diff --git a/pyproject.toml b/pyproject.toml
index c4c348f..0a5d0f8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -15,6 +15,12 @@ dependencies = [
     "sqlalchemy[asyncio]>=2.0.44",
 ]
 
+[project.optional-dependencies]
+test = [
+    "pytest>=8.0.0",
+    "pytest-asyncio>=0.25.0",
+]
+
 [project.scripts]
 meta-auth = "meta_api_grabber.auth:main"
 meta-scheduled = "meta_api_grabber.scheduled_grabber:main"
diff --git a/src/meta_api_grabber/scheduled_grabber.py b/src/meta_api_grabber/scheduled_grabber.py
index 557e3f4..de4fcf6 100644
--- a/src/meta_api_grabber/scheduled_grabber.py
+++ b/src/meta_api_grabber/scheduled_grabber.py
@@ -26,6 +26,23 @@ from .view_manager import ViewManager
 logger = logging.getLogger(__name__)
 
 
+common_fields = [
+            AdsInsights.Field.impressions,
+            AdsInsights.Field.clicks,
+            AdsInsights.Field.spend,
+            AdsInsights.Field.cpc,
+            AdsInsights.Field.cpm,
+            AdsInsights.Field.ctr,
+            AdsInsights.Field.cpp,
+            AdsInsights.Field.reach,
+            AdsInsights.Field.frequency,
+            AdsInsights.Field.actions,
+            AdsInsights.Field.cost_per_action_type,
+            AdsInsights.Field.date_start,
+            AdsInsights.Field.date_stop,
+        ]
+
+
 class ScheduledInsightsGrabber:
     """
     Scheduled grabber for Meta ad insights with TimescaleDB storage.
@@ -410,6 +427,120 @@ class ScheduledInsightsGrabber:
 
         print(f"  {count} ad sets cached for {account_id}")
 
+    async def _master_grab_insights(
+        self,
+        account_id: str,
+        fields: list,
+        level: str,
+        db_insert_func,
+        date_preset: Optional[str] = None,
+        start_date: Optional[date] = None,
+        end_date: Optional[date] = None,
+        breakdowns: Optional[list] = None,
+        limit: Optional[int] = None,
+        cache_metadata: bool = False,
+        required_fields: Optional[dict] = None,
+        extra_data_processor=None,
+    ) -> tuple[int, Optional[date]]:
+        """
+        Master method to grab and store insights at any level.
+
+        Args:
+            account_id: Ad account ID
+            fields: List of AdsInsights fields to retrieve
+            level: Insights level ("account", "campaign", "adset", etc.)
+            db_insert_func: Database insert function to call for each insight
+            date_preset: Meta date preset (e.g., "today", "yesterday"). Use either this or start_date/end_date
+            start_date: Start date for custom date range (optional)
+            end_date: End date for custom date range (optional)
+            breakdowns: List of breakdown fields (optional)
+            limit: Maximum number of results (optional)
+            cache_metadata: Whether to cache metadata (for campaign/adset levels)
+            required_fields: Dict of field_name -> label for validation before insert
+            extra_data_processor: Optional callable to process/add extra data to insight_dict
+
+        Returns:
+            Tuple of (count of records stored, date_start from insights)
+        """
+        # Build params
+        params = {"level": level}
+
+        if date_preset:
+            params["date_preset"] = date_preset
+            date_preset_for_db = date_preset
+        else:
+            # Use time_range for custom date ranges
+            params["time_range"] = {
+                "since": start_date.isoformat(),
+                "until": end_date.isoformat(),
+            }
+            params["time_increment"] = 1  # Daily breakdown
+            date_preset_for_db = "custom"
+
+        if breakdowns:
+            params["breakdowns"] = breakdowns
+
+        if limit:
+            params["limit"] = limit
+
+        # Fetch insights from Meta API
+        ad_account = AdAccount(account_id)
+        try:
+            insights = await self._rate_limited_request(
+                ad_account.get_insights,
+                fields=fields,
+                params=params,
+            )
+        except FacebookRequestError as e:
+            error_code = e.api_error_code()
+            if error_code in [190, 102]:  # Invalid OAuth token errors
+                raise ValueError(f"Access token is invalid (error {error_code}): {e.api_error_message()}")
+            raise
+
+        # Get account timezone from database
+        account_timezone = await self._get_account_timezone(account_id)
+
+        # Store insights
+        count = 0
+        date_start_value = None
+
+        for insight in insights:
+            insight_dict = dict(insight)
+
+            # Extract date_start if available (for return value)
+            date_start_str = insight_dict.get("date_start")
+            if date_start_str and date_start_value is None:
+                date_start_value = date.fromisoformat(date_start_str)
+
+            # Check required fields before processing
+            if required_fields:
+                skip = False
+                for field_name, field_label in required_fields.items():
+                    if not insight_dict.get(field_name):
+                        skip = True
+                        break
+                if skip:
+                    continue
+
+            # Call extra processor if provided
+            if extra_data_processor:
+                extra_data_processor(insight_dict)
+
+            # Compute appropriate timestamp based on date_start and account timezone
+            timestamp = self._compute_timestamp(date_start_str, account_timezone)
+
+            # Call the appropriate database insert function
+            await db_insert_func(
+                time=timestamp,
+                account_id=account_id,
+                data=insight_dict,
+                date_preset=date_preset_for_db,
+                cache_metadata=cache_metadata,
+            )
+            count += 1
+
+        return count, date_start_value
+
     async def grab_account_insights(self, account_id: str, date_preset: str = "today") -> Optional[date]:
         """
         Grab and store account-level insights.
@@ -437,50 +568,13 @@ class ScheduledInsightsGrabber:
             AdsInsights.Field.date_stop,
         ]
 
