diff --git a/.github/workflows/security-scan.yml b/.github/workflows/security-scan.yml
index 28fbc51..b7884e8 100644
--- a/.github/workflows/security-scan.yml
+++ b/.github/workflows/security-scan.yml
@@ -1,154 +1,82 @@
 name: Security Scan
 
 on:
-  pull_request_target:
-    types: [opened, synchronize, reopened]
+  pull_request:
     branches: [main]
 
 permissions:
   contents: read
   pull-requests: write
-  issues: write
-  checks: write
-  security-events: write
-  statuses: write
 
 jobs:
   security-scan:
     runs-on: ubuntu-latest
-    
+
     steps:
-      - name: Checkout PR
+      - name: Checkout PR Code
         uses: actions/checkout@v4
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           fetch-depth: 0
-      
+
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v4
         with:
           python-version: '3.10'
 
-      - name: Cache pip packages
-        uses: actions/cache@v4
-        with:
-          path: ~/.cache/pip
-          key: ${{ runner.os }}-pip-${{ hashFiles('/requirements.txt') }}
-          restore-keys: |
-            ${{ runner.os }}-pip-
-
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install bandit safety
+          pip install bandit pip-audit
+
+      - name: Run Bandit
+        run: |
+          echo "Running Bandit..."
+          bandit -r . -f txt -o bandit-results.txt || true
+
+      - name: Run pip-audit
+        run: |
+          echo "Running pip-audit..."
+          pip-audit -r requirements.txt > pip-audit-results.txt || true
 
-      - name: Run Security Scan
-        id: security_scan
-        env:
-          BANDIT_SKIP_IDS: ${{ secrets.BANDIT_SKIP_IDS }}
+      - name: Combine results
         run: |
-          # Run bandit recursively on all Python files
-          echo "Running Bandit security scan..."
-          
-          bandit -r . \
-          --severity-level medium \
-          --skip "${BANDIT_SKIP_IDS}" \
-          -f txt \
-          -o bandit-results.txt || true
-          
-          # Run Safety check on requirements
-          if [ -f "requirements.txt" ]; then
-            echo "Checking dependencies with Safety..."
-            safety scan -r requirements.txt --output text > safety-results.txt || true
-          fi
-          
-          # Combine results
           echo "🔒 Security Scan Results" > security-scan-results.txt
           echo "=========================" >> security-scan-results.txt
-          echo "" >> security-scan-results.txt
-          
-          if [ -f "bandit-results.txt" ]; then
-            echo "Bandit Scan Results:" >> security-scan-results.txt
-            echo "-------------------" >> security-scan-results.txt
-            cat bandit-results.txt >> security-scan-results.txt
-            echo "" >> security-scan-results.txt
-          fi
-          
-          if [ -f "safety-results.txt" ]; then
-            echo "Dependency Check Results:" >> security-scan-results.txt
-            echo "-----------------------" >> security-scan-results.txt
-            cat safety-results.txt >> security-scan-results.txt
-          fi
-          
-          # Check for critical issues
-          if grep -iE "Severity\:\ High|Severity\:\ Critical" bandit-results.txt > /dev/null 2>&1; then
-            echo "vulnerabilities_found=true" >> $GITHUB_OUTPUT
-          elif [ -f "safety-results.txt" ] && grep -iE "critical" safety-results.txt > /dev/null 2>&1; then
-            echo "vulnerabilities_found=true" >> $GITHUB_OUTPUT
-          else
-            echo "vulnerabilities_found=false" >> $GITHUB_OUTPUT
-          fi
 
