLE_CHANGED", "value": "User role changed"},
+    {"key": "USER_PERMISSION_CHANGED", "value": "User permission changed"},
+    {"key": "SITE_CREATED", "value": "Site created"},
+    {"key": "SITE_UPDATED", "value": "Site updated"},
+    {"key": "WORKSTATION_UPDATED", "value": "Workstation updated"},
+    {"key": "AUTH_LOGIN_SUCCESS", "value": "Auth login success"},
+    {"key": "AUTH_LOGOUT_SUCCESS", "value": "Auth logout success"},
+    {"key": "AUTH_LOGIN_FAILED", "value": "Auth login failed"},
+    {"key": "AUTH_LOCKOUT_TRIGGERED", "value": "Auth lockout triggered"},
+    {"key": "TOKEN_ISSUED", "value": "Token issued"},
+    {"key": "TOKEN_REFRESHED", "value": "Token refreshed"},
+    {"key": "TOKEN_REVOKED", "value": "Token revoked"},
+    {"key": "AUTHORIZATION_FAILED", "value": "Authorization failed"},
+    {"key": "IMPORT_JOB_STARTED", "value": "Import job started"},
+    {"key": "IMPORT_JOB_FINISHED", "value": "Import job finished"},
+    {"key": "EXPORT_JOB_STARTED", "value": "Export job started"},
+    {"key": "EXPORT_JOB_FINISHED", "value": "Export job finished"},
+    {"key": "JOB_STARTED", "value": "Job started"},
+    {"key": "JOB_FINISHED", "value": "Job finished"},
+    {"key": "INTEGRATION_SYNC_STARTED", "value": "Integration sync started"},
+    {"key": "INTEGRATION_SYNC_FINISHED", "value": "Integration sync finished"},
+    {"key": "AUDIT_WRITE_FAILED", "value": "Audit write failed"},
+    {"key": "AUDIT_ARCHIVE_EXECUTED", "value": "Audit archive executed"},
+    {"key": "AUDIT_PURGE_EXECUTED", "value": "Audit purge executed"},
+    {"key": "AUDIT_CHECKSUM_CREATED", "value": "Audit checksum created"},
+    {"key": "AUDIT_CHECKSUM_FAILED", "value": "Audit checksum failed"},
+    {"key": "LEGAL_HOLD_APPLIED", "value": "Legal hold applied"},
+    {"key": "LEGAL_HOLD_RELEASED", "value": "Legal hold released"}
+  ]
+}
diff --git a/app/Models/Patient/PatientModel.php b/app/Models/Patient/PatientModel.php
index 3753b9e..3f267ac 100644
--- a/app/Models/Patient/PatientModel.php
+++ b/app/Models/Patient/PatientModel.php
@@ -152,17 +152,24 @@ class PatientModel extends BaseModel {
       $newInternalPID = $this->getInsertID();
       $this->checkDbError($db, 'Insert patient');
       
-      AuditService::logData(
-        'CREATE',
-        'patient',
-        (string) $newInternalPID,
-        'patient',
-        null,
-        $previousData,
-        $input,
-        'Patient registration',
-        ['PatientID' => $input['PatientID'] ?? null]
-      );
+      $auditDiff = $this->buildAuditDiff([], $input);
+      AuditService::logData(
+        'PATIENT_REGISTERED',
+        'CREATE',
+        'patient',
+        (string) $newInternalPID,
+        'patient',
+        null,
+        null,
+        null,
+        'Patient registration',
+        [
+          'diff' => $auditDiff,
+          'patient_id' => $input['PatientID'] ?? null,
+          'validation_profile' => 'patient.create',
+        ],
+        ['entity_version' => 1]
+      );
 
       if (!empty($patIdt)) {
         $modelPatIdt->createPatIdt($patIdt, $newInternalPID);
@@ -219,16 +226,23 @@ class PatientModel extends BaseModel {
       $this->checkDbError($db, 'Update patient');
       
       $changedFields = array_keys(array_diff_assoc((array) $previousData, (array) $input));
+      $auditDiff = $this->buildAuditDiff((array) $previousData, $input);
       AuditService::logData(
+        'PATIENT_DEMOGRAPHICS_UPDATED',
         'UPDATE',
         'patient',
         (string) $InternalPID,
         'patient',
         null,
-        (array) $previousData,
-        $input,
+        null,
+        null,
         'Patient data updated',
-        ['changed_fields' => $changedFields]
+        [
+          'diff' => $auditDiff,
+          'changed_fields' => $changedFields,
+          'validation_profile' => 'patient.update',
+        ],
+        ['entity_version' => 1]
       );
 
       if (!empty($input['PatIdt'])) {
@@ -335,25 +349,43 @@ class PatientModel extends BaseModel {
     }
   }
 
-  private function formatedDateForDisplay($dateString) {    
-    $date = \DateTime::createFromFormat('Y-m-d H:i', $dateString);
-
-    if (!$date) {
-      $timestamp = strtotime($dateString);
-      if ($timestamp) {
-        return date('j M Y', $timestamp);
-      }
-      return null;
-    }
-
-    return $date->format('j M Y');
-  }
-
-  private function checkDbError($db, string $context) {
-      $error = $db->error();
-      if (!empty($error['code'])) {
-          throw new \Exception(
-              "{$context} failed: {$error['code']} - {$error['message']}"
+  private function formatedDateForDisplay($dateString) {    
+    $date = \DateTime::createFromFormat('Y-m-d H:i', $dateString);
+
+    if (!$date) {
+      $timestamp = strtotime($dateString);
+      if ($timestamp) {
+        return date('j M Y', $timestamp);
+      }
+      return null;
+    }
+
+    return $date->format('j M Y');
+  }
+
+  private function buildAuditDiff(array $before, array $after): array {
+      $diff = [];
+      $fields = array_unique(array_merge(array_keys($before), array_keys($after)));
+      foreach ($fields as $field) {
+          $prev = $before[$field] ?? null;
+          $next = $after[$field] ?? null;
+          if ($prev === $next) {
+              continue;
+          }
+          $diff[] = [
+              'field' => $field,
+              'previous' => $prev,
+              'new' => $next,
+          ];
+      }
+      return $diff;
+  }
+
+  private function checkDbError($db, string $context) {
+      $error = $db->error();
+      if (!empty($error['code'])) {
+          throw new \Exception(
+              "{$context} failed: {$error['code']} - {$error['message']}"
           );
       }
   }
@@ -371,17 +403,23 @@ class PatientModel extends BaseModel {
       $this->delete($InternalPID);
       $this->checkDbError($db, 'Delete patient');
       
-      AuditService::logData(
-        'DELETE',
-        'patient',
-        (string) $InternalPID,
-        'patient',
-        null,
-        $previousData,
-        [],
-        'Patient deleted',
-        ['PatientID' => $previousData['PatientID'] ?? null]
-      );
+      $auditDiff = $this->buildAuditDiff((array) $previousData, []);
+      AuditService::logData(
+        'PATIENT_DELETED',
+        'DELETE',
+        'patient',
+        (string) $InternalPID,
+        'patient',
+        null,
+        $previousData,
+        null,
+        'Patient deleted',
+        [
+          'diff' => $auditDiff,
+          'patient_id' => $previousData['PatientID'] ?? null,
+        ],
+        ['entity_version' => 1]
+      );
       