-        params = {
-            "date_preset": date_preset,
-            "level": "account",
-        }
-
-        ad_account = AdAccount(account_id)
-        try:
-            insights = await self._rate_limited_request(
-                ad_account.get_insights,
-                fields=fields,
-                params=params,
-            )
-        except FacebookRequestError as e:
-            # Check if it's a token error
-            error_code = e.api_error_code()
-            if error_code in [190, 102]:  # Invalid OAuth token errors
-                raise ValueError(f"Access token is invalid (error {error_code}): {e.api_error_message()}")
-            raise
-
-        # Get account timezone from database
-        account_timezone = await self._get_account_timezone(account_id)
-
-        # Store insights
-        count = 0
-        date_start_value = None
-
-        for insight in insights:
-            insight_dict = dict(insight)
-
-            # Extract date_start if available
-            date_start_str = insight_dict.get("date_start")
-            if date_start_str and date_start_value is None:
-                date_start_value = date.fromisoformat(date_start_str)
-
-            # Compute appropriate timestamp based on date_start and account timezone
-            timestamp = self._compute_timestamp(date_start_str, account_timezone)
-
-            await self.db.insert_account_insights(
-                time=timestamp,
-                account_id=account_id,
-                data=insight_dict,
-                date_preset=date_preset,
-            )
-            count += 1
+        count, date_start_value = await self._master_grab_insights(
+            account_id=account_id,
+            fields=fields,
+            level="account",
+            db_insert_func=self.db.insert_account_insights,
+            date_preset=date_preset,
+        )
 
         print(f"  Account insights stored for {account_id} ({count} records, date: {date_start_value})")
         return date_start_value
@@ -494,64 +588,23 @@ class ScheduledInsightsGrabber:
             date_preset: Meta date preset
             limit: Maximum number of campaigns
         """
-        fields = [
+
+        fields = common_fields + [
             AdsInsights.Field.campaign_id,
             AdsInsights.Field.campaign_name,
-            AdsInsights.Field.impressions,
-            AdsInsights.Field.clicks,
-            AdsInsights.Field.spend,
-            AdsInsights.Field.ctr,
-            AdsInsights.Field.cpc,
-            AdsInsights.Field.cpm,
-            AdsInsights.Field.reach,
-            AdsInsights.Field.actions,
-            AdsInsights.Field.date_start,
-            AdsInsights.Field.date_stop,
         ]
 
-        params = {
-            "date_preset": date_preset,
-            "level": "campaign",
-            "limit": limit,
-        }
 
-        ad_account = AdAccount(account_id)
-        try:
-            insights = await self._rate_limited_request(
-                ad_account.get_insights,
-                fields=fields,
-                params=params,
-            )
-        except FacebookRequestError as e:
-            error_code = e.api_error_code()
-            if error_code in [190, 102]:
-                raise ValueError(f"Access token is invalid (error {error_code}): {e.api_error_message()}")
-            raise
-
-        # Get account timezone from database
-        account_timezone = await self._get_account_timezone(account_id)
-
-        # Store insights (metadata is automatically cached from insights data)
-        count = 0
-        for insight in insights:
-            campaign_id = insight.get('campaign_id')
-            if campaign_id:
-                insight_dict = dict(insight)
-
-                # Compute appropriate timestamp based on date_preset and account timezone
-                date_start_str = insight_dict.get("date_start")
-                timestamp = self._compute_timestamp(date_start_str, account_timezone)
-
-                # Insert insights - metadata is automatically cached from the insights data
-                await self.db.insert_campaign_insights(
-                    time=timestamp,
-                    campaign_id=campaign_id,
-                    account_id=account_id,
-                    data=insight_dict,
-                    date_preset=date_preset,
-                    cache_metadata=True,  # Automatically cache campaign name from insights
-                )
-                count += 1
+        count, _ = await self._master_grab_insights(
+            account_id=account_id,
+            fields=fields,
+            level="campaign",
+            db_insert_func=self.db.insert_campaign_insights,
+            date_preset=date_preset,
+            limit=limit,
+            cache_metadata=True,
+            required_fields={"campaign_id": "campaign_id"},
+        )
 
         print(f"  Campaign insights stored for {account_id} ({count} records)")
 