-      - name: Create comment body
-        id: create-comment
-        if: always()
-        run: |
-          if [ -f security-scan-results.txt ]; then
-            SCAN_RESULTS=$(cat security-scan-results.txt)
-            if [ "${{ steps.security_scan.outputs.vulnerabilities_found }}" == "true" ]; then
-              echo 'comment_body<<EOF' >> $GITHUB_ENV
-              echo '## 🔒 Security Scan Results' >> $GITHUB_ENV
-              echo '' >> $GITHUB_ENV
-              echo '```' >> $GITHUB_ENV
-              echo "$SCAN_RESULTS" >> $GITHUB_ENV
-              echo '```' >> $GITHUB_ENV
-              echo '' >> $GITHUB_ENV
-              echo '⛔️ **Critical vulnerabilities detected. Please review and address these security issues before merging.**' >> $GITHUB_ENV
-              echo '' >> $GITHUB_ENV
-              echo '### Next Steps:' >> $GITHUB_ENV
-              echo '1. Review each critical finding above and fix them according to OWASP top 10 mitigations.' >> $GITHUB_ENV
-              echo 'EOF' >> $GITHUB_ENV
-            else
-              echo 'comment_body<<EOF' >> $GITHUB_ENV
-              echo '## 🔒 Security Scan Results' >> $GITHUB_ENV
-              echo '' >> $GITHUB_ENV
-              echo '```' >> $GITHUB_ENV
-              echo "$SCAN_RESULTS" >> $GITHUB_ENV
-              echo '```' >> $GITHUB_ENV
-              echo '' >> $GITHUB_ENV
-              echo '✅ **No critical security issues detected.**' >> $GITHUB_ENV
-              echo '' >> $GITHUB_ENV
-              echo 'The code has passed all critical security checks.' >> $GITHUB_ENV
-              echo 'EOF' >> $GITHUB_ENV
-            fi
-          else
-            echo 'comment_body<<EOF' >> $GITHUB_ENV
-            echo '## 🔒 Security Scan Results' >> $GITHUB_ENV
-            echo '' >> $GITHUB_ENV
-            echo '⚠️ **Error: The security scan failed to complete. Please review the workflow logs for more information.**' >> $GITHUB_ENV
-            echo 'EOF' >> $GITHUB_ENV
-          fi
+          echo "" >> security-scan-results.txt
+          echo "📘 Bandit Scan:" >> security-scan-results.txt
+          echo "-------------------" >> security-scan-results.txt
+          cat bandit-results.txt >> security-scan-results.txt
 
-      - name: Comment PR
-        uses: peter-evans/create-or-update-comment@v4
-        if: always()
-        with:
-          issue-number: ${{ github.event.pull_request.number }}
-          body: ${{ env.comment_body }}
+          echo "" >> security-scan-results.txt
+          echo "📦 pip-audit:" >> security-scan-results.txt
+          echo "-------------------" >> security-scan-results.txt
+          cat pip-audit-results.txt >> security-scan-results.txt
 
-      - name: Upload scan artifacts
-        if: always()
+      - name: Upload scan results
         uses: actions/upload-artifact@v4
         with:
           name: security-scan-results
           path: |
             security-scan-results.txt
             bandit-results.txt
-            safety-results.txt
+            pip-audit-results.txt
           retention-days: 5
 
