diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
new file mode 100644
index 00000000..22ce281b
--- /dev/null
+++ b/.github/workflows/run-tests.yml
@@ -0,0 +1,31 @@
+name: Run Tests
+
+on:
+  pull_request:
+    branches: [ main, master, feature/*]
+  push:
+    branches: [ main, master ]
+
+jobs:
+  test-backend:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
+        
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        cd backend
+        pip install -r requirements.txt
+        
+    - name: Run tests
+      run: |
+        cd $GITHUB_WORKSPACE
+        export PYTHONPATH=$PYTHONPATH:./backend
+        pytest backend/tests/
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index 50e6309d..552a3680 100644
--- a/.gitignore
+++ b/.gitignore
@@ -72,6 +72,7 @@ service-account*.json
 # IDE
 .vscode/settings.json
 .idea/
+.vscode/
 
 # Logs
 *.log
diff --git a/backend/pytest.ini b/backend/pytest.ini
new file mode 100644
index 00000000..606976f3
--- /dev/null
+++ b/backend/pytest.ini
@@ -0,0 +1,13 @@
+[pytest]
+env =
+    SECRET_KEY=test_secret_key_for_pytest_1234567890abcdef
+    TESTING=True # Example: if the app ever needs to know it's in test mode
+
+asyncio_mode = auto
+
+python_files = test_*.py tests_*.py *_test.py *_tests.py
+python_classes = Test* Tests*
+python_functions = test_*
+
+# Optional: Add default command line options if desired
+# addopts = --verbose
diff --git a/backend/requirements.txt b/backend/requirements.txt
index 31e9a808..d969e6dc 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -11,3 +11,8 @@ firebase-admin==6.9.0
 python-dotenv==1.0.0
 bcrypt==4.0.1
 email-validator==2.2.0
+pytest
+pytest-asyncio
+httpx
+mongomock-motor
+pytest-env
diff --git a/backend/tests/auth/test_auth_routes.py b/backend/tests/auth/test_auth_routes.py
new file mode 100644
index 00000000..a2f47b30
--- /dev/null
+++ b/backend/tests/auth/test_auth_routes.py
@@ -0,0 +1,240 @@
+import pytest
+from httpx import AsyncClient, ASGITransport
+from fastapi import FastAPI, status
+from main import app # Assuming your FastAPI app instance is here
+from app.config import settings # To potentially override settings if needed, or check values
+from app.auth.security import verify_password, get_password_hash # For checking hashed password if necessary
+from datetime import datetime
+from bson import ObjectId
+
+# It's good practice to set a specific test secret key if not relying on external env vars
+# For now, we assume 'your-super-secret-jwt-key-change-this-in-production' from config.py is used,
+# or an environment variable overrides it.
+# Ensure settings.secret_key is sufficiently long/random for HS256, the default is.
+
+# Helper to get the mock_db if direct interaction is needed (though often not preferred)
+# from app.database import get_database
+
+@pytest.mark.asyncio
+async def test_signup_with_email_success(mock_db): # mock_db fixture is auto-used
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as ac:
+        signup_data = {
+            "email": "testuser@example.com",
+            "password": "securepassword123",
+            "name": "Test User"
+        }
+        response = await ac.post("/auth/signup/email", json=signup_data)
+    print(f"Response text for test_signup_with_email_success: {response.text}") # Print response text
+    assert response.status_code == status.HTTP_200_OK # Or the actual success code used by the app
+    response_data = response.json()
+    assert "access_token" in response_data
+    assert "refresh_token" in response_data
+    assert "user" in response_data
+    assert response_data["user"]["email"] == signup_data["email"]
+    assert response_data["user"]["name"] == signup_data["name"]
+    assert "_id" in response_data["user"] # Changed 'id' to '_id'
+
+    # Verify user creation in the mock database
+    # db = get_database() # This will be the mock_db instance due to the fixture
+    # Directly using mock_db fixture passed to test function
+    created_user = await mock_db.users.find_one({"email": signup_data["email"]})
+    assert created_user is not None
+    assert created_user["name"] == signup_data["name"]
+    assert verify_password(signup_data["password"], created_user["hashed_password"])
+
+    # Verify refresh token creation
+    refresh_token_record = await mock_db.refresh_tokens.find_one({"user_id": created_user["_id"]})
+    assert refresh_token_record is not None
+    assert not refresh_token_record["revoked"]
+    assert response_data["refresh_token"] == refresh_token_record["token"]
+
+@pytest.mark.asyncio
+async def test_signup_with_existing_email(mock_db):
+    # Pre-populate with a user
+    existing_email = "existing@example.com"
+    await mock_db.users.insert_one({
+        "email": existing_email,
+        "hashed_password": "hashedpassword",
+        "name": "Existing User",
+        "created_at": "sometime" # Simplified for mock
+    })
+
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as ac:
+        signup_data = {
+            "email": existing_email,
+            "password": "newpassword123",
+            "name": "New User"
+        }
+        response = await ac.post("/auth/signup/email", json=signup_data)
+
+    assert response.status_code == status.HTTP_400_BAD_REQUEST
+    response_data = response.json()
+    assert "detail" in response_data
+    assert "User with this email already exists" in response_data["detail"]
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "payload_modifier, affected_field, description",
+    [
+        (lambda p: p.pop("email"), "email", "missing_email"),
+        (lambda p: p.pop("password"), "password", "missing_password"),
+        (lambda p: p.pop("name"), "name", "missing_name"),
+        (lambda p: p.update({"password": "short"}), "password", "short_password"),