       $db->transCommit();
       return $InternalPID;
diff --git a/app/Services/AuditService.php b/app/Services/AuditService.php
index 334b715..cab8c3c 100644
--- a/app/Services/AuditService.php
+++ b/app/Services/AuditService.php
@@ -1,209 +1,346 @@
-<?php
-
-namespace App\Services;
-
-use CodeIgniter\Database\BaseConnection;
-
-class AuditService {
-  protected BaseConnection $db;
-
-  public function __construct() {
-    $this->db = \Config\Database::connect();
-  }
-
+<?php
+
+namespace App\Services;
+
+use App\Libraries\ValueSet;
+use CodeIgniter\Database\BaseConnection;
+use CodeIgniter\HTTP\IncomingRequest;
+use Config\Services;
+use DateTime;
+use DateTimeZone;
+
+class AuditService
+{
+    private const TABLE_MAP = [
+        'logpatient' => 'logpatient',
+        'patient'    => 'logpatient',
+        'visit'      => 'logpatient',
+        'logorder'   => 'logorder',
+        'order'      => 'logorder',
+        'specimen'   => 'logorder',
+        'result'     => 'logorder',
+        'logmaster'  => 'logmaster',
+        'master'     => 'logmaster',
+        'config'     => 'logmaster',
+        'valueset'   => 'logmaster',
+        'logsystem'  => 'logsystem',
+        'system'     => 'logsystem',
+        'auth'       => 'logsystem',
+        'job'        => 'logsystem',
+    ];
+
+    private const DEFAULT_APP_ID = 'clqms-api';
+    private const ENTITY_VERSION_DEFAULT = 1;
+
+    private static ?BaseConnection $db = null;
+    private static $session = null;
+    private static ?IncomingRequest $request = null;
+    private static ?array $eventIdCache = null;
+    private static ?string $cachedRequestId = null;
+
     public static function logData(
-    string $operation,
-    string $entityType,
-    string $entityId,
-    ?string $tableName = null,
-    ?string $fieldName = null,
-    ?array $previousValue = null,
-    ?array $newValue = null,
-    ?string $reason = null,
-    ?array $context = null
-  ): void {
-    self::log('data_audit_log', [
-      'operation' => $operation,
-      'entity_type' => $entityType,
-      'entity_id' => $entityId,
-      'table_name' => $tableName,
-      'field_name' => $fieldName,
-      'previous_value' => self::normalizeAuditValue($previousValue),
-      'new_value' => self::normalizeAuditValue($newValue),
-      'mechanism' => 'MANUAL',
-      'application_id' => 'CLQMS-WEB',
-      'web_page' => self::getUri(),
-      'session_id' => self::getSessionId(),
-      'event_type' => strtoupper($entityType) . '_' . strtoupper($operation),
-      'site_id' => self::getSiteId(),
-      'workstation_id' => self::getWorkstationId(),
-      'pc_name' => self::getPcName(),
-      'ip_address' => self::getIpAddress(),
-      'user_id' => self::getUserId(),
-      'reason' => $reason,
-      'context' => self::normalizeAuditValue($context),
-      'created_at' => date('Y-m-d H:i:s')
-    ]);
-  }
-
-  public static function logService(
-    string $operation,
-    string $entityType,
-    string $entityId,
-    string $serviceClass,
-    ?string $resourceType = null,
-    ?array $resourceDetails = null,
-    ?array $previousValue = null,
-    ?array $newValue = null,
-    ?string $serviceName = null,
-    ?array $context = null
-  ): void {
-    self::log('service_audit_log', [
-      'operation' => $operation,
-      'entity_type' => $entityType,
-      'entity_id' => $entityId,
-      'service_class' => $serviceClass,
-      'resource_type' => $resourceType,
-      'resource_details' => self::normalizeAuditValue($resourceDetails),
-      'previous_value' => self::normalizeAuditValue($previousValue),
-      'new_value' => self::normalizeAuditValue($newValue),
-      'mechanism' => 'AUTOMATIC',
-      'application_id' => $serviceName ?? 'SYSTEM-SERVICE',
-      'service_name' => $serviceName,
-      'session_id' => self::getSessionId() ?: 'service_session',
-      'event_type' => strtoupper($serviceClass) . '_' . strtoupper($operation),
-      'site_id' => self::getSiteId(),
-      'workstation_id' => self::getWorkstationId(),
-      'pc_name' => self::getPcName(),
-      'ip_address' => self::getIpAddress(),
-      'port' => $resourceDetails['port'] ?? null,
-      'user_id' => 'SYSTEM',
-      'reason' => null,
-      'context' => self::normalizeAuditValue($context),
-      'created_at' => date('Y-m-d H:i:s')
-    ]);
-  }
-
-  public static function logSecurity(
-    string $operation,
-    string $entityType,
-    string $entityId,
-    string $securityClass,
-    ?string $eventType = 'SUCCESS',
-    ?string $resourcePath = null,
-    ?array $previousValue = null,
-    ?array $newValue = null,
-    ?string $reason = null,
-    ?array $context = null
-  ): void {
-    self::log('security_audit_log', [
-      'operation' => $operation,
-      'entity_type' => $entityType,
-      'entity_id' => $entityId,
-      'security_class' => $securityClass,
-      'resource_path' => $resourcePath,
-      'previous_value' => self::normalizeAuditValue($previousValue),
-      'new_value' => self::normalizeAuditValue($newValue),
-      'mechanism' => 'MANUAL',
-      'application_id' => 'CLQMS-WEB',
-      'web_page' => self::getUri(),
-      'session_id' => self::getSessionId(),
-      'event_type' => $eventType,
-      'site_id' => self::getSiteId(),
-      'workstation_id' => self::getWorkstationId(),
-      'pc_name' => self::getPcName(),
-      'ip_address' => self::getIpAddress(),
-      'user_id' => self::getUserId() ?? 'UNKNOWN',
-      'reason' => $reason,
-      'context' => self::normalizeAuditValue($context),
-      'created_at' => date('Y-m-d H:i:s')
-    ]);
-  }
-
-  public static function logError(
-    string $entityType,
-    string $entityId,
-    string $errorCode,
-    string $errorMessage,
-    string $eventType,
-    ?array $errorDetails = null,
-    ?array $previousValue = null,
-    ?array $newValue = null,
-    ?string $reason = null,
-    ?array $context = null
-  ): void {
-    self::log('error_audit_log', [
-      'operation' => 'ERROR',
-      'entity_type' => $entityType,
-      'entity_id' => $entityId,
-      'error_code' => $errorCode,
-      'error_message' => $errorMessage,
-      'error_details' => self::normalizeAuditValue($errorDetails),
-      'previous_value' => self::normalizeAuditValue($previousValue),
-      'new_value' => self::normalizeAuditValue($newValue),
-      'mechanism' => 'AUTOMATIC',
-      'application_id' => 'CLQMS-WEB',
-      'web_page' => self::getUri(),
-      'session_id' => self::getSessionId() ?: 'system',
-      'event_type' => $eventType,
-      'site_id' => self::getSiteId(),
-      'workstation_id' => self::getWorkstationId(),
-      'pc_name' => self::getPcName(),
-      'ip_address' => self::getIpAddress(),
-      'user_id' => self::getUserId() ?? 'SYSTEM',
-      'reason' => $reason,
-      'context' => self::normalizeAuditValue($context),
-      'created_at' => date('Y-m-d H:i:s')
-    ]);
-  }
-
-  private static function log(string $table, array $data): void {
-    $db = \Config\Database::connect();
-    if (!$db->tableExists($table)) {
-        return;
+        string $eventId,
+        string $activityId,
+        string $entityType,
+        string $entityId,
+        string $tableName,
+        ?string $fldName = null,
+        $previousValue = null,
+        $newValue = null,
+        ?string $reason = null,
+        ?array $context = null,
+        array $options = []
+    ): void {
+        $sourceTable = $tableName ?: $entityType;
+        $logTable = self::resolveLogTable($sourceTable);
+        if ($logTable === null) {
+            log_message('warning', "AuditService cannot resolve log table for {$sourceTable}");
+            return;
+        }
+
+        $record = self::buildRecord(
+            $logTable,
+            self::normalizeEventId($eventId),
+            strtoupper($activityId),
+            $entityType,
+            $entityId,
+            $sourceTable,
+            $fldName,
+            $previousValue,
+            $newValue,
+            $reason,
+            $context,
+            $options
+        );
+
+        if ($record === null) {
+            return;
+        }
+
+        try {
+            self::getDb()->table($logTable)->insert($record);
+        } catch (\Throwable $e) {
+            log_message('error', "AuditService failed to insert into {$logTable}: {$e->getMessage()}");
+        }
     }
-    $db->table($table)->insert($data);
-  }
 
-  private static function normalizeAuditValue($value)
-  {
-      if ($value === null || is_scalar($value)) {
-          return $value;
-      }
+    private static function buildRecord(
+        string $logTable,
+        string $eventId,
+        string $activityId,
+        string $entityType,
+        string $entityId,
+        string $tblName,
+        ?string $fldName,
+        $previousValue,
+        $newValue,
+        ?string $reason,
+        ?array $context,
+        array $options
+    ): ?array {
+        $contextJson = self::buildContext($context, $options, $entityType);
+        if ($contextJson === null) {
+            return null;
+        }
 
-      $json = json_encode($value, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
-      return $json !== false ? $json : null;
-  }
-
-  private static function getUri(): ?string {
-    return $_SERVER['REQUEST_URI'] ?? null;
-  }
-
-  private static function getSessionId(): ?string {
-    $session = session();
-    return $session->get('session_id');
-  }
-
-  private static function getSiteId(): ?string {
-    $session = session();
-    return $session->get('site_id');
-  }
-
-  private static function getWorkstationId(): ?string {
-    $session = session();
-    return $session->get('workstation_id');
-  }
-
-  private static function getPcName(): ?string {
-    return gethostname();
-  }
-
-  private static function getIpAddress(): ?string {
-    return $_SERVER['REMOTE_ADDR'] ?? null;
-  }
-
-  private static function getUserId(): ?string {
-    $session = session();
-    return $session->get('user_id');
-  }
-}
+        return [
+            'TblName' => $tblName,
+            'RecID' => (string) $entityId,
+            'FldName' => $fldName,
+            'FldValuePrev' => self::serializeValue($previousValue),
+            'FldValueNew' => self::serializeValue($newValue),
+            'UserID' => self::resolveUserId($options),
+            'SiteID' => self::resolveSiteId($options),
+            'DIDType' => $options['did_type'] ?? null,
+            'DID' => $options['did'] ?? null,
+            'MachineID' => $options['machine_id'] ?? gethostname(),
+            'SessionID' => self::resolveSessionId($options),
+            'AppID' => $options['app_id'] ?? self::DEFAULT_APP_ID,
+            'ProcessID' => $options['process_id'] ?? null,
+            'WebPageID' => $options['web_page_id'] ?? self::resolveRoute($options),
+            'EventID' => $eventId,
+            'ActivityID' => $activityId,
+            'Reason' => $reason,
+            'LogDate' => self::nowWithMillis(),
+            'Context' => $contextJson,
+            'IpAddress' => self::resolveIpAddress(),
+        ];
+    }
+
+    private static function serializeValue($value): ?string
+    {
+        if ($value === null) {
+            return null;
+        }
+
+        if (is_scalar($value)) {
+            return (string) $value;
+        }
+
+        $json = json_encode($value, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
+        return $json !== false ? $json : null;
+    }
+
+    private static function buildContext(?array $context, array $options, string $entityType): ?string
+    {
+        $route = $options['route'] ?? self::resolveRoute($options);
+        $payload = array_merge(
+            [
+                'request_id' => $options['request_id'] ?? self::resolveRequestId(),
+                'route' => $route,
+                'timestamp_utc' => $options['timestamp_utc'] ?? self::timestampUtc(),
+                'entity_type' => $options['entity_type'] ?? $entityType,
+                'entity_version' => $options['entity_version'] ?? self::ENTITY_VERSION_DEFAULT,
+            ],
+            $context ?? []
+        );
+
+        $json = json_encode($payload, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
+        return $json !== false ? $json : null;
+    }
+
+    private static function resolveLogTable(?string $source): ?string
+    {
+        if ($source === null) {
+            return null;
+        }
+
+        $key = strtolower(trim($source));
+        return self::TABLE_MAP[$key] ?? null;
+    }
+
+    private static function resolveUserId(array $options): string
+    {
+        return $options['user_id'] ?? self::getSessionValue('user_id') ?? 'SYSTEM';
+    }
+
+    private static function resolveSiteId(array $options): string
+    {
+        return $options['site_id'] ?? self::getSessionValue('site_id') ?? 'GLOBAL';
+    }
+
+    private static function resolveSessionId(array $options): string
+    {
+        if (!empty($options['session_id'])) {
+            return $options['session_id'];
+        }
+
+        $session = self::getSession();
+        if ($session !== null && method_exists($session, 'getId')) {
+            $id = $session->getId();
+            if (!empty($id)) {
+                return $id;
+            }
+        }
+
+        if (session_status() === PHP_SESSION_ACTIVE) {
+            $id = session_id();
+            if (!empty($id)) {
+                return $id;
+            }
+        }
+
+        return self::generateUniqueId('sess');
+    }
+
+    private static function resolveRoute(array $options): string
+    {
+        if (!empty($options['route'])) {
+            return $options['route'];
+        }
+
+        $request = self::getRequest();
+        if ($request !== null) {
+            return trim(sprintf('%s %s', $request->getMethod(), $request->getUri()->getPath()));
+        }
+
+        return 'cli';
+    }
+
+    private static function resolveIpAddress(): ?string
+    {
+        $request = self::getRequest();
+        if ($request !== null) {
+            return $request->getIPAddress();
+        }
+
+        return $_SERVER['REMOTE_ADDR'] ?? null;
+    }
+
+    private static function normalizeEventId(string $eventId): string
+    {
+        $normalized = strtoupper(trim($eventId));
+        if (empty($normalized)) {
+            log_message('warning', 'AuditService received empty EventID');
+            return $eventId;
+        }
+
+        if (!self::isKnownEvent($normalized)) {
+            log_message('warning', "AuditService unknown EventID: {$normalized}");
+        }
+
+        return $normalized;
+    }
+
+    private static function isKnownEvent(string $eventId): bool
+    {
+        if (self::$eventIdCache === null) {
+            $raw = ValueSet::getRaw('event_id') ?? [];
+            self::$eventIdCache = array_filter(array_map(fn ($item) => $item['key'] ?? null, $raw));
+        }
+
+        return in_array($eventId, self::$eventIdCache, true);
+    }
+
+    private static function resolveRequestId(): string
+    {
+        if (self::$cachedRequestId !== null) {
+            return self::$cachedRequestId;
+        }
+
+        $request = self::getRequest();
+        if ($request !== null) {
+            $value = $request->getHeaderLine('X-Request-ID');
+            if (!empty($value)) {
+                self::$cachedRequestId = $value;
+                return $value;
+            }
+        }
+
+        foreach (['HTTP_X_REQUEST_ID', 'REQUEST_ID'] as $header) {
+            if (!empty($_SERVER[$header])) {
+                self::$cachedRequestId = $_SERVER[$header];
+                return self::$cachedRequestId;
+            }
+        }
+
+        return self::$cachedRequestId = self::generateUniqueId('req');
+    }
+
+    private static function nowWithMillis(): string
+    {
+        $dt = new DateTime('now', new DateTimeZone('UTC'));
+        return $dt->format('Y-m-d H:i:s.v');
+    }
+
+    private static function timestampUtc(): string
+    {
+        $dt = new DateTime('now', new DateTimeZone('UTC'));
+        return $dt->format('Y-m-d\TH:i:s.v\Z');
+    }
+
+    private static function getSessionValue(string $key): ?string
+    {
+        $session = self::getSession();
+        if ($session === null) {
+            return null;
+        }
+
+        if (!method_exists($session, 'get')) {
+            return null;
+        }
+
+        $value = $session->get($key);
+        return $value !== null ? (string) $value : null;
+    }
+
+    private static function getSession(): ?object
+    {
+        if (self::$session !== null) {
+            return self::$session;
+        }
+
+        try {
+            return self::$session = Services::session();
+        } catch (\Throwable $e) {
+            return self::$session = null;
+        }
+    }
+
+    private static function getRequest(): ?IncomingRequest
+    {
+        if (self::$request !== null) {
+            return self::$request;
+        }
+
+        try {
+            return self::$request = Services::request();
+        } catch (\Throwable $e) {
+            return self::$request = null;
+        }
+    }
+
+    private static function getDb(): BaseConnection
+    {
+        return self::$db ??= \Config\Database::connect();
+    }
+
+    private static function generateUniqueId(string $prefix): string
+    {
+        try {
+            return $prefix . '_' . bin2hex(random_bytes(8));
+        } catch (\Throwable $e) {
+            return uniqid("{$prefix}_", true);
+        }
+    }
+}
diff --git a/docs/audit-logging.md b/docs/audit-logging.md
index 26cfdf8..162de27 100644
--- a/docs/audit-logging.md
+++ b/docs/audit-logging.md
@@ -1,194 +1,352 @@
-# Audit Logging Strategy
+# Audit Logging Strategy (Implementation Ready)
 