-      - name: Fail if vulnerabilities found
-        if: steps.security_scan.outputs.vulnerabilities_found == 'true'
+      - name: Create PR comment body
+        id: comment_body
         run: |
-          echo "::error::Critical security vulnerabilities were detected. Please review the findings and address them before merging."
-          exit 1
+          echo 'comment<<EOF' >> $GITHUB_ENV
+          echo '## 🔒 Security Scan Summary' >> $GITHUB_ENV
+          echo '' >> $GITHUB_ENV
+          echo '```' >> $GITHUB_ENV
+          cat security-scan-results.txt >> $GITHUB_ENV
+          echo '```' >> $GITHUB_ENV
+          echo 'EOF' >> $GITHUB_ENV
+
+      - name: Post Comment on PR
+        uses: peter-evans/create-or-update-comment@v4
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          body: ${{ env.comment }}
diff --git a/.gitignore b/.gitignore
index 95d4ec6..ac307b1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,4 +3,4 @@ __pycache__/
 env/
 .env
 .ipynb_checkpoints/
-*.db
+logs/app.log
diff --git a/api/sync.py b/api/sync.py
new file mode 100644
index 0000000..966e381
--- /dev/null
+++ b/api/sync.py
@@ -0,0 +1,59 @@
+from datetime import datetime, timezone
+from models.user import UserProfile
+from models import db
+from flask import Blueprint, jsonify, request
+from flask import current_app as app
+
+sync_bp = Blueprint('sync', __name__)
+
+
+@sync_bp.route('/update', methods=['POST'])
+def update_sync_time():
+    try: 
+        user_id = request.json.get('user_id')
+        if not user_id:
+            app.logger.warning(f"[sync/update] missing user_id in payload")
+            return jsonify({'error' : 'Missing user_id'}), 400
+        
+        user = db.session.get(UserProfile, user_id)
+        if not user:
+            app.logger.warning(f"[sync/update] user not found: {user_id}")
+            return jsonify({'error' : 'User not found'}), 404
+        
+        user.last_synced = datetime.now(timezone.utc)
+        db.session.commit()
+        ts = user.last_synced.strftime('%Y-%m-%dT%H:%M:%SZ')
+        app.logger.info(f"[sync/update] updated last_synced for user {user_id}: {ts}")
+        return jsonify({'message' : 'Last sync time updated', 
+                        'user_id' : str(user_id),
+                        'last_synced' : ts
+        }), 200
+    except Exception as e:
+        app.logger.error(f"[sync/update] error for user {user_id}: {e}", exc_info=True)
+        return jsonify({'error': 'Internal server error'}), 500
+
+
+
+@sync_bp.route('/last', methods=['GET'])
+def get_last_sync_time():
+    try: 
+        user_id = request.args.get('user_id')
+        if not user_id:
+            app.logger.warning(f"[sync/last] missing user_id in query")
+            return jsonify({'error': 'Missing user_id'}), 400
+        
+        user = db.session.get(UserProfile, user_id)
+        if not user:
+            app.logger.warning(f"[sync/last] user not found: {user_id}")
+            return jsonify({'error' : 'User not found'}), 404
+        ts = user.last_synced.strftime('%Y-%m-%dT%H:%M:%SZ') if user.last_synced else None
+        app.logger.info(f"[sync/last] fetched last_synced for user {user_id}: {ts}")
+        return jsonify({
+            'user_id' : str(user.id),
+            'last_synced' : ts
+        }), 200
+    except Exception as e:
+        app.logger.error(f"Error fetching sync status: {str(e)}")
+        return jsonify({'error': 'Internal server error'}), 500
+
+
diff --git a/app.py b/app.py
index ddacb32..3b2b2ee 100644
--- a/app.py
+++ b/app.py
@@ -1,4 +1,5 @@
 from flask import Flask, jsonify, session, render_template, request, redirect
+from flask_migrate import Migrate
 from flask_cors import CORS
 from api.routes import api
 from api.goals import goals_bp
@@ -8,18 +9,38 @@
 from api.activity import activity_bp
 from models import db
 from dotenv import load_dotenv
+from api.sync import sync_bp
+from logging.handlers import RotatingFileHandler
+import logging
 import os
 import pyrebase
 
 # Import scripts here 
 from scripts.add_default_user import add_default_user
 
+# ensure a folder for logs exists
+os.makedirs('logs', exist_ok=True)
+
 # Load environment variables from .env file
 load_dotenv()
 
 app = Flask(__name__)
 CORS(app, resources={r"/api/*": {"origins": "http://localhost:5173"}})
 
+
+# set up a rotating file handler
+file_handler = RotatingFileHandler(
+    'logs/app.log', maxBytes=10*1024, backupCount=5
+)
+file_handler.setFormatter(logging.Formatter(
+    '%(asctime)s %(levelname)s in %(module)s: %(message)s'
+))
+file_handler.setLevel(logging.INFO)
+
+app.logger.addHandler(file_handler)
+app.logger.setLevel(logging.INFO)
+app.logger.info("🟢 App startup complete")
+
 # Firebase configuration
 config = {
     'apiKey': os.getenv('FIREBASE_API_KEY'),
@@ -42,6 +63,8 @@
 
 # Initialize database
 db.init_app(app)
+migrate = Migrate(app, db)
+
 with app.app_context():
     db.create_all()
 
@@ -53,6 +76,7 @@
 app.register_blueprint(goals_bp, url_prefix='/api/goals')
 app.register_blueprint(dashboard_bp, url_prefix='/api/dashboard')
 app.register_blueprint(profile_api, url_prefix='/api/profile')
+app.register_blueprint(sync_bp, url_prefix='/api/synced')
 app.register_blueprint(body_insight_bp, url_prefix='/api/body_insight')
 app.register_blueprint(activity_bp, url_prefix='/api/activity')
 