@@ -580,51 +633,16 @@ class ScheduledInsightsGrabber:
             AdsInsights.Field.date_stop,
         ]
 
-        params = {
-            "date_preset": date_preset,
-            "level": "adset",
-            "limit": limit,
-        }
-
-        ad_account = AdAccount(account_id)
-        try:
-            insights = await self._rate_limited_request(
-                ad_account.get_insights,
-                fields=fields,
-                params=params,
-            )
-        except FacebookRequestError as e:
-            error_code = e.api_error_code()
-            if error_code in [190, 102]:
-                raise ValueError(f"Access token is invalid (error {error_code}): {e.api_error_message()}")
-            raise
-
-        # Get account timezone from database
-        account_timezone = await self._get_account_timezone(account_id)
-
-        # Store insights (metadata is automatically cached from insights data)
-        count = 0
-        for insight in insights:
-            adset_id = insight.get('adset_id')
-            campaign_id = insight.get('campaign_id')
-            if adset_id and campaign_id:
-                insight_dict = dict(insight)
-
-                # Compute appropriate timestamp based on date_preset and account timezone
-                date_start_str = insight_dict.get("date_start")
-                timestamp = self._compute_timestamp(date_start_str, account_timezone)
-
-                # Insert insights - metadata is automatically cached from the insights data
-                await self.db.insert_adset_insights(
-                    time=timestamp,
-                    adset_id=adset_id,
-                    campaign_id=campaign_id,
-                    account_id=account_id,
-                    data=insight_dict,
-                    date_preset=date_preset,
-                    cache_metadata=True,  # Automatically cache adset/campaign from insights
-                )
-                count += 1
+        count, _ = await self._master_grab_insights(
+            account_id=account_id,
+            fields=fields,
+            level="adset",
+            db_insert_func=self.db.insert_adset_insights,
+            date_preset=date_preset,
+            limit=limit,
+            cache_metadata=True,
+            required_fields={"adset_id": "adset_id", "campaign_id": "campaign_id"},
+        )
 
         print(f"  Ad set insights stored for {account_id} ({count} records)")
 
@@ -637,66 +655,21 @@ class ScheduledInsightsGrabber:
             date_preset: Meta date preset
             limit: Maximum number of campaigns
         """
-        fields = [
+        fields = common_fields + [
             AdsInsights.Field.campaign_id,
             AdsInsights.Field.campaign_name,
-            AdsInsights.Field.impressions,
-            AdsInsights.Field.clicks,
-            AdsInsights.Field.spend,
-            AdsInsights.Field.ctr,
-            AdsInsights.Field.cpc,
-            AdsInsights.Field.cpm,
-            AdsInsights.Field.reach,
-            AdsInsights.Field.actions,
-            AdsInsights.Field.date_start,
-            AdsInsights.Field.date_stop,
         ]
 
-        params = {
-            "date_preset": date_preset,
-            "level": "campaign",
-            "breakdowns": [AdsInsights.Breakdowns.country],
-            "limit": limit,
-        }
-
-        ad_account = AdAccount(account_id)
-        try:
-            insights = await self._rate_limited_request(
-                ad_account.get_insights,
-                fields=fields,
-                params=params,
-            )
-        except FacebookRequestError as e:
-            error_code = e.api_error_code()
-            if error_code in [190, 102]:
-                raise ValueError(f"Access token is invalid (error {error_code}): {e.api_error_message()}")
-            raise
-
-        # Get account timezone from database
-        account_timezone = await self._get_account_timezone(account_id)
-
-        # Store insights (metadata is automatically cached from insights data)
-        count = 0
-        for insight in insights:
-            campaign_id = insight.get('campaign_id')
-            country = insight.get('country')
-            if campaign_id and country:
-                insight_dict = dict(insight)
-
-                # Compute appropriate timestamp based on date_preset and account timezone
-                date_start_str = insight_dict.get("date_start")
-                timestamp = self._compute_timestamp(date_start_str, account_timezone)
-
-                # Insert insights - metadata is automatically cached from the insights data
-                await self.db.insert_campaign_insights_by_country(
-                    time=timestamp,
-                    campaign_id=campaign_id,
-                    account_id=account_id,
-                    country=country,
-                    data=insight_dict,
-                    date_preset=date_preset,
-                )
-                count += 1
+        count, _ = await self._master_grab_insights(
+            account_id=account_id,
+            fields=fields,
+            level="campaign",
+            db_insert_func=self.db.insert_campaign_insights_by_country,
+            date_preset=date_preset,
+            breakdowns=[AdsInsights.Breakdowns.country],
+            limit=limit,
+            required_fields={"campaign_id": "campaign_id", "country": "country"},
+        )
 
         print(f"  Campaign insights by country stored for {account_id} ({count} records)")
 
