diff --git a/cerulean_cloud/cloud_run_tipg/handler.py b/cerulean_cloud/cloud_run_tipg/handler.py
index 1073c30a..4012aead 100644
--- a/cerulean_cloud/cloud_run_tipg/handler.py
+++ b/cerulean_cloud/cloud_run_tipg/handler.py
@@ -10,13 +10,15 @@
 
 """
 import logging
+import os
 from typing import Any, List, Optional
 
 import asyncpg
 import jinja2
 import pydantic
-from fastapi import FastAPI
+from fastapi import FastAPI, HTTPException
 from mangum import Mangum
+from starlette.middleware.base import BaseHTTPMiddleware
 from starlette.middleware.cors import CORSMiddleware
 from starlette.requests import Request
 from starlette.templating import Jinja2Templates
@@ -33,6 +35,80 @@
 db_settings = DatabaseSettings()
 
 
+def extract_table_from_request(request: Request) -> Optional[str]:
+    """
+    Extract the collection ID (table name) from the URL path of an incoming HTTP request.
+
+    Args:
+        request (Request): The incoming FastAPI request object.
+
+    Returns:
+        Optional[str]: The collection ID if present in the URL path; otherwise, None.
+
+    Example:
+        Given a request object with URL 'http://localhost:8000/collections/my_table/items',
+        this function will return 'my_table'.
+    """
+    path_parts = request.url.split("/")
+
+    # Check if the request is related to collections
+    if "collections" in path_parts:
+        idx = path_parts.index("collections")
+
+        # The 'collectionId' should be the segment immediately following 'collections'
+        if len(path_parts) > idx + 1:
+            return path_parts[idx + 1]
+
+    # Return None if 'collectionId' is not found
+    return None
+
+
+def get_env_list(env_var: str, default: List[str] = None) -> List[str]:
+    """Get a list from an environment variable. Assumes values are comma-separated."""
+    raw_value = os.environ.get(env_var)
+    if raw_value is None:
+        return default if default is not None else []
+    return raw_value.split(",")
+
+
+class AccessControlMiddleware(BaseHTTPMiddleware):
+    """
+    Middleware to handle access control based on the collection ID and an API key.
+
+    This middleware calls `extract_table_from_request` to determine the collection ID
+    from the request. It then checks if this collection is in the list of excluded collections.
+    If so, it verifies the API key in the request headers. If the API key is invalid,
+    it raises an HTTP 403 exception.
+    """
+
+    async def dispatch(self, request: Request, call_next):
+        """
+        The dispatch method to handle the request and execute the middleware logic.
+
+        Args:
+            request (Request): The incoming FastAPI request object.
+            call_next: The next middleware or endpoint in the processing pipeline.
+
+        Raises:
+            HTTPException: If the collection is restricted and an invalid API key is provided.
+
+        Returns:
+            Response: The outgoing FastAPI response object.
+        """
+        table = extract_table_from_request(request)
+        excluded_collections = get_env_list("TIPG_DB_EXCLUDE_TABLES") + get_env_list(
+            "TIPG_DB_EXCLUDE_FUNCTIONS"
+        )
+        if table in excluded_collections:
+            api_key = request.headers.get("X-API-Key")
+            if not api_key == "XXX_SECRET_API_KEY":
+                raise HTTPException(
+                    status_code=403, detail="Access to table restricted"
+                )
+        response = await call_next(request)
+        return response
+
+
 class PostgresSettings(pydantic.BaseSettings):
     """Postgres-specific API settings.
 
@@ -102,6 +178,9 @@ class Config:
         allow_headers=["*"],
     )
 
+# Custom API key checking for restricted access
+app.add_middleware(AccessControlMiddleware)
+
 app.add_middleware(CacheControlMiddleware, cachecontrol=settings.cachecontrol)
 app.add_middleware(CompressionMiddleware)
 add_exception_handlers(app, DEFAULT_STATUS_CODES)