diff --git a/conftest.py b/conftest.py
new file mode 100644
index 0000000..f692378
--- /dev/null
+++ b/conftest.py
@@ -0,0 +1,27 @@
+import pytest
+from app import app as flask_app, db
+from models.user import UserProfile
+
+@pytest.fixture
+def app():
+    # tell Flask to use testing config & in‑memory sqlite
+    flask_app.config.update({
+        "TESTING": True,
+        "SQLALCHEMY_DATABASE_URI": "sqlite:///:memory:",
+        "SQLALCHEMY_TRACK_MODIFICATIONS": False,
+    })
+    with flask_app.app_context():
+        db.create_all()
+        yield flask_app
+        db.drop_all()
+
+@pytest.fixture
+def client(app):
+    return app.test_client()
+
+@pytest.fixture
+def sample_user(app):
+    u = UserProfile(name="Test", account="acct1", birthDate="2000-01-01", gender="F")
+    db.session.add(u)
+    db.session.commit()
+    return u
diff --git a/docs/sync-api.md b/docs/sync-api.md
new file mode 100644
index 0000000..75034d3
--- /dev/null
+++ b/docs/sync-api.md
@@ -0,0 +1,84 @@
+# Time Sync API
+
+
+## 1. Overview 
+
+Log user’s last-sync timestamp and allow retrieving.
+
+### Use Cases:
+    - Audit logs: Verify each data timestamp
+    - Session management
+    - Data consistency: Coordinate time-sensitive updates
+
+
+## 2. Getting Started
+
+### Base URL
+
+    Base path: `https://localhost:5000/api/synced`
+
+### Authentication
+
+    All requests requires an `Authentication` header with Bearer token:
+    Authorization: Bearer `API-TOKEN`
+
+## 3. Endpoints
+### GET
+    Purpose: To fetch data/time based on the recoreded timestamp.
+
+### URL & Method:
+    GET /sync/last
+
+### Parameter
+    - userId: int
+
+### Success Response (200 OK)
+    {
+        "userId": ???,
+        "lastSyncedAt": "????-??-??T??:??:??Z"
+    }
+
+### Error Response
+    - 401 Unauthorized
+        {"error": "Invalid or missing token"}
+    - 404 Not Found
+        {"error": "No sync record found for userId=??"}
+    - 500 Internal Server Error
+        {"error": "Database unavailable"}
+
+### POST
+    Purpose: To record new sync timestamp of a device.
+
+### URL & Method:
+    POST /sync/update
+
+### Parameter
+    - userID: int
+    - syncedAt: string
+
+### Success Response (201 Created)
+    {
+        "userId": ???,
+        "lastSyncedAt": "????-??-??T??:??:??Z"
+    }
+
+### Error Response
+    - 400 Bad Request
+        {"error": "Malformed JSON or missing fields"}
+    - 401 Unauthorized
+        {"error": "Invalid or missing token"}
+    - 500 Internal Server Error
+        {"error": "Failed to write to database"}
+
+## 4. Data Models
+    - userId: int
+    - lastSyncedAt: string
+
+## 5. Error Handling
+    - Always check the HTTP status code first.
+    - Inspect error field in response JSON for details.
+    - Common remedies:
+        401 → Refresh or correct your token
+        400 → Validate your payload structure and fields
+        404 → Ensure userId exists or call POST first
+        500 → Retry after a brief pause; contact support if persistent
\ No newline at end of file
diff --git a/instance/goals_backup.db b/instance/goals_backup.db
new file mode 100644
index 0000000..bad4a7a
Binary files /dev/null and b/instance/goals_backup.db differ
diff --git a/migrations/README b/migrations/README
new file mode 100644
index 0000000..0e04844
--- /dev/null
+++ b/migrations/README
@@ -0,0 +1 @@
+Single-database configuration for Flask.
diff --git a/migrations/alembic.ini b/migrations/alembic.ini
new file mode 100644
index 0000000..ec9d45c
--- /dev/null
+++ b/migrations/alembic.ini
@@ -0,0 +1,50 @@
+# A generic, single database configuration.
+
+[alembic]
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic,flask_migrate
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[logger_flask_migrate]
+level = INFO
+handlers =
+qualname = flask_migrate
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S
diff --git a/migrations/env.py b/migrations/env.py
new file mode 100644
index 0000000..4c97092
--- /dev/null
+++ b/migrations/env.py
@@ -0,0 +1,113 @@
+import logging
+from logging.config import fileConfig
+
+from flask import current_app
+
+from alembic import context
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+fileConfig(config.config_file_name)
+logger = logging.getLogger('alembic.env')
+
+
+def get_engine():
+    try:
+        # this works with Flask-SQLAlchemy<3 and Alchemical
+        return current_app.extensions['migrate'].db.get_engine()
+    except (TypeError, AttributeError):
+        # this works with Flask-SQLAlchemy>=3
+        return current_app.extensions['migrate'].db.engine
+
+
+def get_engine_url():
+    try:
+        return get_engine().url.render_as_string(hide_password=False).replace(
+            '%', '%%')
+    except AttributeError:
+        return str(get_engine().url).replace('%', '%%')
+
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+config.set_main_option('sqlalchemy.url', get_engine_url())
+target_db = current_app.extensions['migrate'].db
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def get_metadata():
+    if hasattr(target_db, 'metadatas'):
+        return target_db.metadatas[None]
+    return target_db.metadata
+
+
+def run_migrations_offline():
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url, target_metadata=get_metadata(), literal_binds=True
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online():
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+
+    # this callback is used to prevent an auto-migration from being generated
+    # when there are no changes to the schema
+    # reference: http://alembic.zzzcomputing.com/en/latest/cookbook.html
+    def process_revision_directives(context, revision, directives):
+        if getattr(config.cmd_opts, 'autogenerate', False):
+            script = directives[0]
+            if script.upgrade_ops.is_empty():
+                directives[:] = []
+                logger.info('No changes in schema detected.')
+
+    conf_args = current_app.extensions['migrate'].configure_args
+    if conf_args.get("process_revision_directives") is None:
+        conf_args["process_revision_directives"] = process_revision_directives
+
+    connectable = get_engine()
+
+    with connectable.connect() as connection:
+        context.configure(
+            connection=connection,
+            target_metadata=get_metadata(),
+            **conf_args
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()
diff --git a/migrations/script.py.mako b/migrations/script.py.mako
new file mode 100644
index 0000000..2c01563
--- /dev/null
+++ b/migrations/script.py.mako
@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}
diff --git a/models/user.py b/models/user.py
index 78f4e21..196fd85 100644
--- a/models/user.py
+++ b/models/user.py
@@ -1,4 +1,5 @@
 from models import db
+from datetime import datetime, timezone
 
