diff --git a/tests/pass_through_tests/test_anthropic_passthrough.py b/tests/pass_through_tests/test_anthropic_passthrough.py
index d5f2a2433..277adcdb9 100644
--- a/tests/pass_through_tests/test_anthropic_passthrough.py
+++ b/tests/pass_through_tests/test_anthropic_passthrough.py
@@ -5,6 +5,8 @@ This test ensures that the proxy can passthrough anthropic requests
 
 import pytest
 import anthropic
+import aiohttp
+import asyncio
 
 client = anthropic.Anthropic(
     base_url="http://0.0.0.0:4000/anthropic", api_key="sk-1234"
@@ -47,3 +49,211 @@ def test_anthropic_streaming():
 
     full_response = "".join(collected_output)
     print(full_response)
+
+
+@pytest.mark.asyncio
+async def test_anthropic_basic_completion_with_headers():
+    print("making basic completion request to anthropic passthrough with aiohttp")
+
+    headers = {
+        "Authorization": f"Bearer sk-1234",
+        "Content-Type": "application/json",
+        "Anthropic-Version": "2023-06-01",
+    }
+
+    payload = {
+        "model": "claude-3-5-sonnet-20241022",
+        "max_tokens": 10,
+        "messages": [{"role": "user", "content": "Say 'hello test' and nothing else"}],
+        "litellm_metadata": {
+            "tags": ["test-tag-1", "test-tag-2"],
+        },
+    }
+
+    async with aiohttp.ClientSession() as session:
+        async with session.post(
+            "http://0.0.0.0:4000/anthropic/v1/messages", json=payload, headers=headers
+        ) as response:
+            response_text = await response.text()
+            print(f"Response text: {response_text}")
+
+            response_json = await response.json()
+            response_headers = response.headers
+            litellm_call_id = response_headers.get("x-litellm-call-id")
+
+            print(f"LiteLLM Call ID: {litellm_call_id}")
+
+            # Wait for spend to be logged
+            await asyncio.sleep(15)
+
+            # Check spend logs for this specific request
+            async with session.get(
+                f"http://0.0.0.0:4000/spend/logs?request_id={litellm_call_id}",
+                headers={"Authorization": "Bearer sk-1234"},
+            ) as spend_response:
+                print("text spend response")
+                print(f"Spend response: {spend_response}")
+                spend_data = await spend_response.json()
+                print(f"Spend data: {spend_data}")
+                assert spend_data is not None, "Should have spend data for the request"
+
+                log_entry = spend_data[
+                    0
+                ]  # Get the first (and should be only) log entry
+
+                # Basic existence checks
+                assert spend_data is not None, "Should have spend data for the request"
+                assert isinstance(log_entry, dict), "Log entry should be a dictionary"
+
+                # Request metadata assertions
+                assert (
+                    log_entry["request_id"] == litellm_call_id
+                ), "Request ID should match"
+                assert (
+                    log_entry["call_type"] == "pass_through_endpoint"
+                ), "Call type should be pass_through_endpoint"
+                assert (
+                    log_entry["api_base"] == "https://api.anthropic.com/v1/messages"
+                ), "API base should be Anthropic's endpoint"
+
+                # Token and spend assertions
+                assert log_entry["spend"] > 0, "Spend value should not be None"
+                assert isinstance(
+                    log_entry["spend"], (int, float)
+                ), "Spend should be a number"
+                assert log_entry["total_tokens"] > 0, "Should have some tokens"
+                assert log_entry["prompt_tokens"] > 0, "Should have prompt tokens"
+                assert (
+                    log_entry["completion_tokens"] > 0
+                ), "Should have completion tokens"
+                assert (
+                    log_entry["total_tokens"]
+                    == log_entry["prompt_tokens"] + log_entry["completion_tokens"]
+                ), "Total tokens should equal prompt + completion"
+
+                # Time assertions
+                assert all(
+                    key in log_entry
+                    for key in ["startTime", "endTime", "completionStartTime"]
+                ), "Should have all time fields"
+                assert (
+                    log_entry["startTime"] < log_entry["endTime"]
+                ), "Start time should be before end time"
+
+                # Metadata assertions
+                assert log_entry["cache_hit"] == "False", "Cache should be off"
+                assert log_entry["request_tags"] == [
+                    "test-tag-1",
+                    "test-tag-2",