-## Overview
+## 1) Purpose, Scope, and Non-Goals
 
-This document defines how CLQMS should capture audit and operational logs across four tables:
+This document defines the production audit logging contract for CLQMS.
 
-- `logpatient` — patient, visit, and ADT activity
-- `logorder` — orders, tests, specimens, results, and QC
-- `logmaster` — master data and configuration changes
-- `logsystem` — sessions, security, import/export, and system operations
+### Purpose
 
-The intent is to audit all domains, including master data changes, and to standardize event capture so reporting and compliance are consistent.
+- Provide a single, normalized audit model for compliance, investigations, and operations.
+- Ensure every protected workflow writes consistent, queryable audit records.
+- Make behavior deterministic across API controllers, services, jobs, and integrations.
 
-## Table Ownership
+### Scope
 
-| Event | Table |
-| --- | --- |
-| Patient registered/updated/merged | `logpatient` |
-| Insurance/consent changed | `logpatient` |
-| Patient visit (admit/transfer/discharge) | `logpatient` |
-| Order created/cancelled | `logorder` |
-| Sample received/rejected | `logorder` |
-| Result entered/verified/amended | `logorder` |
-| Result released/retracted/corrected | `logorder` |
-| QC result recorded | `logorder` |
-| Test panel added/removed | `logmaster` |
-| Reference range changed | `logmaster` |
-| Analyzer config updated | `logmaster` |
-| User role changed | `logmaster` |
-| User login/logout | `logsystem` |
-| Import/export job start/end | `logsystem` |
+This applies to four log tables:
 
-## Standard Log Schema (Shared Columns)
+- `logpatient` - patient identity, demographics, consent, insurance, and visit/ADT events.
+- `logorder` - orders, specimen lifecycle, results lifecycle, and QC.
+- `logmaster` - test/master configuration, value sets, role/permission updates, infrastructure configuration.
+- `logsystem` - authentication, authorization, import/export, jobs, and system integrity operations.
 
-Use a shared schema for all four tables to keep instrumentation and reporting consistent. The legacy names below match existing patterns and can be reused.
+### Non-goals
 
-| Column | Description |
-| --- | --- |
-| `LogID` (PK) | Auto increment primary key per table (e.g., `LogPatientID`) |
-| `TblName` | Source table name |
-| `RecID` | Record ID of the entity |
-| `FldName` | Field name that changed (nullable for bulk events) |
-| `FldValuePrev` | Previous value (string or JSON) |
-| `FldValueNew` | New value (string or JSON) |
-| `UserID` | Acting user ID (nullable for system actions) |
-| `SiteID` | Site context |
-| `DIDType` | Device identifier type |
-| `DID` | Device identifier |
-| `MachineID` | Workstation or host identifier |
-| `SessionID` | Session identifier |
-| `AppID` | Client application ID |
-| `ProcessID` | Process/workflow identifier |
-| `WebPageID` | UI page/context (nullable) |
-| `EventID` | Event code (see catalog) |
-| `ActivityID` | Action code (create/update/delete/read/etc.) |
-| `Reason` | User/system reason |
-| `LogDate` | Timestamp of event |
-| `Context` | JSON metadata (optional but recommended) |
-| `IpAddress` | Remote IP (optional but recommended) |
+- This is not a replacement for metrics/tracing systems (Prometheus, APM, etc.).
+- This is not a full immutable ledger; tamper evidence is implemented with controls described below.
 
-Recommended: keep a JSON string in `Context` for extra details (e.g., route, request id, batch id, error message). Use size limits to avoid oversized rows.
+## 2) Table Ownership
 
-## Event Catalog
+Use this mapping to choose the target table and minimum event shape.
 
-### logpatient
+| Event family | Table | Minimum keys in `Context` | Example `EventID` |
+| --- | --- | --- | --- |
+| Patient create/update/merge | `logpatient` | `route`, `request_id`, `entity_version` | `PATIENT_REGISTERED` |
+| Consent/insurance changes | `logpatient` | `consent_type` or `payer_id` | `PATIENT_CONSENT_UPDATED` |
+| Visit ADT transitions | `logpatient` | `visit_id`, `from_status`, `to_status` | `VISIT_TRANSFERRED` |
+| Order create/cancel/reopen | `logorder` | `order_id`, `priority`, `source` | `ORDER_CREATED` |
+| Specimen lifecycle | `logorder` | `specimen_id`, `specimen_status` | `SPECIMEN_RECEIVED` |
+| Result lifecycle | `logorder` | `result_id`, `verification_state` | `RESULT_AMENDED` |
+| QC lifecycle | `logorder` | `qc_run_id`, `instrument_id` | `QC_RECORDED` |
+| Value sets/test definitions | `logmaster` | `config_group`, `change_ticket` | `VALUESET_ITEM_RETIRED` |
+| Roles/permissions/users | `logmaster` | `target_user_id`, `target_role` | `USER_ROLE_CHANGED` |
+| Login/logout/token/auth failures | `logsystem` | `auth_flow`, `failure_reason` (on failure) | `AUTH_LOGIN_FAILED` |
+| Import/export/jobs/integration | `logsystem` | `batch_id`, `record_count`, `job_name` | `IMPORT_JOB_FINISHED` |
+| Purge/archive/legal hold | `logsystem` | `archive_id`, `policy_name`, `approved_by` | `AUDIT_PURGE_EXECUTED` |
 
-**Patient core**
+## 3) Canonical Schema (All Four Tables)
 
-- Register patient
-- Update demographics
-- Merge/unmerge/split
-- Identity changes (MRN, external identifiers)
-- Consent grant/revoke/update
-- Insurance add/update/remove
-- Patient record view (if required by compliance)
+All four tables MUST implement the same logical columns. Physical PK name may vary (`LogPatientID`, `LogOrderID`, etc.).
 