 class UserProfile(db.Model):
     __tablename__ = 'user_profile'
diff --git a/tests/sync_test.py b/tests/sync_test.py
new file mode 100644
index 0000000..7008204
--- /dev/null
+++ b/tests/sync_test.py
@@ -0,0 +1,45 @@
+import json
+from datetime import datetime
+import pytest
+
+API = "/api/synced"  
+
+def test_update_missing_id(client):
+    resp = client.post(f"{API}/update", json={})
+    assert resp.status_code == 400
+    assert "Missing user_id" in resp.get_data(as_text=True)
+
+def test_update_not_found(client):
+    resp = client.post(f"{API}/update", json={"user_id": 999})
+    assert resp.status_code == 404
+    assert "User not found" in resp.get_data(as_text=True)
+
+def test_update_success(client, sample_user):
+    resp = client.post(f"{API}/update", json={"user_id": sample_user.id})
+    data = resp.get_json()
+    assert resp.status_code == 200
+    assert data["user_id"] == str(sample_user.id)
+
+    dt = datetime.strptime(data["last_synced"], "%Y-%m-%dT%H:%M:%SZ")
+    assert abs((dt - datetime.utcnow()).total_seconds()) < 5
+
+def test_last_missing_id(client):
+    resp = client.get(f"{API}/last")
+    assert resp.status_code == 400
+    assert "Missing user_id" in resp.get_data(as_text=True)
+
+def test_last_not_found(client):
+    resp = client.get(f"{API}/last?user_id=999")
+    assert resp.status_code == 404
+    assert "User not found" in resp.get_data(as_text=True)
+
+def test_last_success(client, sample_user):
+    # first set a sync
+    client.post(f"{API}/update", json={"user_id": sample_user.id})
+    # then retrieve
+    resp = client.get(f"{API}/last?user_id={sample_user.id}")
+    data = resp.get_json()
+    assert resp.status_code == 200
+    # the last_synced we get back matches the DB
+    assert data["user_id"] == str(sample_user.id)
+    assert "last_synced" in data