@@ -733,48 +706,14 @@ class ScheduledInsightsGrabber:
             AdsInsights.Field.date_stop,
         ]
 
-        # Use time_range instead of date_preset for custom date ranges
-        params = {
-            "time_range": {
-                "since": start_date.isoformat(),
-                "until": end_date.isoformat(),
-            },
-            "level": "account",
-            "time_increment": 1,  # Daily breakdown
-        }
-
-        ad_account = AdAccount(account_id)
-        try:
-            insights = await self._rate_limited_request(
-                ad_account.get_insights,
-                fields=fields,
-                params=params,
-            )
-        except FacebookRequestError as e:
-            error_code = e.api_error_code()
-            if error_code in [190, 102]:
-                raise ValueError(f"Access token is invalid (error {error_code}): {e.api_error_message()}")
-            raise
-
-        # Get account timezone from database
-        account_timezone = await self._get_account_timezone(account_id)
-
-        # Store insights
-        count = 0
-        for insight in insights:
-            insight_dict = dict(insight)
-
-            # Compute appropriate timestamp based on date_start and account timezone
-            date_start_str = insight_dict.get("date_start")
-            timestamp = self._compute_timestamp(date_start_str, account_timezone)
-
-            await self.db.insert_account_insights(
-                time=timestamp,
-                account_id=account_id,
-                data=insight_dict,
-                date_preset="custom",  # Indicate this was a custom date range
-            )
-            count += 1
+        count, _ = await self._master_grab_insights(
+            account_id=account_id,
+            fields=fields,
+            level="account",
+            db_insert_func=self.db.insert_account_insights,
+            start_date=start_date,
+            end_date=end_date,
+        )
 
         return count
 
@@ -812,51 +751,17 @@ class ScheduledInsightsGrabber:
             AdsInsights.Field.date_stop,
         ]
 
-        params = {
-            "time_range": {
-                "since": start_date.isoformat(),
-                "until": end_date.isoformat(),
-            },
-            "level": "campaign",
-            "time_increment": 1,  # Daily breakdown
-            "limit": limit,
-        }
-
-        ad_account = AdAccount(account_id)
-        try:
-            insights = await self._rate_limited_request(
-                ad_account.get_insights,
-                fields=fields,
-                params=params,
-            )
-        except FacebookRequestError as e:
-            error_code = e.api_error_code()
-            if error_code in [190, 102]:
-                raise ValueError(f"Access token is invalid (error {error_code}): {e.api_error_message()}")
-            raise
-
-        # Get account timezone from database
-        account_timezone = await self._get_account_timezone(account_id)
-
-        # Store insights
-        count = 0
-        for insight in insights:
-            campaign_id = insight.get('campaign_id')
-            if campaign_id:
-                insight_dict = dict(insight)
-
-                date_start_str = insight_dict.get("date_start")
-                timestamp = self._compute_timestamp(date_start_str, account_timezone)
-
-                await self.db.insert_campaign_insights(
-                    time=timestamp,
-                    campaign_id=campaign_id,
-                    account_id=account_id,
-                    data=insight_dict,
-                    date_preset="custom",
-                    cache_metadata=True,
-                )
-                count += 1
+        count, _ = await self._master_grab_insights(
+            account_id=account_id,
+            fields=fields,
+            level="campaign",
+            db_insert_func=self.db.insert_campaign_insights,
+            start_date=start_date,
+            end_date=end_date,
+            limit=limit,
+            cache_metadata=True,
+            required_fields={"campaign_id": "campaign_id"},
+        )
 
         return count
 
@@ -895,53 +800,17 @@ class ScheduledInsightsGrabber:
             AdsInsights.Field.date_stop,
         ]
 