-**Visit/ADT**
+### 3.1 Column contract
 
-- Admit, transfer, discharge
-- Bed/ward/unit changes
-- Visit status updates
+| Column | Type | Required | Max length | Description | Example |
+| --- | --- | --- | --- | --- | --- |
+| `LogID` (or table-specific PK) | `BIGINT UNSIGNED AUTO_INCREMENT` | Yes | N/A | Surrogate key per table | `987654` |
+| `TblName` | `VARCHAR(64)` | Yes | 64 | Source business table | `patient` |
+| `RecID` | `VARCHAR(64)` | Yes | 64 | Primary identifier of affected entity | `PAT000123` |
+| `FldName` | `VARCHAR(128)` | Conditional | 128 | Changed field name, null for multi-field/bulk | `NameLast` |
+| `FldValuePrev` | `TEXT` | Conditional | 65535 | Previous value (string or JSON) | `{"status":"PENDING"}` |
+| `FldValueNew` | `TEXT` | Conditional | 65535 | New value (string or JSON) | `{"status":"VERIFIED"}` |
+| `UserID` | `VARCHAR(64)` | Yes | 64 | Actor user id, or `SYSTEM` for non-user actions | `USR001` |
+| `SiteID` | `VARCHAR(32)` | Yes | 32 | Facility/site context | `SITE01` |
+| `DIDType` | `VARCHAR(32)` | No | 32 | Device identifier type | `UUID` |
+| `DID` | `VARCHAR(128)` | No | 128 | Device identifier value | `6b8f...` |
+| `MachineID` | `VARCHAR(128)` | No | 128 | Host/workstation identifier | `WS-LAB-07` |
+| `SessionID` | `VARCHAR(128)` | Yes | 128 | Auth or workflow session identifier | `sess_abc123` |
+| `AppID` | `VARCHAR(64)` | Yes | 64 | Calling client/application id | `clqms-api` |
+| `ProcessID` | `VARCHAR(128)` | No | 128 | Process/workflow/job id | `job_20260325_01` |
+| `WebPageID` | `VARCHAR(128)` | No | 128 | UI route/page id if user-driven | `patient-detail` |
+| `EventID` | `VARCHAR(80)` | Yes | 80 | Canonical event code | `RESULT_RELEASED` |
+| `ActivityID` | `VARCHAR(24)` | Yes | 24 | Canonical action enum | `UPDATE` |
+| `Reason` | `VARCHAR(512)` | No | 512 | User/system reason or ticket reference | `Critical value corrected` |
+| `LogDate` | `DATETIME(3)` | Yes | N/A | Event time in UTC | `2026-03-25 04:45:12.551` |
+| `Context` | `JSON` (preferred) or `LONGTEXT` | Yes | N/A | Structured metadata payload | See section 5 |
+| `IpAddress` | `VARCHAR(45)` | No | 45 | IPv4/IPv6 remote address | `10.10.2.44` |
 
-**Other**
+### 3.2 Required/conditional rules
 
-- Patient notes/attachments added/removed
-- Patient alerts/flags changes
+- `FldName`, `FldValuePrev`, and `FldValueNew` are required for single-field changes.
+- For multi-field changes, set `FldName = NULL` and store a compact JSON diff under `Context.diff`.
+- For non-mutating events (`READ`, `LOGIN`, `EXPORT`, `IMPORT`), `FldValuePrev` and `FldValueNew` may be null.
+- `Context` is required for all rows. At minimum include `request_id` and `route` (or `job_name` for non-HTTP jobs).
 
-### logorder
+## 4) DDL Template and Indexing
 
-**Orders/tests**
+Use this template when creating a log table. Replace `${TABLE}` and `${PK}`.
 
-- Create/cancel/reopen order
-- Add/remove tests
-- Priority changes
-- Order comments added/removed
+```sql
+CREATE TABLE `${TABLE}` (
+  `${PK}` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
+  `TblName` VARCHAR(64) NOT NULL,
+  `RecID` VARCHAR(64) NOT NULL,
+  `FldName` VARCHAR(128) NULL,
+  `FldValuePrev` TEXT NULL,
+  `FldValueNew` TEXT NULL,
+  `UserID` VARCHAR(64) NOT NULL,
+  `SiteID` VARCHAR(32) NOT NULL,
+  `DIDType` VARCHAR(32) NULL,
+  `DID` VARCHAR(128) NULL,
+  `MachineID` VARCHAR(128) NULL,
+  `SessionID` VARCHAR(128) NOT NULL,
+  `AppID` VARCHAR(64) NOT NULL,
+  `ProcessID` VARCHAR(128) NULL,
+  `WebPageID` VARCHAR(128) NULL,
+  `EventID` VARCHAR(80) NOT NULL,
+  `ActivityID` VARCHAR(24) NOT NULL,
+  `Reason` VARCHAR(512) NULL,
+  `LogDate` DATETIME(3) NOT NULL,
+  `Context` JSON NOT NULL,
+  `IpAddress` VARCHAR(45) NULL,
+  PRIMARY KEY (`${PK}`),
+  INDEX `idx_${TABLE}_logdate` (`LogDate`),
+  INDEX `idx_${TABLE}_recid_logdate` (`RecID`, `LogDate`),
+  INDEX `idx_${TABLE}_userid_logdate` (`UserID`, `LogDate`),
+  INDEX `idx_${TABLE}_eventid_logdate` (`EventID`, `LogDate`),
+  INDEX `idx_${TABLE}_site_logdate` (`SiteID`, `LogDate`)
+);
+```
 
-**Specimen lifecycle**
+Optional JSON path index (DB engine specific):
 
-- Collected, labeled, received, rejected
-- Centrifuged, aliquoted, stored
-- Disposed/expired
+- `Context.request_id`
+- `Context.batch_id`
+- `Context.job_name`
 
-**Results**
+## 5) Context JSON Contract
 
-- Result entered/updated
-- Verified/amended
-- Released/retracted/corrected
-- Result comments/interpretation changes
-- Auto-verification override
+`Context` MUST be valid JSON. Keep payload compact and predictable.
 
-**QC**
+### 5.1 Required keys for all events
 
-- QC result recorded
-- QC failure/override
+```json
+{
+  "request_id": "a4f5b6c7",
+  "route": "PATCH /api/patient/123",
+  "timestamp_utc": "2026-03-25T04:45:12.551Z",
+  "entity_type": "patient",
+  "entity_version": 7
+}
+```
 
-### logmaster
+### 5.2 Additional keys by event class
 
-**Value sets**
+- Patient/order/result mutation: `diff` (array of changed fields), `validation_profile`.
+- Import/export/jobs: `batch_id`, `record_count`, `success_count`, `failure_count`, `job_name`.
+- Auth/security events: `auth_flow`, `failure_reason`, `token_type` (never token value).
+- Retention operations: `policy_name`, `archive_id`, `approved_by`, `window_start`, `window_end`.
 
-- Create/update/retire value set items
+### 5.3 Size and shape limits
 
-**Test definitions**
+- Maximum serialized `Context` size: 16 KB.
+- `diff` array should include only audited fields, not entire entity snapshots.
+- Store references (`file_id`, `blob_ref`) instead of large payloads.
 
-- Test definition updates (units, methods, ranges)
-- Reference range changes
-- Formula/delta check changes
-- Test panel membership add/remove
+## 6) Activity and Event Catalog Governance
 
-**Infrastructure**
+`EventID` values MUST come from the ValueSet library, not hardcoded inline strings.
 
-- Analyzer/instrument config changes
-- Host app integration config
-- Coding system changes
+- Source file: `app/Libraries/Data/event_id.json`
+- Runtime access: `\App\Libraries\ValueSet::getRaw('event_id')`
+- Optional label lookup for reporting: `\App\Libraries\ValueSet::getLabel('event_id', $eventId)`
 
-**Users/roles**
+### 6.1 Allowed `ActivityID`
 
-- User create/disable/reset
-- Role changes
-- Permission changes
+`CREATE`, `UPDATE`, `DELETE`, `READ`, `MERGE`, `SPLIT`, `CANCEL`, `REOPEN`, `VERIFY`, `AMEND`, `RETRACT`, `RELEASE`, `IMPORT`, `EXPORT`, `LOGIN`, `LOGOUT`, `LOCK`, `UNLOCK`, `RESET`
 
-**Sites/workstations**
+### 6.2 `EventID` naming pattern
 
-- Site/location/workstation CRUD
+- Format: `<DOMAIN>_<OBJECT>_<ACTION>`
+- Character set: uppercase A-Z, numbers, underscore.
+- Max length: 80.
+- Examples: `PATIENT_DEMOGRAPHICS_UPDATED`, `ORDER_CANCELLED`, `AUTH_LOGIN_FAILED`.
 
-### logsystem
+### 6.3 Catalog lifecycle
 
-**Sessions & security**
+- New `EventID` requires docs update and test coverage.
+- New `EventID` must be added to `app/Libraries/Data/event_id.json` and deployed with cache refresh (`ValueSet::clearCache()`).
+- Never repurpose an existing `EventID` to mean something else.
+- Deprecated `EventID` remains queryable and documented for historical data.
 
-- Login/logout
-- Failed login attempts
-- Lockouts/password resets
-- Token issue/refresh/revoke
-- Authorization failures
+## 7) Minimum Event Coverage (Must Implement)
 
-**Import/export**
+### 7.1 `logpatient`
 
-- Import/export job start/end
-- Batch ID, source, record counts, status
+- `PATIENT_REGISTERED`, `PATIENT_DEMOGRAPHICS_UPDATED`, `PATIENT_MERGED`, `PATIENT_UNMERGED`
+- `PATIENT_IDENTIFIER_UPDATED`, `PATIENT_CONSENT_UPDATED`, `PATIENT_INSURANCE_UPDATED`
+- `VISIT_ADMITTED`, `VISIT_TRANSFERRED`, `VISIT_DISCHARGED`, `VISIT_STATUS_UPDATED`
 
-**System operations**
+### 7.2 `logorder`
 
-- Background jobs start/end
-- Integration sync runs
-- System config changes
-- Service errors that affect data integrity
+- `ORDER_CREATED`, `ORDER_CANCELLED`, `ORDER_REOPENED`, `ORDER_TEST_ADDED`, `ORDER_TEST_REMOVED`
+- `SPECIMEN_COLLECTED`, `SPECIMEN_RECEIVED`, `SPECIMEN_REJECTED`, `SPECIMEN_ALIQUOTED`, `SPECIMEN_DISPOSED`
+- `RESULT_ENTERED`, `RESULT_UPDATED`, `RESULT_VERIFIED`, `RESULT_AMENDED`, `RESULT_RELEASED`, `RESULT_RETRACTED`, `RESULT_CORRECTED`
+- `QC_RECORDED`, `QC_FAILED`, `QC_OVERRIDE_APPLIED`
 
-## Activity & Event Codes
+### 7.3 `logmaster`
 
-Use consistent `ActivityID` and `EventID` values. Recommended defaults:
+- `VALUESET_ITEM_CREATED`, `VALUESET_ITEM_UPDATED`, `VALUESET_ITEM_RETIRED`
+- `TEST_DEFINITION_UPDATED`, `REFERENCE_RANGE_UPDATED`, `TEST_PANEL_MEMBERSHIP_UPDATED`
+- `ANALYZER_CONFIG_UPDATED`, `INTEGRATION_CONFIG_UPDATED`, `CODING_SYSTEM_UPDATED`
+- `USER_CREATED`, `USER_DISABLED`, `USER_PASSWORD_RESET`, `USER_ROLE_CHANGED`, `USER_PERMISSION_CHANGED`
+- `SITE_CREATED`, `SITE_UPDATED`, `WORKSTATION_UPDATED`
 