+                ], "Tags should match input"
+                assert (
+                    "user_api_key" in log_entry["metadata"]
+                ), "Should have user API key in metadata"
+
+
+@pytest.mark.asyncio
+async def test_anthropic_streaming_with_headers():
+    print("making streaming request to anthropic passthrough with aiohttp")
+
+    headers = {
+        "Authorization": f"Bearer sk-1234",
+        "Content-Type": "application/json",
+        "Anthropic-Version": "2023-06-01",
+    }
+
+    payload = {
+        "model": "claude-3-5-sonnet-20241022",
+        "max_tokens": 10,
+        "messages": [
+            {"role": "user", "content": "Say 'hello stream test' and nothing else"}
+        ],
+        "stream": True,
+        "litellm_metadata": {
+            "tags": ["test-tag-stream-1", "test-tag-stream-2"],
+        },
+    }
+
+    async with aiohttp.ClientSession() as session:
+        async with session.post(
+            "http://0.0.0.0:4000/anthropic/v1/messages", json=payload, headers=headers
+        ) as response:
+            print("response status")
+            print(response.status)
+            assert response.status == 200, "Response should be successful"
+            response_headers = response.headers
+            print(f"Response headers: {response_headers}")
+            litellm_call_id = response_headers.get("x-litellm-call-id")
+            print(f"LiteLLM Call ID: {litellm_call_id}")
+
+            collected_output = []
+            async for line in response.content:
+                if line:
+                    text = line.decode("utf-8").strip()
+                    if text.startswith("data: "):
+                        collected_output.append(text[6:])  # Remove 'data: ' prefix
+
+            print("Collected output:", "".join(collected_output))
+
+            # Wait for spend to be logged
+            await asyncio.sleep(20)
+
+            # Check spend logs for this specific request
+            async with session.get(
+                f"http://0.0.0.0:4000/spend/logs?request_id={litellm_call_id}",
+                headers={"Authorization": "Bearer sk-1234"},
+            ) as spend_response:
+                spend_data = await spend_response.json()
+                print(f"Spend data: {spend_data}")
+                assert spend_data is not None, "Should have spend data for the request"
+
+                log_entry = spend_data[
+                    0
+                ]  # Get the first (and should be only) log entry
+
+                # Basic existence checks
+                assert spend_data is not None, "Should have spend data for the request"
+                assert isinstance(log_entry, dict), "Log entry should be a dictionary"
+
+                # Request metadata assertions
+                assert (
+                    log_entry["request_id"] == litellm_call_id
+                ), "Request ID should match"
+                assert (
+                    log_entry["call_type"] == "pass_through_endpoint"
+                ), "Call type should be pass_through_endpoint"
+                assert (
+                    log_entry["api_base"] == "https://api.anthropic.com/v1/messages"
+                ), "API base should be Anthropic's endpoint"
+
+                # Token and spend assertions
+                assert log_entry["spend"] > 0, "Spend value should not be None"
+                assert isinstance(
+                    log_entry["spend"], (int, float)
+                ), "Spend should be a number"
+                assert log_entry["total_tokens"] > 0, "Should have some tokens"
+                assert (
+                    log_entry["completion_tokens"] > 0
+                ), "Should have completion tokens"
+                assert (
+                    log_entry["total_tokens"]
+                    == log_entry["prompt_tokens"] + log_entry["completion_tokens"]
+                ), "Total tokens should equal prompt + completion"
+
+                # Time assertions
+                assert all(
+                    key in log_entry
+                    for key in ["startTime", "endTime", "completionStartTime"]
+                ), "Should have all time fields"
+                assert (
+                    log_entry["startTime"] < log_entry["endTime"]
+                ), "Start time should be before end time"
+
+                # Metadata assertions
+                assert log_entry["cache_hit"] == "False", "Cache should be off"
+                assert log_entry["request_tags"] == [
+                    "test-tag-stream-1",
+                    "test-tag-stream-2",
+                ], "Tags should match input"
+                assert (
+                    "user_api_key" in log_entry["metadata"]
+                ), "Should have user API key in metadata"