-        params = {
-            "time_range": {
-                "since": start_date.isoformat(),
-                "until": end_date.isoformat(),
-            },
-            "level": "adset",
-            "time_increment": 1,  # Daily breakdown
-            "limit": limit,
-        }
-
-        ad_account = AdAccount(account_id)
-        try:
-            insights = await self._rate_limited_request(
-                ad_account.get_insights,
-                fields=fields,
-                params=params,
-            )
-        except FacebookRequestError as e:
-            error_code = e.api_error_code()
-            if error_code in [190, 102]:
-                raise ValueError(f"Access token is invalid (error {error_code}): {e.api_error_message()}")
-            raise
-
-        # Get account timezone from database
-        account_timezone = await self._get_account_timezone(account_id)
-
-        # Store insights
-        count = 0
-        for insight in insights:
-            adset_id = insight.get('adset_id')
-            campaign_id = insight.get('campaign_id')
-            if adset_id and campaign_id:
-                insight_dict = dict(insight)
-
-                date_start_str = insight_dict.get("date_start")
-                timestamp = self._compute_timestamp(date_start_str, account_timezone)
-
-                await self.db.insert_adset_insights(
-                    time=timestamp,
-                    adset_id=adset_id,
-                    campaign_id=campaign_id,
-                    account_id=account_id,
-                    data=insight_dict,
-                    date_preset="custom",
-                    cache_metadata=True,
-                )
-                count += 1
+        count, _ = await self._master_grab_insights(
+            account_id=account_id,
+            fields=fields,
+            level="adset",
+            db_insert_func=self.db.insert_adset_insights,
+            start_date=start_date,
+            end_date=end_date,
+            limit=limit,
+            cache_metadata=True,
+            required_fields={"adset_id": "adset_id", "campaign_id": "campaign_id"},
+        )
 
         return count
 
diff --git a/src/meta_api_grabber/view_manager.py b/src/meta_api_grabber/view_manager.py
index 1aec1dc..6ef3f86 100644
--- a/src/meta_api_grabber/view_manager.py
+++ b/src/meta_api_grabber/view_manager.py
@@ -92,6 +92,7 @@ class ViewManager:
                 "adset_insights_flattened",
                 "account_insights_flattened",
                 "campaign_insights_flattened",
+                "campaign_insights_by_country_flattened",
             ]
 