-- `ActivityID`: `CREATE`, `UPDATE`, `DELETE`, `READ`, `MERGE`, `SPLIT`, `CANCEL`, `REOPEN`, `VERIFY`, `AMEND`, `RETRACT`, `RELEASE`, `IMPORT`, `EXPORT`, `LOGIN`, `LOGOUT`
-- `EventID`: domain-specific codes (e.g., `PATIENT_REGISTERED`, `ORDER_CREATED`, `RESULT_VERIFIED`, `QC_RECORDED`)
+### 7.4 `logsystem`
 
-## Capture Guidelines
+- `AUTH_LOGIN_SUCCESS`, `AUTH_LOGOUT_SUCCESS`, `AUTH_LOGIN_FAILED`, `AUTH_LOCKOUT_TRIGGERED`
+- `TOKEN_ISSUED`, `TOKEN_REFRESHED`, `TOKEN_REVOKED`, `AUTHORIZATION_FAILED`
+- `IMPORT_JOB_STARTED`, `IMPORT_JOB_FINISHED`, `EXPORT_JOB_STARTED`, `EXPORT_JOB_FINISHED`
+- `JOB_STARTED`, `JOB_FINISHED`, `INTEGRATION_SYNC_STARTED`, `INTEGRATION_SYNC_FINISHED`
+- `AUDIT_ARCHIVE_EXECUTED`, `AUDIT_PURGE_EXECUTED`, `LEGAL_HOLD_APPLIED`, `LEGAL_HOLD_RELEASED`
 
-- Always capture `UserID`, `SessionID`, `SiteID`, and `LogDate` when available.
-- If the action is system-driven, set `UserID` to `SYSTEM` (or null) and add context in `Context`.
-- Store payload diffs in `FldValuePrev` and `FldValueNew` for single-field changes; for multi-field changes, put a JSON diff in `Context` and leave `FldName` null.
-- For bulk operations, store batch metadata in `Context` (`batch_id`, `record_count`, `source`).
-- Do not log secrets, tokens, or full PHI when not required. Mask or omit sensitive fields.
+## 8) Capture Rules (Application Behavior)
 
-## Retention & Governance
+### 8.1 Write timing
 
-- Define retention policy per table (e.g., 7 years for patient/order, 2 years for system).
-- Archive before purge; record purge activity in `logsystem`.
-- Restrict write/delete permissions to service accounts only.
+- For mutating transactions, write audit record in the same DB transaction where feasible.
+- If asynchronous logging is required, enqueue within transaction and process with at-least-once delivery.
 