+        (lambda p: p.update({"email": "invalidemail"}), "email", "invalid_email"),
+    ]
+)
+async def test_signup_invalid_input_refined(mock_db, payload_modifier, affected_field, description):
+    base_payload = {
+        "email": "testuser@example.com",
+        "password": "securepassword123",
+        "name": "Test User"
+    }
+    payload_modifier(base_payload) # Modify the payload based on the current test case
+
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as ac:
+        response = await ac.post("/auth/signup/email", json=base_payload)
+
+    assert response.status_code == status.HTTP_422_UNPROCESSABLE_ENTITY
+    response_data = response.json()
+    assert "detail" in response_data
+
+    error_found = False
+    for error_item in response_data["detail"]:
+        # Check if the 'loc' array (location of the error) contains the affected_field
+        if affected_field in error_item.get("loc", []):
+            error_type = error_item.get("type", "")
+            # Specific checks for error types for Pydantic v2
+            if description == "short_password" and error_type == "string_too_short":
+                error_found = True
+                break
+            elif description == "invalid_email" and error_type == "value_error": # Simpler check, msg gives more detail
+                error_found = True
+                break
+            elif "missing" in description and error_type == "missing":
+                error_found = True
+                break
+    assert error_found, f"Validation error for '{description}' (field: {affected_field}) not found or not specific enough in {response_data['detail']}"
+
+
+@pytest.mark.asyncio
+async def test_login_with_email_success(mock_db):
+    user_email = "loginuser@example.com"
+    user_password = "loginpassword123"
+    hashed_password = get_password_hash(user_password)
+
+    # Pre-populate user in mock_db
+    # Ensure _id is an ObjectId if other parts of the code expect it,
+    # though for mock_db string usually works fine unless there's specific BSON type checking.
+    # For consistency with how AuthService creates user_id for refresh tokens (ObjectId(user_id)),
+    # let's store _id as ObjectId here.
+    user_obj_id = ObjectId()
+    await mock_db.users.insert_one({
+        "_id": user_obj_id,
+        "email": user_email,
+        "hashed_password": hashed_password,
+        "name": "Login User",
+        "avatar": None,
+        "currency": "USD",
+        "created_at": datetime.utcnow(), # Ensure datetime is used
+        "auth_provider": "email",
+        "firebase_uid": None
+    })
+
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as ac:
+        login_data = {
+            "email": user_email,
+            "password": user_password
+        }
+        response = await ac.post("/auth/login/email", json=login_data)
+
+    assert response.status_code == status.HTTP_200_OK
+    response_data = response.json()
+    assert "access_token" in response_data
+    assert "refresh_token" in response_data
+    assert "user" in response_data
+    assert response_data["user"]["email"] == user_email
+    assert response_data["user"]["_id"] == str(user_obj_id) # Changed 'id' to '_id'
+
+    # Verify refresh token creation for this user
+    # Refresh token service stores user_id as ObjectId
+    refresh_token_record = await mock_db.refresh_tokens.find_one({"user_id": user_obj_id})
+    assert refresh_token_record is not None
+    assert not refresh_token_record["revoked"]
+    assert response_data["refresh_token"] == refresh_token_record["token"]
+
+@pytest.mark.asyncio
+async def test_login_with_incorrect_password(mock_db):
+    user_email = "wrongpass@example.com"
+    correct_password = "correctpassword"
+    incorrect_password = "incorrectpassword"
+
+    await mock_db.users.insert_one({
+        "_id": ObjectId(),
+        "email": user_email,
+        "hashed_password": get_password_hash(correct_password),
+        "name": "Wrong Pass User",
+        "created_at": datetime.utcnow()
+    })
+
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as ac:
+        login_data = {
+            "email": user_email,
+            "password": incorrect_password
+        }
+        response = await ac.post("/auth/login/email", json=login_data)
+
+    assert response.status_code == status.HTTP_401_UNAUTHORIZED
+    response_data = response.json()
+    assert "detail" in response_data
+    assert "Incorrect email or password" in response_data["detail"]
+
+@pytest.mark.asyncio
+async def test_login_with_non_existent_email(mock_db):
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as ac:
+        login_data = {
+            "email": "nosuchuser@example.com",
+            "password": "anypassword"
+        }
+        response = await ac.post("/auth/login/email", json=login_data)
+
+    assert response.status_code == status.HTTP_401_UNAUTHORIZED
+    response_data = response.json()
+    assert "detail" in response_data
+    assert "Incorrect email or password" in response_data["detail"] # Same message for both cases
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "payload_modifier, affected_field, description",
+    [
+        (lambda p: p.pop("email"), "email", "missing_email"),
+        (lambda p: p.pop("password"), "password", "missing_password"),
+        (lambda p: p.update({"email": "invalidemailformat"}), "email", "invalid_email_format"),
+    ]
+)
+async def test_login_invalid_input(mock_db, payload_modifier, affected_field, description):
+    base_payload = {
+        "email": "validuser@example.com",
+        "password": "validpassword123"
+    }
+    # It doesn't matter if the user exists or not for input validation,
+    # as validation happens before DB lookup for these kinds of errors.
