diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 00000000..d43c223f
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,36 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install dependencies
+        run: pip install -r requirements.txt
+
+      - name: Run tests
+        run: pytest -v
+
+      - name: Build package
+        run: python -m build
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: python-package
+          path: dist/
+
diff --git a/.github/workflows/pr-review.yml b/.github/workflows/pr-review.yml
new file mode 100644
index 00000000..d8838ab8
--- /dev/null
+++ b/.github/workflows/pr-review.yml
@@ -0,0 +1,101 @@
+name: AI Code Review
+
+on:
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  review:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install dependencies
+        run: pip install -r requirements.txt
+
+      - name: Get PR diff
+        run: |
+          git diff origin/main...HEAD > pr_diff.txt
+
+      - name: Run AI review
+        id: ai-review
+        env:
+          GEMINI_API_KEY: ${{ secrets.GEMINI_API_KEY }}
+        run: |
+          REVIEW=$(python scripts/ai_review.py pr_diff.txt)
+          echo "review<<EOF" >> $GITHUB_OUTPUT
+          echo "$REVIEW" >> $GITHUB_OUTPUT
+          echo "EOF" >> $GITHUB_OUTPUT
+          echo "severity=$(cat severity.txt)" >> $GITHUB_OUTPUT
+
+
+      - name: Post review comment
+        uses: actions/github-script@v7
+        env:
+          REVIEW: ${{ steps.ai-review.outputs.review }}
+        with:
+          script: |
+            const review = process.env.REVIEW;
+
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body: `## 🤖 AI Code Review\n\n${review}\n\n---\n*Powered by Gemini AI*`
+            });
+
+      
+      - name: Apply severity label
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const severity = '${{ steps.ai-review.outputs.severity }}';
+
+            const labelMap = {
+              'CRITICAL': 'ai-review: critical',
+              'WARNING': 'ai-review: warning',
+              'GOOD': 'ai-review: looks-good'
+            };
+
+            const label = labelMap[severity] || labelMap['WARNING'];
+
+            // Remove any existing ai-review labels
+            const currentLabels = await github.rest.issues.listLabelsOnIssue({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number
+            });
+
+            for (const existingLabel of currentLabels.data) {
+              if (existingLabel.name.startsWith('ai-review:')) {
+                await github.rest.issues.removeLabel({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: context.issue.number,
+                  name: existingLabel.name
+                });
+              }
+            }
+
+            // Add the new severity label
+            await github.rest.issues.addLabels({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              labels: [label]
+            });
+
+            console.log(`Applied label: ${label}`);
diff --git a/app.py b/app.py
index 8f2f7ae1..6fffa848 100644
--- a/app.py
+++ b/app.py
@@ -14,3 +14,7 @@ def is_even(n: int) -> bool:
 def reverse_string(s: str) -> str:
     """Reverse a string."""
     return s[::-1]
+
+def multiply(a: int, b: int) -> int:
+    """Multiply two numbers together."""
+    return a * b
diff --git a/dangerous.py b/dangerous.py
new file mode 100644
index 00000000..bac1cd37
--- /dev/null
+++ b/dangerous.py
@@ -0,0 +1,8 @@
+import subprocess
+
+def run_command(user_input):
+    subprocess.call(user_input, shell=True)
+
+# Exposed API Key
+API_KEY = "sk-live-abc123def45678"
+
diff --git a/dangerous2.py b/dangerous2.py
new file mode 100644
index 00000000..5853ae91
--- /dev/null
+++ b/dangerous2.py
@@ -0,0 +1,7 @@
+import subprocess
+
+def run_command(user_input):
+    subprocess.call(user_input, shell=True)
+
+# Exposed API Key
+API_KEY = "sk-live-abc123def45678"
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
index 5f456517..80eb1728 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,8 @@
-# Production dependencies (none for this simple app)
+# Production dependencies
+google-genai>=1.0.0
 
 # Development/testing dependencies
 pytest>=7.0.0
 build>=1.0.0
+
+
diff --git a/scripts/ai_review.py b/scripts/ai_review.py
new file mode 100644
index 00000000..9e2c227e
--- /dev/null
+++ b/scripts/ai_review.py
@@ -0,0 +1,85 @@
+from google import genai
+import sys
+
+client = genai.Client()
+
+# Define a function that takes a code diff as input
+def gemini_code_review(diff:str):
+
+    # Write a multi-line f-string prompt that includes {diff_text}
+    # Tell Gemini to act as a code reviewer and focus on security, bugs, performance
+    prompt = f"""You are an expert code reviewer. Review the following code diff and provide feedback.
+
+    Focus on:
+    1. Security vulnerabilities
+    2. Bug risks
+    3. Performance issues
+    4. Best practice violations
+
+    For each issue found, provide:
+    - Severity: HIGH / MEDIUM / LOW
+    - Description of the issue
+    - Suggested fix
+
+    If the code looks good, say so.
+
+    IMPORTANT: At the very end of your review, add a severity summary line in exactly this format:
+    SEVERITY_SUMMARY: <level>
+    Where <level> is one of: CRITICAL, WARNING, GOOD
+
+    Use CRITICAL if any HIGH severity issues exist.
+    Use WARNING if only MEDIUM or LOW severity issues exist.
+    Use GOOD if no issues found.
+
+    Code diff to review:
+
+    {diff_text}
+
+
+    Provide your review in a clear, structured format, ending with the SEVERITY_SUMMARY line."""
+
+
+    # Send the prompt to the model and get a response
+    response = client.models.generate_content(
+        model="gemini-3-flash-preview", contents=prompt
+    )
+
+    # Return just the text from the response
+    return response.text
+
+def parse_severity(review_text):
+    """Extract severity level from the review output."""
+    for line in review_text.strip().split("\n"):
+        if line.strip().startswith("SEVERITY_SUMMARY:"):
+            level = line.split(":", 1)[1].strip().upper()
+            if level in ("CRITICAL", "WARNING", "GOOD"):
+                return level
+    return "WARNING"  # Default to WARNING if parsing fails
+
+
+
+# Only run this code when the script is executed directly
+if __name__ == "__main__":
+
+    # Check if a filename was passed as a command-line argument
+    if len(sys.argv) > 1:
+
+        # Get the filename from sys.argv and read the file
+        diff_file = sys.argv[1]
+        with open(diff_file, "r") as f:
+            diff_content = f.read()
+
+    # If no filename was passed, read from standard input
+    else:
+        diff_content = sys.stdin.read()
+
+    # Call the review function and print the result
+    review = gemini_code_review(diff_content)
+    severity = parse_severity(review)
+
+    print(review)
+    # Open severity.txt for writing
+    with open("severity.txt", "w") as f:
+        # Write the severity string to the file
+        f.write(severity)
+
diff --git a/scripts/sample_diff.txt b/scripts/sample_diff.txt
new file mode 100644
index 00000000..d4b5984b
--- /dev/null
+++ b/scripts/sample_diff.txt
@@ -0,0 +1,17 @@
+diff --git a/app.py b/app.py
+index 1234567..abcdefg 100644
+--- a/app.py
++++ b/app.py
+@@ -1,5 +1,12 @@
+ """Simple utility functions"""
+
++import sqlite3
++
++def get_user(username):
++    conn = sqlite3.connect("users.db")
++    query = f"SELECT * FROM users WHERE name = '{username}'"
++    return conn.execute(query).fetchone()
++
+ def add(a: int, b: int) -> int:
+     """Add two numbers together."""
+     return a + b
diff --git a/tests/test_app.py b/tests/test_app.py
index 79c3e093..034e834a 100644
--- a/tests/test_app.py
+++ b/tests/test_app.py
@@ -1,6 +1,6 @@
 """Tests for app.py - you'll add more!"""
 
-from app import add, is_even, reverse_string
+from app import add, is_even, reverse_string, multiply
 
 
 class TestMath:
@@ -12,6 +12,11 @@ def test_add_positive(self):
     def test_add_negative(self):
         assert add(-1, -1) == -2
 
+    def test_multiply(self):
+        assert multiply(2, 3) == 6
+    
+    
+
 
 class TestStrings:
     """Tests for string functions."""