-## Implementation Checklist
+### 8.2 Failure policy
 
-1. Create the four tables with shared schema (or migrate existing log tables to match).
-2. Add a single audit service with helpers to build a normalized payload.
-3. Instrument controllers/services for each event category above.
-4. Add automated tests for representative audit writes.
-5. Document `EventID` codes used by each endpoint/service.
+- Compliance-critical writes (patient, order, result, role/permission): fail request if audit write fails.
+- Operational-only writes (non-critical job checkpoints): continue request, emit error log, retry in background.
+- All audit write failures must produce `logsystem` event `AUDIT_WRITE_FAILED` with sanitized details.
+
+### 8.3 Diff policy
+
+- Single-field change: set `FldName`, `FldValuePrev`, `FldValueNew`.
+- Multi-field change: set `FldName = NULL`, keep prev/new null or compact summary, place canonical diff in `Context.diff`.
+- Bulk operations: include `batch_id`, `record_count`, sample `affected_ids` (capped), and source.
+
+## 9) Security and Privacy Controls
+
+### 9.1 Never log
+
+- Passwords, raw JWTs, API secrets, private keys, OTP values.
+- Full clinical free text unless explicitly required by policy.
+
+### 9.2 Masking rules
+
+- Identifiers with high sensitivity should be masked in `FldValuePrev/New` when not required.
+- Token-like strings should be fully removed and replaced with `[REDACTED]`.
+- Use deterministic masking where correlation is needed (e.g., hash + prefix).
+
+### 9.3 Access control
+
+- Insert permissions only for API/service accounts.
+- No update/delete privileges for regular runtime users.
+- Read access to logs is role-restricted and audited.
+
+### 9.4 Tamper evidence
+
+- Enable DB audit on DDL changes to log tables.
+- Store periodic checksum snapshots of recent log ranges in secure storage.
+- Record checksum run outcomes in `logsystem` (`AUDIT_CHECKSUM_CREATED`, `AUDIT_CHECKSUM_FAILED`).
+
+## 10) Retention, Archive, and Purge
+
+### 10.1 Default retention
+
+- `logpatient`: 7 years
+- `logorder`: 7 years
+- `logmaster`: 5 years
+- `logsystem`: 2 years
+
+If regional policy requires longer periods, policy overrides these defaults.
+
+### 10.2 Archive workflow
+
+1. Select eligible rows by `LogDate` and legal-hold status.
+2. Export to immutable archive format (compressed JSONL or parquet).
+3. Verify checksums and row counts.
+4. Write `AUDIT_ARCHIVE_EXECUTED` entry in `logsystem`.
+
+### 10.3 Purge workflow
+
+1. Require approval reference (`approved_by`, `change_ticket`).
+2. Purge archived rows only.
+3. Write `AUDIT_PURGE_EXECUTED` entry with table, date window, count, and archive reference.
+
+## 11) Operational Monitoring
+
+Track these SLIs/SLOs:
+
+- Audit write success rate >= 99.9% for critical domains.
+- P95 audit insert latency < 50 ms.
+- Queue backlog age < 5 minutes (if async path is used).
+- Zero unreviewed `AUDIT_WRITE_FAILED` older than 24 hours.
+
+Alert on:
+
+- Sustained write failures.
+- Sudden drop in expected event volume.
+- Purge/archive jobs without corresponding `logsystem` records.
+
+## 12) Migration Strategy for Existing Logs
+
+1. Inventory current columns and event vocabulary in all four tables.
+2. Add missing canonical columns with nullable defaults.
+3. Backfill required values (`AppID`, `SessionID`, `Context` minimum keys) where derivable.
+4. Introduce canonical `EventID` mapping table for legacy names.
+5. Enforce NOT NULL constraints only after backfill validation succeeds.
+
+## 13) Testing Requirements
+
+### 13.1 Automated tests
+
+- Feature tests for representative endpoints must assert audit row creation.
+- Assert table target, `ActivityID`, `EventID`, `RecID`, and required `Context` keys.
+- Assert `EventID` exists in `\App\Libraries\ValueSet::getRaw('event_id')`.
+- Add negative tests for audit failure policy (critical path blocks, non-critical path retries).
+
+### 13.2 Test matrix minimum
+
+- One success and one failure scenario per major domain (`patient`, `order`, `master`, `system`).
+- One bulk operation scenario validating `batch_id` and counts.
+- One security scenario validating redaction of sensitive fields.
+
+## 14) Implementation Checklist (Phased)
+
+### Phase 1 - Schema and constants
+
+1. Create/align all four log tables to canonical schema.
+2. Add shared enums/constants for `ActivityID` and `EventID`.
+3. Add and maintain `app/Libraries/Data/event_id.json` as the `EventID` source of truth.
+4. Add DB indexes listed in section 4.
+
+### Phase 2 - Audit service
+
+1. Implement centralized audit writer service.
+2. Add helpers to normalize actor/device/session/context.
+3. Add diff builder utility for single and multi-field changes.
+
+### Phase 3 - Instrumentation
+
+1. Instrument patient and order flows first (compliance-critical).
+2. Instrument master and system flows.
+3. Add fallback/retry path and `AUDIT_WRITE_FAILED` emission.
+
+### Phase 4 - Validation and rollout
+
+1. Add feature tests and failure-path tests.
+2. Validate dashboards/queries for each table.
+3. Release with runbook updates and retention job schedule.
+
+## 15) Acceptance Criteria
+
+The implementation is complete when all statements below are true:
+
+- Every protected endpoint emits at least one canonical audit row.
+- Each row has valid `ActivityID`, `EventID` (present in ValueSet `event_id`), `LogDate` (UTC), and non-empty `Context` with required keys.
+- Sensitive values are redacted/masked per section 9.
+- Archive and purge operations are fully traceable in `logsystem`.
+- Tests cover critical success/failure paths and pass in CI.
diff --git a/public/api-docs.bundled.yaml b/public/api-docs.bundled.yaml
index 3ce3e13..5e573c8 100644
--- a/public/api-docs.bundled.yaml
+++ b/public/api-docs.bundled.yaml
@@ -4447,16 +4447,55 @@ paths:
                 properties:
                   status:
                     type: string
+                  message:
+                    type: string
                   data:
                     type: array
                     items:
-                      $ref: '#/components/schemas/TestDefinition'
+                      $ref: '#/components/schemas/TestDefinitionListItem'
                   pagination:
                     type: object
                     properties:
                       total:
                         type: integer
                         description: Total number of records matching the query
+              examples:
+                list_flat:
+                  summary: Flat list response from testdefsite
+                  value:
+                    status: success
+                    message: Data fetched successfully
+                    data:
+                      - TestSiteID: 21
+                        TestSiteCode: GLU
+                        TestSiteName: Glucose
+                        TestType: TEST
+                        SeqScr: 11
+                        SeqRpt: 11
+                        VisibleScr: 1
+                        VisibleRpt: 1
+                        CountStat: 1
+                        StartDate: '2026-01-01 00:00:00'
+                        EndDate: null
+                        DisciplineID: 2
+                        DepartmentID: 2
+                        DisciplineName: Clinical Chemistry
+                        DepartmentName: Laboratory
+                      - TestSiteID: 22
+                        TestSiteCode: CREA
+                        TestSiteName: Creatinine
+                        TestType: TEST
+                        SeqScr: 12
+                        SeqRpt: 12
+                        VisibleScr: 1
+                        VisibleRpt: 1
+                        CountStat: 1
+                        StartDate: '2026-01-01 00:00:00'
+                        EndDate: null
+                        DisciplineID: 2
+                        DepartmentID: 2
+                        DisciplineName: Clinical Chemistry
+                        DepartmentName: Laboratory
     post:
       tags:
         - Test
@@ -4546,62 +4585,26 @@ paths:
                   type: integer
                 CountStat:
                   type: integer
-                details:
+                testdefcal:
                   type: object
-                  description: |
-                    Type-specific details. For CALC and GROUP types, include members array.
-
-                    **Important**: Members must use `TestSiteID` (the actual test ID), NOT `Member` or `SeqScr`.
-                    Invalid TestSiteIDs will result in a 400 error.
+                  description: Calculated test metadata persisted in the `testdefcal` table.
                   properties:
-                    DisciplineID:
-                      type: integer
-                    DepartmentID:
-                      type: integer
-                    ResultType:
-                      type: string
-                      enum:
-                        - NMRIC
-                        - RANGE
-                        - TEXT
-                        - VSET
-                        - NORES
-                    RefType:
-                      type: string
-                      enum:
-                        - RANGE
-                        - THOLD
-                        - VSET
-                        - TEXT
-                        - NOREF
                     FormulaCode:
                       type: string
-                      description: Formula expression for CALC type (e.g., "{TBIL} - {DBIL}")
-                    Unit1:
-                      type: string
-                    Factor:
-                      type: number
-                    Unit2:
-                      type: string
-                    Decimal:
-                      type: integer
-                      default: 2
-                    Method:
-                      type: string
-                    ExpectedTAT:
-                      type: integer
+                      description: Formula expression for calculated tests (e.g., "{TBIL} - {DBIL}")
+                testdefgrp:
+                  type: object
+                  description: Group member payload stored in the `testdefgrp` table.
+                  properties:
                     members:
                       type: array
-                      description: |
-                        Array of member tests for CALC and GROUP types.
-                        Each member object must contain `TestSiteID` (the actual test ID).
-                        Do NOT use `Member` or `SeqScr` - these will be rejected with validation error.
+                      description: Array of member TestSiteIDs for CALC/GROUP definitions.
                       items:
                         type: object
                         properties:
                           TestSiteID:
                             type: integer
-                            description: The actual TestSiteID of the member test (required)
+                            description: Foreign key referencing the member test's TestSiteID.
                         required:
                           - TestSiteID
                 refnum:
@@ -4634,11 +4637,10 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    DisciplineID: 2
-                    DepartmentID: 2
-                    Unit1: mg/dL
-                    Method: CBC Analyzer
+                  DisciplineID: 2
+                  DepartmentID: 2
+                  Unit1: mg/dL
+                  Method: CBC Analyzer
               PARAM_no_ref:
                 summary: Parameter without reference or map
                 value:
@@ -4651,11 +4653,10 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 0
                   CountStat: 0
-                  details:
-                    DisciplineID: 10
-                    DepartmentID: 0
-                    Unit1: cm
-                    Method: Manual entry
+                  DisciplineID: 10
+                  DepartmentID: 0
+                  Unit1: cm
+                  Method: Manual entry
               TEST_range_single:
                 summary: Technical test with numeric range reference (single)
                 value:
@@ -4668,13 +4669,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    DisciplineID: 2
-                    DepartmentID: 2
-                    ResultType: NMRIC
-                    RefType: RANGE
-                    Unit1: mg/dL
-                    Method: Hexokinase
                   refnum:
                     - NumRefType: NMRC
                       RangeType: REF
@@ -4686,6 +4680,12 @@ paths:
                       AgeStart: 18
                       AgeEnd: 99
                       Flag: 'N'
+                  DisciplineID: 2
+                  DepartmentID: 2
+                  ResultType: NMRIC
+                  RefType: RANGE
+                  Unit1: mg/dL
+                  Method: Hexokinase
               TEST_range_multiple_map:
                 summary: Numeric reference with multiple ranges and test map
                 value:
@@ -4698,13 +4698,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    DisciplineID: 2
-                    DepartmentID: 2
-                    ResultType: NMRIC
-                    RefType: RANGE
-                    Unit1: mg/dL
-                    Method: Hexokinase
                   refnum:
                     - NumRefType: NMRC
                       RangeType: REF
@@ -4752,6 +4745,12 @@ paths:
                           ConDefID: 3
                           ClientTestCode: HB_C
                           ClientTestName: Hemoglobin Client
+                  DisciplineID: 2
+                  DepartmentID: 2
+                  ResultType: NMRIC
+                  RefType: RANGE
+                  Unit1: mg/dL
+                  Method: Hexokinase
               TEST_threshold:
                 summary: Technical test with threshold reference
                 value:
@@ -4764,13 +4763,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    DisciplineID: 2
-                    DepartmentID: 2
-                    ResultType: NMRIC
-                    RefType: THOLD
-                    Unit1: mmol/L
-                    Method: Auto Analyzer
                   refnum:
                     - NumRefType: THOLD
                       RangeType: PANIC
@@ -4780,6 +4772,12 @@ paths:
                       AgeStart: 0
                       AgeEnd: 125
                       Flag: H
+                  DisciplineID: 2
+                  DepartmentID: 2
+                  ResultType: NMRIC
+                  RefType: THOLD
+                  Unit1: mmol/L
+                  Method: Auto Analyzer
               TEST_threshold_map:
                 summary: Threshold reference plus test map
                 value:
@@ -4792,13 +4790,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    DisciplineID: 2
-                    DepartmentID: 2
-                    ResultType: NMRIC
-                    RefType: THOLD
-                    Unit1: mmol/L
-                    Method: Auto Analyzer
                   refnum:
                     - NumRefType: THOLD
                       RangeType: PANIC
@@ -4832,6 +4823,12 @@ paths:
                           ConDefID: 1
                           ClientTestCode: GLU_C
                           ClientTestName: Glucose Client
+                  DisciplineID: 2
+                  DepartmentID: 2
+                  ResultType: NMRIC
+                  RefType: THOLD
+                  Unit1: mmol/L
+                  Method: Auto Analyzer
               TEST_text:
                 summary: Technical test with text reference
                 value:
@@ -4844,12 +4841,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    DisciplineID: 1
-                    DepartmentID: 1
-                    ResultType: TEXT
-                    RefType: TEXT
-                    Method: Morphology
                   reftxt:
                     - SpcType: GEN
                       TxtRefType: TEXT
@@ -4858,6 +4849,11 @@ paths:
                       AgeEnd: 99
                       RefTxt: NORM=Normal;HIGH=High
                       Flag: 'N'
+                  DisciplineID: 1
+                  DepartmentID: 1
+                  ResultType: TEXT
+                  RefType: TEXT
+                  Method: Morphology
               TEST_text_map:
                 summary: Text reference plus test map
                 value:
@@ -4870,11 +4866,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    DisciplineID: 1
-                    DepartmentID: 1
-                    ResultType: TEXT
-                    RefType: TEXT
                   reftxt:
                     - SpcType: GEN
                       TxtRefType: TEXT
@@ -4901,6 +4892,10 @@ paths:
                           ConDefID: 4
                           ClientTestCode: STAGE_C
                           ClientTestName: Disease Stage Client
+                  DisciplineID: 1
+                  DepartmentID: 1
+                  ResultType: TEXT
+                  RefType: TEXT
               TEST_valueset:
                 summary: Technical test using a value set result
                 value:
@@ -4913,12 +4908,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    DisciplineID: 4
-                    DepartmentID: 4
-                    ResultType: VSET
-                    RefType: VSET
-                    Method: Visual
                   reftxt:
                     - SpcType: GEN
                       TxtRefType: VSET
@@ -4927,6 +4916,11 @@ paths:
                       AgeEnd: 120
                       RefTxt: NORM=Normal;MACRO=Macro
                       Flag: 'N'
+                  DisciplineID: 4
+                  DepartmentID: 4
+                  ResultType: VSET
+                  RefType: VSET
+                  Method: Visual
               TEST_valueset_map:
                 summary: Value set reference with test map
                 value:
@@ -4939,11 +4933,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    DisciplineID: 4
-                    DepartmentID: 4
-                    ResultType: VSET
-                    RefType: VSET
                   reftxt:
                     - SpcType: GEN
                       TxtRefType: VSET
@@ -4963,6 +4952,10 @@ paths:
                           ConDefID: 12
                           ClientTestCode: UCOLOR_C
                           ClientTestName: Urine Color Client
+                  DisciplineID: 4
+                  DepartmentID: 4
+                  ResultType: VSET
+                  RefType: VSET
               TEST_valueset_map_no_reftxt:
                 summary: Value set result with mapping but without explicit text reference entries
                 value:
@@ -4975,11 +4968,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    DisciplineID: 4
-                    DepartmentID: 4
-                    ResultType: VSET
-                    RefType: VSET
                   testmap:
                     - HostType: SITE
                       HostID: '1'
@@ -4991,6 +4979,10 @@ paths:
                           ConDefID: 12
                           ClientTestCode: UGLUC_C
                           ClientTestName: Urine Glucose Client
+                  DisciplineID: 4
+                  DepartmentID: 4
+                  ResultType: VSET
+                  RefType: VSET
               CALC_basic:
                 summary: Calculated test with members (no references)
                 value:
@@ -5003,10 +4995,11 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 0
-                  details:
-                    DisciplineID: 2
-                    DepartmentID: 2
+                  DisciplineID: 2
+                  DepartmentID: 2
+                  testdefcal:
                     FormulaCode: CKD_EPI(CREA,AGE,GENDER)
+                  testdefgrp:
                     members:
                       - TestSiteID: 21
                       - TestSiteID: 22
@@ -5022,13 +5015,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 0
-                  details:
-                    DisciplineID: 2
-                    DepartmentID: 2
-                    FormulaCode: CKD_EPI(CREA,AGE,GENDER)
-                    members:
-                      - TestSiteID: 21
-                      - TestSiteID: 22
                   refnum:
                     - NumRefType: NMRC
                       RangeType: REF
@@ -5051,6 +5037,14 @@ paths:
                           ConDefID: 1
                           ClientTestCode: EGFR_C
                           ClientTestName: eGFR Client
+                  DisciplineID: 2
+                  DepartmentID: 2
+                  testdefcal:
+                    FormulaCode: CKD_EPI(CREA,AGE,GENDER)
+                  testdefgrp:
+                    members:
+                      - TestSiteID: 21
+                      - TestSiteID: 22
               GROUP_with_members:
                 summary: Group/profile test with members and mapping
                 value:
@@ -5063,10 +5057,6 @@ paths:
                   VisibleScr: 1
                   VisibleRpt: 1
                   CountStat: 1
-                  details:
-                    members:
-                      - TestSiteID: 169
-                      - TestSiteID: 170
                   testmap:
                     - HostType: SITE
                       HostID: '1'
@@ -5078,6 +5068,10 @@ paths:
                           ConDefID: 1
                           ClientTestCode: LIPID_C
                           ClientTestName: Lipid Client
+                  testdefgrp:
+                    members:
+                      - TestSiteID: 169
+                      - TestSiteID: 170
       responses:
         '201':
           description: Test definition created
@@ -5195,62 +5189,26 @@ paths:
                   type: integer
                 CountStat:
                   type: integer
-                details:
+                testdefcal:
                   type: object
-                  description: |
-                    Type-specific details. For CALC and GROUP types, include members array.
-
-                    **Important**: Members must use `TestSiteID` (the actual test ID), NOT `Member` or `SeqScr`.
-                    Invalid TestSiteIDs will result in a 400 error.
+                  description: Calculated test metadata persisted in the `testdefcal` table.
                   properties:
-                    DisciplineID:
-                      type: integer
-                    DepartmentID:
-                      type: integer
-                    ResultType:
-                      type: string
-                      enum:
-                        - NMRIC
-                        - RANGE
-                        - TEXT
-                        - VSET
-                        - NORES
-                    RefType:
-                      type: string
-                      enum:
-                        - RANGE
-                        - THOLD
-                        - VSET
-                        - TEXT
-                        - NOREF
                     FormulaCode:
                       type: string
-                      description: Formula expression for CALC type (e.g., "{TBIL} - {DBIL}")
-                    Unit1:
-                      type: string
-                    Factor:
-                      type: number
-                    Unit2:
-                      type: string
-                    Decimal:
-                      type: integer
-                      default: 2
-                    Method:
-                      type: string
-                    ExpectedTAT:
-                      type: integer
+                      description: Formula expression for calculated tests (e.g., "{TBIL} - {DBIL}")
+                testdefgrp:
+                  type: object
+                  description: Group member payload stored in the `testdefgrp` table.
+                  properties:
                     members:
                       type: array
-                      description: |
-                        Array of member tests for CALC and GROUP types.
-                        Each member object must contain `TestSiteID` (the actual test ID).
-                        Do NOT use `Member` or `SeqScr` - these will be rejected with validation error.
+                      description: Array of member TestSiteIDs for CALC/GROUP definitions.
                       items:
                         type: object
                         properties:
                           TestSiteID:
                             type: integer
-                            description: The actual TestSiteID of the member test (required)
+                            description: Foreign key referencing the member test's TestSiteID.
                         required:
                           - TestSiteID
                 refnum:
@@ -8122,6 +8080,58 @@ components:
           type: string
           format: date-time
           description: Soft delete timestamp
+    TestDefinitionListItem:
+      type: object
+      properties:
+        TestSiteID:
+          type: integer
+        TestSiteCode:
+          type: string
+        TestSiteName:
+          type: string
+        TestType:
+          type: string
+          enum:
+            - TEST
+            - PARAM
+            - CALC
+            - GROUP
+            - TITLE
+        SeqScr:
+          type: integer
+        SeqRpt:
+          type: integer
+        VisibleScr:
+          type: integer
+          enum:
+            - 0
+            - 1
+        VisibleRpt:
+          type: integer
+          enum:
+            - 0
+            - 1
+        CountStat:
+          type: integer
+        StartDate:
+          type: string
+          format: date-time
+        EndDate:
+          type: string
+          format: date-time
+          nullable: true
+        DisciplineID:
+          type: integer
+          nullable: true
+        DepartmentID:
+          type: integer
+          nullable: true
+        DisciplineName:
+          type: string
+          nullable: true
+        DepartmentName:
+          type: string
+          nullable: true
     ValueSetListItem:
       type: object
       description: Library/system value set summary (from JSON files)
diff --git a/public/components/schemas/tests.yaml b/public/components/schemas/tests.yaml
index 630956e..6710bfb 100644
--- a/public/components/schemas/tests.yaml
+++ b/public/components/schemas/tests.yaml
@@ -1,4 +1,48 @@
-TestDefinition:
+TestDefinitionListItem:
+  type: object
+  properties:
+    TestSiteID:
+      type: integer
+    TestSiteCode:
+      type: string
+    TestSiteName:
+      type: string
+    TestType:
+      type: string
+      enum: [TEST, PARAM, CALC, GROUP, TITLE]
+    SeqScr:
+      type: integer
+    SeqRpt:
+      type: integer
+    VisibleScr:
+      type: integer
+      enum: [0, 1]
+    VisibleRpt:
+      type: integer
+      enum: [0, 1]
+    CountStat:
+      type: integer
+    StartDate:
+      type: string
+      format: date-time
+    EndDate:
+      type: string
+      format: date-time
+      nullable: true
+    DisciplineID:
+      type: integer
+      nullable: true
+    DepartmentID:
+      type: integer
+      nullable: true
+    DisciplineName:
+      type: string
+      nullable: true
+    DepartmentName:
+      type: string
+      nullable: true
+
+TestDefinition:
   type: object
   properties:
     TestSiteID:
diff --git a/public/paths/tests.yaml b/public/paths/tests.yaml
index 2e0eeea..59c0605 100644
--- a/public/paths/tests.yaml
+++ b/public/paths/tests.yaml
@@ -53,18 +53,57 @@
             schema:
               type: object
               properties:
-                status:
-                  type: string
-                data:
-                  type: array
-                  items:
-                    $ref: '../components/schemas/tests.yaml#/TestDefinition'
-                pagination:
-                  type: object
-                  properties:
-                    total:
-                      type: integer
-                      description: Total number of records matching the query
+                status:
+                  type: string
+                message:
+                  type: string
+                data:
+                  type: array
+                  items:
+                    $ref: '../components/schemas/tests.yaml#/TestDefinitionListItem'
+                pagination:
+                  type: object
+                  properties:
+                    total:
+                      type: integer
+                      description: Total number of records matching the query
+            examples:
+              list_flat:
+                summary: Flat list response from testdefsite
+                value:
+                  status: success
+                  message: Data fetched successfully
+                  data:
+                    - TestSiteID: 21
+                      TestSiteCode: GLU
+                      TestSiteName: Glucose
+                      TestType: TEST
+                      SeqScr: 11
+                      SeqRpt: 11
+                      VisibleScr: 1
+                      VisibleRpt: 1
+                      CountStat: 1
+                      StartDate: '2026-01-01 00:00:00'
+                      EndDate: null
+                      DisciplineID: 2
+                      DepartmentID: 2
+                      DisciplineName: Clinical Chemistry
+                      DepartmentName: Laboratory
+                    - TestSiteID: 22
+                      TestSiteCode: CREA
+                      TestSiteName: Creatinine
+                      TestType: TEST
+                      SeqScr: 12
+                      SeqRpt: 12
+                      VisibleScr: 1
+                      VisibleRpt: 1
+                      CountStat: 1
+                      StartDate: '2026-01-01 00:00:00'
+                      EndDate: null
+                      DisciplineID: 2
+                      DepartmentID: 2
+                      DisciplineName: Clinical Chemistry
+                      DepartmentName: Laboratory
 