+    payload_modifier(base_payload)
+
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as ac:
+        response = await ac.post("/auth/login/email", json=base_payload)
+
+    assert response.status_code == status.HTTP_422_UNPROCESSABLE_ENTITY
+    response_data = response.json()
+    assert "detail" in response_data
+
+    error_found = False
+    for error_item in response_data["detail"]:
+        if affected_field in error_item.get("loc", []):
+            error_type = error_item.get("type", "")
+            if description == "invalid_email_format" and error_type == "value_error": # Simpler check
+                error_found = True
+                break
+            elif "missing" in description and error_type == "missing":
+                error_found = True
+                break
+    assert error_found, f"Validation error for '{description}' (field: {affected_field}) not found in {response_data['detail']}"
diff --git a/backend/tests/conftest.py b/backend/tests/conftest.py
new file mode 100644
index 00000000..7d369a85
--- /dev/null
+++ b/backend/tests/conftest.py
@@ -0,0 +1,75 @@
+import pytest
+import pytest_asyncio
+from unittest.mock import patch, MagicMock
+import firebase_admin # Added
+import os # Added
+from mongomock_motor import AsyncMongoMockClient
+
+@pytest.fixture(scope="session", autouse=True)
+def mock_firebase_admin(request):
+    # Check if we're in a test session that might use firebase,
+    # otherwise this mock might be too broad.
+    # For now, apply session-wide for simplicity as auth_service imports firebase_admin.
+
+    # Mock firebase_admin.credentials.Certificate
+    # Create a mock object that can be called and returns another mock
+    mock_certificate = MagicMock()
+    # When firebase_admin.credentials.Certificate(path) is called, it returns a dummy object
+    mock_certificate.return_value = MagicMock()
+
+    # Mock firebase_admin.initialize_app
+    mock_initialize_app = MagicMock()
+
+    # Mock firebase_admin.auth for verify_id_token if Google login tests were being added
+    mock_firebase_auth = MagicMock()
+    mock_firebase_auth.verify_id_token.return_value = {
+        "uid": "test_firebase_uid",
+        "email": "firebaseuser@example.com",
+        "name": "Firebase User",
+        "picture": None
+    } # Dummy decoded token
+
+    patches = [
+        patch("firebase_admin.credentials.Certificate", mock_certificate),
+        patch("firebase_admin.initialize_app", mock_initialize_app),
+        patch("firebase_admin.auth", mock_firebase_auth) # Mock auth module
+    ]
+
+    for p in patches:
+        p.start()
+        request.addfinalizer(p.stop)
+
+    # Also, to prevent the "Firebase service account not found" print,
+    # we can temporarily set one of the expected firebase env vars
+    # so the code thinks it's configured, but initialize_app being mocked means nothing happens.
+    # This is optional and depends on whether the print is problematic.
+    # with patch.dict(os.environ, {"FIREBASE_PROJECT_ID": "test-project"}, clear=True):
+    # yield
+
+    # If not using the os.environ patch, just yield:
+    yield
+
+@pytest_asyncio.fixture(scope="function", autouse=True)
+async def mock_db():
+    print("mock_db fixture: Creating AsyncMongoMockClient")
+    mock_mongo_client = AsyncMongoMockClient()
+    print(f"mock_db fixture: mock_mongo_client type: {type(mock_mongo_client)}")
+    mock_database_instance = mock_mongo_client["test_db"]
+    print(f"mock_db fixture: mock_database_instance type: {type(mock_database_instance)}, is None: {mock_database_instance is None}")
+
+    # Ensure we are patching the correct target
+    # 'app.database.get_database' is where the function is defined.
+    # 'app.auth.service.get_database' is where it's imported and looked up by AuthService.
+    # Patching where it's looked up can be more robust.
+
+    with patch("app.auth.service.get_database", return_value=mock_database_instance) as mock_get_database_function:
+        print(f"mock_db fixture: Patching app.auth.service.get_database. Patched object: {mock_get_database_function}")
+        print(f"mock_db fixture: Patched return_value: {mock_get_database_function.return_value}, type: {type(mock_get_database_function.return_value)}")
+        yield mock_database_instance # yield the same instance for direct use if needed
+        print("mock_db fixture: Restoring app.auth.service.get_database")
+
+    # Optional: clear all collections in the mock_database after each test
+    # This ensures test isolation.
+    # mongomock doesn't have a straightforward way to list all collections like a real DB,
+    # so we might need to clear known collections if necessary, or rely on new client per test.
+    # For now, a new AsyncMongoMockClient per function scope should provide good isolation.