         async with self.pool.acquire() as conn:
diff --git a/tests/README.md b/tests/README.md
new file mode 100644
index 0000000..7ef383a
--- /dev/null
+++ b/tests/README.md
@@ -0,0 +1,58 @@
+# Tests
+
+This directory contains tests for the meta_api_grabber project.
+
+## Running Tests
+
+Install test dependencies:
+```bash
+uv sync --extra test
+```
+
+Run all tests:
+```bash
+uv run pytest
+```
+
+Run specific test file:
+```bash
+uv run pytest tests/test_field_schema_validation.py -v
+```
+
+Run with coverage:
+```bash
+uv run pytest --cov=meta_api_grabber
+```
+
+## Test Files
+
+### `test_field_schema_validation.py`
+Validates that all fields requested by the grab_* methods in `scheduled_grabber.py` exist in the database schema. This ensures:
+- Field compatibility between Meta API and database
+- Early detection of schema mismatches
+- Consistency across all insight levels (account, campaign, adset, country)
+
+**Why this test is important:** When new fields are added to the Meta API field lists, this test quickly alerts you if the corresponding database columns need to be added.
+
+## Writing Tests
+
+Use markers to categorize tests:
+```python
+@pytest.mark.unit
+def test_something():
+    pass
+
+@pytest.mark.integration
+async def test_database_connection():
+    pass
+```
+
+Run only unit tests:
+```bash
+uv run pytest -m unit
+```
+
+Run everything except integration tests:
+```bash
+uv run pytest -m "not integration"
+```
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..b213d57
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1 @@
+"""Tests for meta_api_grabber package."""
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..f98deef
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,13 @@
+"""Pytest configuration and fixtures."""
+
+import pytest
+
+
+def pytest_configure(config):
+    """Configure pytest."""
+    config.addinivalue_line(
+        "markers", "integration: marks tests as integration tests (deselect with '-m \"not integration\"')"
+    )
+    config.addinivalue_line(
+        "markers", "unit: marks tests as unit tests"
+    )
diff --git a/tests/test_field_schema_validation.py b/tests/test_field_schema_validation.py
new file mode 100644
index 0000000..d13d914
--- /dev/null
+++ b/tests/test_field_schema_validation.py
@@ -0,0 +1,245 @@
+"""
+Test that validates all fields requested by grab_* methods exist in the database schema.
+
+This test ensures that whenever new fields are added to the Meta API field lists,
+the corresponding database columns exist. It catches schema mismatches early.
+"""
+
+import pytest
+from facebook_business.adobjects.adsinsights import AdsInsights
+
+
+# Database schema field mappings
+# Maps API field names to database column names
+FIELD_MAPPINGS = {
+    # Core metrics
+    "impressions": "impressions",
+    "clicks": "clicks",
+    "spend": "spend",
+    "reach": "reach",
+    "frequency": "frequency",
+
+    # Calculated metrics
+    "ctr": "ctr",
+    "cpc": "cpc",
+    "cpm": "cpm",
+    "cpp": "cpp",
+
+    # Actions and costs
+    "actions": "actions",
+    "cost_per_action_type": "cost_per_action_type",
+
+    # Date/time fields
+    "date_start": "date_start",
+    "date_stop": "date_stop",
+
+    # ID fields (not stored in insights tables, but referenced)
+    "campaign_id": "referenced_in_campaigns",
+    "campaign_name": "referenced_in_campaigns",
+    "adset_id": "referenced_in_adsets",
+    "adset_name": "referenced_in_adsets",
+    "country": "country",
+}
+
+# Table schemas
+TABLE_SCHEMAS = {
+    "account_insights": {
+        "impressions", "clicks", "spend", "reach", "frequency",
+        "ctr", "cpc", "cpm", "cpp", "actions", "cost_per_action_type",
+        "date_start", "date_stop", "date_preset", "fetched_at"
+    },
+    "campaign_insights": {
+        "impressions", "clicks", "spend", "reach",
+        "ctr", "cpc", "cpm", "actions",
+        "date_start", "date_stop", "date_preset", "fetched_at",
+        "campaign_id", "account_id"
+    },
+    "adset_insights": {
+        "impressions", "clicks", "spend", "reach",
+        "ctr", "cpc", "cpm", "actions",
+        "date_start", "date_stop", "date_preset", "fetched_at",
+        "adset_id", "campaign_id", "account_id"
+    },
+    "campaign_insights_by_country": {
+        "impressions", "clicks", "spend", "reach",
+        "ctr", "cpc", "cpm", "actions",
+        "date_start", "date_stop", "date_preset", "fetched_at",
+        "campaign_id", "account_id", "country"
+    }
+}
+
+
+def get_field_value(field_obj) -> str:
+    """Extract field name from AdsInsights.Field object."""
+    # AdsInsights.Field attributes are simple string values
+    return str(field_obj)
+
+
+class TestFieldSchemaValidation:
+    """Validate that all API field requests have corresponding database columns."""
+
+    def test_account_insights_fields(self):
+        """Test that account insights fields exist in schema."""
+        fields = [
+            AdsInsights.Field.impressions,
+            AdsInsights.Field.clicks,
+            AdsInsights.Field.spend,
+            AdsInsights.Field.cpc,
+            AdsInsights.Field.cpm,
+            AdsInsights.Field.ctr,
+            AdsInsights.Field.cpp,
+            AdsInsights.Field.reach,
+            AdsInsights.Field.frequency,
+            AdsInsights.Field.actions,
+            AdsInsights.Field.cost_per_action_type,
+            AdsInsights.Field.date_start,
+            AdsInsights.Field.date_stop,
+        ]
+
+        schema_fields = TABLE_SCHEMAS["account_insights"]
+        for field in fields:
+            field_name = get_field_value(field)
+            assert field_name in FIELD_MAPPINGS, f"Field '{field_name}' not in FIELD_MAPPINGS"
+            db_column = FIELD_MAPPINGS[field_name]
+
+            # Skip reference checks for ID fields
+            if "referenced_in" not in db_column:
+                assert db_column in schema_fields, \
+                    f"Account insights field '{field_name}' (DB: '{db_column}') not in schema"
+
+    def test_campaign_insights_fields(self):
+        """Test that campaign insights fields exist in schema."""
+        fields = [
+            AdsInsights.Field.campaign_id,
+            AdsInsights.Field.campaign_name,
+            AdsInsights.Field.impressions,
+            AdsInsights.Field.clicks,
+            AdsInsights.Field.spend,
+            AdsInsights.Field.ctr,
+            AdsInsights.Field.cpc,
+            AdsInsights.Field.cpm,
+            AdsInsights.Field.reach,
+            AdsInsights.Field.actions,
+            AdsInsights.Field.date_start,
+            AdsInsights.Field.date_stop,
+        ]
+
+        schema_fields = TABLE_SCHEMAS["campaign_insights"]
+        for field in fields:
+            field_name = get_field_value(field)
+            assert field_name in FIELD_MAPPINGS, f"Field '{field_name}' not in FIELD_MAPPINGS"
+            db_column = FIELD_MAPPINGS[field_name]
+
+            # Skip reference checks for ID/name fields
+            if "referenced_in" not in db_column:
+                assert db_column in schema_fields, \
+                    f"Campaign insights field '{field_name}' (DB: '{db_column}') not in schema"
+
+    def test_adset_insights_fields(self):
+        """Test that adset insights fields exist in schema."""
+        fields = [
+            AdsInsights.Field.adset_id,
+            AdsInsights.Field.adset_name,
+            AdsInsights.Field.campaign_id,
+            AdsInsights.Field.impressions,
+            AdsInsights.Field.clicks,
+            AdsInsights.Field.spend,
+            AdsInsights.Field.ctr,
+            AdsInsights.Field.cpc,
+            AdsInsights.Field.cpm,
+            AdsInsights.Field.reach,
+            AdsInsights.Field.actions,
+            AdsInsights.Field.date_start,
+            AdsInsights.Field.date_stop,
+        ]
+
+        schema_fields = TABLE_SCHEMAS["adset_insights"]
+        for field in fields:
+            field_name = get_field_value(field)
+            assert field_name in FIELD_MAPPINGS, f"Field '{field_name}' not in FIELD_MAPPINGS"
+            db_column = FIELD_MAPPINGS[field_name]
+
+            # Skip reference checks for ID/name fields
+            if "referenced_in" not in db_column:
+                assert db_column in schema_fields, \
+                    f"Adset insights field '{field_name}' (DB: '{db_column}') not in schema"
+
+    def test_campaign_insights_by_country_fields(self):
+        """Test that campaign insights by country fields exist in schema."""
+        fields = [
+            AdsInsights.Field.campaign_id,
+            AdsInsights.Field.campaign_name,
+            AdsInsights.Field.impressions,
+            AdsInsights.Field.clicks,
+            AdsInsights.Field.spend,
+            AdsInsights.Field.ctr,
+            AdsInsights.Field.cpc,
+            AdsInsights.Field.cpm,
+            AdsInsights.Field.reach,
+            AdsInsights.Field.actions,
+            AdsInsights.Field.date_start,
+            AdsInsights.Field.date_stop,
+        ]
+
+        schema_fields = TABLE_SCHEMAS["campaign_insights_by_country"]
+        for field in fields:
+            field_name = get_field_value(field)
+            assert field_name in FIELD_MAPPINGS, f"Field '{field_name}' not in FIELD_MAPPINGS"
+            db_column = FIELD_MAPPINGS[field_name]
+
+            # Skip reference checks for ID/name fields
+            if "referenced_in" not in db_column:
+                assert db_column in schema_fields, \
+                    f"Campaign by country insights field '{field_name}' (DB: '{db_column}') not in schema"
+
+        # Country breakdown field
+        assert "country" in schema_fields, "Country field missing in campaign_insights_by_country schema"
+
+    def test_common_fields_consistency(self):
+        """Test that common_fields are consistent across all methods."""
+        from meta_api_grabber.scheduled_grabber import common_fields
+
+        # Verify common_fields is defined and contains expected metrics
+        expected_metrics = {
+            "impressions", "clicks", "spend", "cpc", "cpm", "ctr", "cpp",
+            "reach", "frequency", "actions", "cost_per_action_type",
+            "date_start", "date_stop"
+        }
+
+        common_field_names = {get_field_value(f) for f in common_fields}
+
+        for metric in expected_metrics:
+            assert metric in common_field_names, \
+                f"Common metric '{metric}' not found in common_fields"
+
+    def test_all_table_schemas_valid(self):
+        """Test that all table schemas are properly defined."""
+        required_tables = {
+            "account_insights",
+            "campaign_insights",
+            "adset_insights",
+            "campaign_insights_by_country"
+        }
+
+        for table in required_tables:
+            assert table in TABLE_SCHEMAS, f"Table '{table}' not defined in TABLE_SCHEMAS"
+            assert len(TABLE_SCHEMAS[table]) > 0, f"Table '{table}' has no fields defined"
+
+
+class TestSchemaDocumentation:
+    """Document the expected schema structure for reference."""
+
+    def test_schema_documentation(self):
+        """Print out the schema for verification purposes."""
+        print("\n" + "="*80)
+        print("DATABASE SCHEMA DOCUMENTATION")
+        print("="*80)
+
+        for table, fields in TABLE_SCHEMAS.items():
+            print(f"\nTable: {table}")
+            print(f"Columns: {sorted(fields)}")
+            print(f"Total columns: {len(fields)}")
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v"])
diff --git a/uv.lock b/uv.lock
index e919d6a..ec5d39f 100644
--- a/uv.lock
+++ b/uv.lock
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     { url = "https://files.pythonhosted.org/packages/0a/4c/925909008ed5a988ccbb72dcc897407e5d6d3bd72410d69e051fc0c14647/charset_normalizer-3.4.4-py3-none-any.whl", hash = "sha256:7a32c560861a02ff789ad905a2fe94e3f840803362c84fecf1851cb4cf3dc37f", size = 53402, upload-time = "2025-10-14T04:42:31.76Z" },
 ]
 
+[[package]]
+name = "colorama"
+version = "0.4.6"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/d8/53/6f443c9a4a8358a93a6792e2acffb9d9d5cb0a5cfd8802644b7b1c9a02e4/colorama-0.4.6.tar.gz", hash = "sha256:08695f5cb7ed6e0531a20572697297273c47b8cae5a63ffc6d6ed5c201be6e44", size = 27697, upload-time = "2022-10-25T02:36:22.414Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/d1/d6/3965ed04c63042e047cb6a3e6ed1a63a35087b6a609aa3a15ed8ac56c221/colorama-0.4.6-py2.py3-none-any.whl", hash = "sha256:4f1d9991f5acc0ca119f9d443620b77f9d6b33703e51011c16baf57afb285fc6", size = 25335, upload-time = "2022-10-25T02:36:20.889Z" },
+]
+
 [[package]]
 name = "curlify"
 version = "3.0.0"
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+    { url = "https://files.pythonhosted.org/packages/1c/53/f9c440463b3057485b8594d7a638bed53ba531165ef0ca0e6c364b5cc807/greenlet-3.2.4-cp313-cp313-musllinux_1_2_aarch64.whl", hash = "sha256:6e343822feb58ac4d0a1211bd9399de2b3a04963ddeec21530fc426cc121f19b", size = 1564759, upload-time = "2025-11-04T12:42:19.395Z" },
+    { url = "https://files.pythonhosted.org/packages/47/e4/3bb4240abdd0a8d23f4f88adec746a3099f0d86bfedb623f063b2e3b4df0/greenlet-3.2.4-cp313-cp313-musllinux_1_2_x86_64.whl", hash = "sha256:ca7f6f1f2649b89ce02f6f229d7c19f680a6238af656f61e0115b24857917929", size = 1634288, upload-time = "2025-11-04T12:42:21.174Z" },
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+    { url = "https://files.pythonhosted.org/packages/0d/da/343cd760ab2f92bac1845ca07ee3faea9fe52bee65f7bcb19f16ad7de08b/greenlet-3.2.4-cp314-cp314-musllinux_1_2_x86_64.whl", hash = "sha256:015d48959d4add5d6c9f6c5210ee3803a830dce46356e3bc326d6776bde54681", size = 1680760, upload-time = "2025-11-04T12:42:25.341Z" },
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 ]
 
+[[package]]
+name = "iniconfig"
+version = "2.3.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/72/34/14ca021ce8e5dfedc35312d08ba8bf51fdd999c576889fc2c24cb97f4f10/iniconfig-2.3.0.tar.gz", hash = "sha256:c76315c77db068650d49c5b56314774a7804df16fee4402c1f19d6d15d8c4730", size = 20503, upload-time = "2025-10-18T21:55:43.219Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/cb/b1/3846dd7f199d53cb17f49cba7e651e9ce294d8497c8c150530ed11865bb8/iniconfig-2.3.0-py3-none-any.whl", hash = "sha256:f631c04d2c48c52b84d0d0549c99ff3859c98df65b3101406327ecc7d53fbf12", size = 7484, upload-time = "2025-10-18T21:55:41.639Z" },
+]
+
 [[package]]
 name = "mako"
 version = "1.3.10"
@@ -525,6 +547,12 @@ dependencies = [
     { name = "sqlalchemy", extra = ["asyncio"] },
 ]
 
+[package.optional-dependencies]
+test = [
+    { name = "pytest" },
+    { name = "pytest-asyncio" },
+]
+
 [package.metadata]
 requires-dist = [
     { name = "aiohttp", specifier = ">=3.13.1" },
@@ -532,10 +560,13 @@ requires-dist = [
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     { name = "facebook-business", specifier = ">=23.0.3" },
     { name = "google-ads", specifier = ">=28.3.0" },
+    { name = "pytest", marker = "extra == 'test'", specifier = ">=8.0.0" },
+    { name = "pytest-asyncio", marker = "extra == 'test'", specifier = ">=0.25.0" },
     { name = "python-dotenv", specifier = ">=1.1.1" },
     { name = "requests-oauthlib", specifier = ">=2.0.0" },
     { name = "sqlalchemy", extras = ["asyncio"], specifier = ">=2.0.44" },
 ]
+provides-extras = ["test"]
 
 [[package]]
 name = "multidict"
@@ -627,6 +658,24 @@ wheels = [
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+[[package]]
+name = "packaging"
+version = "25.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/a1/d4/1fc4078c65507b51b96ca8f8c3ba19e6a61c8253c72794544580a7b6c24d/packaging-25.0.tar.gz", hash = "sha256:d443872c98d677bf60f6a1f2f8c1cb748e8fe762d2bf9d3148b5599295b0fc4f", size = 165727, upload-time = "2025-04-19T11:48:59.673Z" }
+wheels = [
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+]
+
+[[package]]
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+version = "1.6.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/f9/e2/3e91f31a7d2b083fe6ef3fa267035b518369d9511ffab804f839851d2779/pluggy-1.6.0.tar.gz", hash = "sha256:7dcc130b76258d33b90f61b658791dede3486c3e6bfb003ee5c9bfb396dd22f3", size = 69412, upload-time = "2025-05-15T12:30:07.975Z" }
+wheels = [
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+]
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