   post:
     tags: [Test]
@@ -137,56 +176,30 @@
                 type: integer
               VisibleRpt:
                 type: integer
-              CountStat:
-                type: integer
-              details:
-                type: object
-                description: |
-                  Type-specific details. For CALC and GROUP types, include members array.
-                  
-                  **Important**: Members must use `TestSiteID` (the actual test ID), NOT `Member` or `SeqScr`.
-                  Invalid TestSiteIDs will result in a 400 error.
-                properties:
-                  DisciplineID:
-                    type: integer
-                  DepartmentID:
-                    type: integer
-                  ResultType:
-                    type: string
-                    enum: [NMRIC, RANGE, TEXT, VSET, NORES]
-                  RefType:
-                    type: string
-                    enum: [RANGE, THOLD, VSET, TEXT, NOREF]
-                  FormulaCode:
-                    type: string
-                    description: Formula expression for CALC type (e.g., "{TBIL} - {DBIL}")
-                  Unit1:
-                    type: string
-                  Factor:
-                    type: number
-                  Unit2:
-                    type: string
-                  Decimal:
-                    type: integer
-                    default: 2
-                  Method:
-                    type: string
-                  ExpectedTAT:
-                    type: integer
-                  members:
-                    type: array
-                    description: |
-                      Array of member tests for CALC and GROUP types.
-                      Each member object must contain `TestSiteID` (the actual test ID).
-                      Do NOT use `Member` or `SeqScr` - these will be rejected with validation error.
-                    items:
-                      type: object
-                      properties:
-                        TestSiteID:
-                          type: integer
-                          description: The actual TestSiteID of the member test (required)
-                      required:
-                        - TestSiteID
+              CountStat:
+                type: integer
+              testdefcal:
+                type: object
+                description: Calculated test metadata persisted in the `testdefcal` table.
+                properties:
+                  FormulaCode:
+                    type: string
+                    description: Formula expression for calculated tests (e.g., "{TBIL} - {DBIL}")
+              testdefgrp:
+                type: object
+                description: Group member payload stored in the `testdefgrp` table.
+                properties:
+                  members:
+                    type: array
+                    description: Array of member TestSiteIDs for CALC/GROUP definitions.
+                    items:
+                      type: object
+                      properties:
+                        TestSiteID:
+                          type: integer
+                          description: Foreign key referencing the member test's TestSiteID.
+                      required:
+                        - TestSiteID
               refnum:
                 type: array
                 items:
@@ -217,11 +230,10 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  DisciplineID: 2
-                  DepartmentID: 2
-                  Unit1: mg/dL
-                  Method: CBC Analyzer
+                DisciplineID: 2
+                DepartmentID: 2
+                Unit1: mg/dL
+                Method: CBC Analyzer
             PARAM_no_ref:
               summary: Parameter without reference or map
               value:
@@ -234,11 +246,10 @@
                 VisibleScr: 1
                 VisibleRpt: 0
                 CountStat: 0
-                details:
-                  DisciplineID: 10
-                  DepartmentID: 0
-                  Unit1: cm
-                  Method: Manual entry
+                DisciplineID: 10
+                DepartmentID: 0
+                Unit1: cm
+                Method: Manual entry
             TEST_range_single:
               summary: Technical test with numeric range reference (single)
               value:
@@ -251,13 +262,6 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  DisciplineID: 2
-                  DepartmentID: 2
-                  ResultType: NMRIC
-                  RefType: RANGE
-                  Unit1: mg/dL
-                  Method: Hexokinase
                 refnum:
                   - NumRefType: NMRC
                     RangeType: REF
@@ -269,6 +273,12 @@
                     AgeStart: 18
                     AgeEnd: 99
                     Flag: N
+                DisciplineID: 2
+                DepartmentID: 2
+                ResultType: NMRIC
+                RefType: RANGE
+                Unit1: mg/dL
+                Method: Hexokinase
             TEST_range_multiple_map:
               summary: Numeric reference with multiple ranges and test map
               value:
@@ -281,13 +291,6 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  DisciplineID: 2
-                  DepartmentID: 2
-                  ResultType: NMRIC
-                  RefType: RANGE
-                  Unit1: mg/dL
-                  Method: Hexokinase
                 refnum:
                   - NumRefType: NMRC
                     RangeType: REF
@@ -304,7 +307,7 @@
                     Sex: '1'
                     LowSign: '>'
                     Low: 75
-                    HighSign: '<'
+                    HighSign: <
                     High: 105
                     AgeStart: 18
                     AgeEnd: 99
@@ -335,6 +338,12 @@
                         ConDefID: 3
                         ClientTestCode: HB_C
                         ClientTestName: Hemoglobin Client
+                DisciplineID: 2
+                DepartmentID: 2
+                ResultType: NMRIC
+                RefType: RANGE
+                Unit1: mg/dL
+                Method: Hexokinase
             TEST_threshold:
               summary: Technical test with threshold reference
               value:
@@ -347,13 +356,6 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  DisciplineID: 2
-                  DepartmentID: 2
-                  ResultType: NMRIC
-                  RefType: THOLD
-                  Unit1: mmol/L
-                  Method: Auto Analyzer
                 refnum:
                   - NumRefType: THOLD
                     RangeType: PANIC
@@ -363,6 +365,12 @@
                     AgeStart: 0
                     AgeEnd: 125
                     Flag: H
+                DisciplineID: 2
+                DepartmentID: 2
+                ResultType: NMRIC
+                RefType: THOLD
+                Unit1: mmol/L
+                Method: Auto Analyzer
             TEST_threshold_map:
               summary: Threshold reference plus test map
               value:
@@ -375,13 +383,6 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  DisciplineID: 2
-                  DepartmentID: 2
-                  ResultType: NMRIC
-                  RefType: THOLD
-                  Unit1: mmol/L
-                  Method: Auto Analyzer
                 refnum:
                   - NumRefType: THOLD
                     RangeType: PANIC
@@ -394,7 +395,7 @@
                   - NumRefType: THOLD
                     RangeType: PANIC
                     Sex: '1'
-                    LowSign: '<'
+                    LowSign: <
                     Low: 121
                     AgeStart: 0
                     AgeEnd: 125
@@ -415,6 +416,12 @@
                         ConDefID: 1
                         ClientTestCode: GLU_C
                         ClientTestName: Glucose Client
+                DisciplineID: 2
+                DepartmentID: 2
+                ResultType: NMRIC
+                RefType: THOLD
+                Unit1: mmol/L
+                Method: Auto Analyzer
             TEST_text:
               summary: Technical test with text reference
               value:
@@ -427,20 +434,19 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  DisciplineID: 1
-                  DepartmentID: 1
-                  ResultType: TEXT
-                  RefType: TEXT
-                  Method: Morphology
                 reftxt:
                   - SpcType: GEN
                     TxtRefType: TEXT
                     Sex: '2'
                     AgeStart: 18
                     AgeEnd: 99
-                    RefTxt: 'NORM=Normal;HIGH=High'
+                    RefTxt: NORM=Normal;HIGH=High
                     Flag: N
+                DisciplineID: 1
+                DepartmentID: 1
+                ResultType: TEXT
+                RefType: TEXT
+                Method: Morphology
             TEST_text_map:
               summary: Text reference plus test map
               value:
@@ -453,25 +459,20 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  DisciplineID: 1
-                  DepartmentID: 1
-                  ResultType: TEXT
-                  RefType: TEXT
                 reftxt:
                   - SpcType: GEN
                     TxtRefType: TEXT
                     Sex: '2'
                     AgeStart: 18
                     AgeEnd: 99
-                    RefTxt: 'NORM=Normal'
+                    RefTxt: NORM=Normal
                     Flag: N
                   - SpcType: GEN
                     TxtRefType: TEXT
                     Sex: '1'
                     AgeStart: 18
                     AgeEnd: 99
-                    RefTxt: 'ABN=Abnormal'
+                    RefTxt: ABN=Abnormal
                     Flag: N
                 testmap:
                   - HostType: SITE
@@ -484,6 +485,10 @@
                         ConDefID: 4
                         ClientTestCode: STAGE_C
                         ClientTestName: Disease Stage Client
+                DisciplineID: 1
+                DepartmentID: 1
+                ResultType: TEXT
+                RefType: TEXT
             TEST_valueset:
               summary: Technical test using a value set result
               value:
@@ -496,20 +501,19 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  DisciplineID: 4
-                  DepartmentID: 4
-                  ResultType: VSET
-                  RefType: VSET
-                  Method: Visual
                 reftxt:
                   - SpcType: GEN
                     TxtRefType: VSET
                     Sex: '2'
                     AgeStart: 0
                     AgeEnd: 120
-                    RefTxt: 'NORM=Normal;MACRO=Macro'
+                    RefTxt: NORM=Normal;MACRO=Macro
                     Flag: N
+                DisciplineID: 4
+                DepartmentID: 4
+                ResultType: VSET
+                RefType: VSET
+                Method: Visual
             TEST_valueset_map:
               summary: Value set reference with test map
               value:
@@ -522,18 +526,13 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  DisciplineID: 4
-                  DepartmentID: 4
-                  ResultType: VSET
-                  RefType: VSET
                 reftxt:
                   - SpcType: GEN
                     TxtRefType: VSET
                     Sex: '2'
                     AgeStart: 0
                     AgeEnd: 120
-                    RefTxt: 'NORM=Normal;ABN=Abnormal'
+                    RefTxt: NORM=Normal;ABN=Abnormal
                     Flag: N
                 testmap:
                   - HostType: SITE
@@ -546,6 +545,10 @@
                         ConDefID: 12
                         ClientTestCode: UCOLOR_C
                         ClientTestName: Urine Color Client
+                DisciplineID: 4
+                DepartmentID: 4
+                ResultType: VSET
+                RefType: VSET
             TEST_valueset_map_no_reftxt:
               summary: Value set result with mapping but without explicit text reference entries
               value:
@@ -558,11 +561,6 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  DisciplineID: 4
-                  DepartmentID: 4
-                  ResultType: VSET
-                  RefType: VSET
                 testmap:
                   - HostType: SITE
                     HostID: '1'
@@ -574,6 +572,10 @@
                         ConDefID: 12
                         ClientTestCode: UGLUC_C
                         ClientTestName: Urine Glucose Client
+                DisciplineID: 4
+                DepartmentID: 4
+                ResultType: VSET
+                RefType: VSET
             CALC_basic:
               summary: Calculated test with members (no references)
               value:
@@ -586,10 +588,11 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 0
-                details:
-                  DisciplineID: 2
-                  DepartmentID: 2
+                DisciplineID: 2
+                DepartmentID: 2
+                testdefcal:
                   FormulaCode: CKD_EPI(CREA,AGE,GENDER)
+                testdefgrp:
                   members:
                     - TestSiteID: 21
                     - TestSiteID: 22
@@ -605,13 +608,6 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 0
-                details:
-                  DisciplineID: 2
-                  DepartmentID: 2
-                  FormulaCode: CKD_EPI(CREA,AGE,GENDER)
-                  members:
-                    - TestSiteID: 21
-                    - TestSiteID: 22
                 refnum:
                   - NumRefType: NMRC
                     RangeType: REF
@@ -634,6 +630,14 @@
                         ConDefID: 1
                         ClientTestCode: EGFR_C
                         ClientTestName: eGFR Client
+                DisciplineID: 2
+                DepartmentID: 2
+                testdefcal:
+                  FormulaCode: CKD_EPI(CREA,AGE,GENDER)
+                testdefgrp:
+                  members:
+                    - TestSiteID: 21
+                    - TestSiteID: 22
             GROUP_with_members:
               summary: Group/profile test with members and mapping
               value:
@@ -646,10 +650,6 @@
                 VisibleScr: 1
                 VisibleRpt: 1
                 CountStat: 1
-                details:
-                  members:
-                    - TestSiteID: 169
-                    - TestSiteID: 170
                 testmap:
                   - HostType: SITE
                     HostID: '1'
@@ -661,6 +661,11 @@
                         ConDefID: 1
                         ClientTestCode: LIPID_C
                         ClientTestName: Lipid Client
+                testdefgrp:
+                  members:
+                    - TestSiteID: 169
+                    - TestSiteID: 170
+
     responses:
       '201':
         description: Test definition created
@@ -761,56 +766,30 @@
                 type: integer
               VisibleRpt:
                 type: integer
-              CountStat:
-                type: integer
-              details:
-                type: object
-                description: |
-                  Type-specific details. For CALC and GROUP types, include members array.
-                  
-                  **Important**: Members must use `TestSiteID` (the actual test ID), NOT `Member` or `SeqScr`.
-                  Invalid TestSiteIDs will result in a 400 error.
-                properties:
-                  DisciplineID:
-                    type: integer
-                  DepartmentID:
-                    type: integer
-                  ResultType:
-                    type: string
-                    enum: [NMRIC, RANGE, TEXT, VSET, NORES]
-                  RefType:
-                    type: string
-                    enum: [RANGE, THOLD, VSET, TEXT, NOREF]
-                  FormulaCode:
-                    type: string
-                    description: Formula expression for CALC type (e.g., "{TBIL} - {DBIL}")
-                  Unit1:
-                    type: string
-                  Factor:
-                    type: number
-                  Unit2:
-                    type: string
-                  Decimal:
-                    type: integer
-                    default: 2
-                  Method:
-                    type: string
-                  ExpectedTAT:
-                    type: integer
-                  members:
-                    type: array
-                    description: |
-                      Array of member tests for CALC and GROUP types.
-                      Each member object must contain `TestSiteID` (the actual test ID).
-                      Do NOT use `Member` or `SeqScr` - these will be rejected with validation error.
-                    items:
-                      type: object
-                      properties:
-                        TestSiteID:
-                          type: integer
-                          description: The actual TestSiteID of the member test (required)
-                      required:
-                        - TestSiteID
+              CountStat:
+                type: integer
+              testdefcal:
+                type: object
+                description: Calculated test metadata persisted in the `testdefcal` table.
+                properties:
+                  FormulaCode:
+                    type: string
+                    description: Formula expression for calculated tests (e.g., "{TBIL} - {DBIL}")
+              testdefgrp:
+                type: object
+                description: Group member payload stored in the `testdefgrp` table.
+                properties:
+                  members:
+                    type: array
+                    description: Array of member TestSiteIDs for CALC/GROUP definitions.
+                    items:
+                      type: object
+                      properties:
+                        TestSiteID:
+                          type: integer
+                          description: Foreign key referencing the member test's TestSiteID.
+                      required:
+                        - TestSiteID
               refnum:
                 type: array
                 items: