diff --git a/indexify/tests/src/tests/test_function_allowlist.py b/indexify/tests/src/tests/test_function_allowlist.py
new file mode 100644
index 000000000..dca9f8d82
--- /dev/null
+++ b/indexify/tests/src/tests/test_function_allowlist.py
@@ -0,0 +1,127 @@
+import os
+import subprocess
+import time
+import unittest
+from typing import List, Optional
+
+from indexify import Graph, indexify_function
+from indexify.remote_graph import RemoteGraph
+from tests.utils import (
+    ExecutorProcessContextManager,
+    fetch_dev_mode_executor_pid,
+    function_uri,
+)
+
+# There's a dev mode executor already running in the testing environment.
+# It's used for all other tests that don't check the function allowlist.
+# This existing Executor can run any function.
+dev_mode_executor_pid: Optional[int] = None
+# This Executor can only run function_a.
+function_a_executor_pid: Optional[int] = None
+# This Executor can only run function_b.
+function_b_executor_pid: Optional[int] = None
+
+
+@indexify_function()
+def function_a() -> str:
+    global dev_mode_executor_pid
+    global function_a_executor_pid
+    global function_b_executor_pid
+
+    # Assuming Subprocess Function Executors are used in Open Source.
+    current_executor_pid: int = os.getppid()
+    allowed_executor_pids: List[int] = [function_a_executor_pid, dev_mode_executor_pid]
+    if current_executor_pid not in allowed_executor_pids:
+        raise Exception(
+            f"Function A Executor PID {current_executor_pid} is not in the allowlist: {allowed_executor_pids}"
+        )
+    return "success"
+
+
+@indexify_function()
+def function_b(_: str) -> str:
+    global dev_mode_executor_pid
+    global function_a_executor_pid
+    global function_b_executor_pid
+
+    # Assuming Subprocess Function Executors are used in Open Source.
+    current_executor_pid: int = os.getppid()
+    allowed_executor_pids: List[int] = [function_b_executor_pid, dev_mode_executor_pid]
+    if current_executor_pid not in allowed_executor_pids:
+        raise Exception(
+            f"Function B Executor PID {current_executor_pid} is not in the allowlist: {allowed_executor_pids}"
+        )
+    return "success"
+
+
+class TestFunctionAllowlist(unittest.TestCase):
+    def test_different_executors_run_different_functions(self):
+        global dev_mode_executor_pid
+        dev_mode_executor_pid = fetch_dev_mode_executor_pid()
+        print(f"Found dev mode Executor PID: {dev_mode_executor_pid}")
+
+        with ExecutorProcessContextManager(
+            [
+                "--function",
+                function_uri(
+                    "default",
+                    "test_different_executors_run_different_functions",
+                    "function_a",
+                    "1.0",
+                ),
+                "--ports",
+                "60000",
+                "60001",
+            ]
+        ) as executor_a:
+            executor_a: subprocess.Popen
+            global function_a_executor_pid
+            function_a_executor_pid = executor_a.pid
+            print(f"Started Executor A with PID: {function_a_executor_pid}")
+
+            with ExecutorProcessContextManager(
+                [
+                    "--function",
+                    function_uri(
+                        "default",
+                        "test_different_executors_run_different_functions",
+                        "function_b",
+                        "1.0",
+                    ),
+                    "--ports",
+                    "60001",
+                    "60002",
+                ]
+            ) as executor_b:
+                executor_b: subprocess.Popen
+                global function_b_executor_pid
+                function_b_executor_pid = executor_b.pid
+                print(f"Started Executor B with PID: {function_b_executor_pid}")
+
+                # Wait to let Executor A and B start and register at the Server.
+                time.sleep(5)
+
+                graph = Graph(
+                    name="test_different_executors_run_different_functions",
+                    description="test",
+                    start_node=function_a,
+                    version="1.0",
+                )
+                graph.add_edge(function_a, function_b)
+                graph = RemoteGraph.deploy(graph)
+
+                # As invocations might land on dev Executor, we need to run the graph multiple times
+                # to ensure that we catch wrong routing to Executor A or B if it ever happens.
+                for _ in range(10):
+                    invocation_id = graph.run(block_until_done=True)
+                    output = graph.output(invocation_id, "function_a")
+                    self.assertEqual(len(output), 1)
+                    self.assertEqual(output[0], "success")
+
+                    output = graph.output(invocation_id, "function_b")
+                    self.assertEqual(len(output), 1)
+                    self.assertEqual(output[0], "success")
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/indexify/tests/src/tests/utils.py b/indexify/tests/src/tests/utils.py
new file mode 100644
index 000000000..a03e88d61
--- /dev/null
+++ b/indexify/tests/src/tests/utils.py
@@ -0,0 +1,32 @@
+import subprocess
+from typing import List, Optional
+
+
+def fetch_dev_mode_executor_pid() -> int:
+    result = subprocess.run(
+        ["pgrep", "-f", "indexify-cli.+executor"],
+        check=True,
+        stdout=subprocess.PIPE,
+        text=True,
+    )
+    return int(result.stdout.strip())
+
+
+def function_uri(namespace: str, graph: str, function: str, version: str) -> str:
+    return ":".join([namespace, graph, function, version])
+
+
+class ExecutorProcessContextManager:
+    def __init__(self, args: List[str]):
+        self._args = ["indexify-cli", "executor"]
+        self._args.extend(args)
+        self._process: Optional[subprocess.Popen] = None
+
+    def __enter__(self) -> subprocess.Popen:
+        self._process = subprocess.Popen(self._args)
+        return self._process
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        if self._process:
+            self._process.terminate()
+            self._process.wait()