diff --git a/fastapi_server/server_openai.py b/fastapi_server/server_openai.py
index 31e96b8..d82a457 100644
--- a/fastapi_server/server_openai.py
+++ b/fastapi_server/server_openai.py
@@ -1,6 +1,7 @@
-from fastapi import FastAPI, HTTPException, Request
+from fastapi import FastAPI, HTTPException, Request, Depends, Security
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import StreamingResponse, JSONResponse
+from fastapi.security import APIKeyHeader
 from pydantic import BaseModel, Field
 from typing import List, Optional, Union, Literal
 import os
@@ -20,6 +21,18 @@ from lang_agent.pipeline import Pipeline, PipelineConfig
 pipeline_config = tyro.cli(PipelineConfig)
 pipeline: Pipeline = pipeline_config.setup()
 
+# API Key Authentication
+API_KEY_HEADER = APIKeyHeader(name="Authorization", auto_error=True)
+VALID_API_KEYS = set(filter(None, os.environ.get("FAST_AUTH_KEYS", "").split(",")))
+
+
+async def verify_api_key(api_key: str = Security(API_KEY_HEADER)):
+    """Verify the API key from Authorization header (Bearer token format)."""
+    key = api_key[7:] if api_key.startswith("Bearer ") else api_key
+    if VALID_API_KEYS and key not in VALID_API_KEYS:
+        raise HTTPException(status_code=401, detail="Invalid API key")
+    return key
+
 
 class OpenAIMessage(BaseModel):
     role: str
@@ -133,7 +146,7 @@ async def sse_chunks_from_astream(chunk_generator, response_id: str, model: str,
 
 
 @app.post("/v1/chat/completions")
-async def chat_completions(request: Request):
+async def chat_completions(request: Request, _: str = Depends(verify_api_key)):
     try:
         body = await request.json()
         
@@ -222,7 +235,7 @@ async def health():
 
 
 @app.delete("/v1/memory")
-async def delete_memory():
+async def delete_memory(_: str = Depends(verify_api_key)):
     """Delete all conversation memory/history."""
     try:
         await pipeline.aclear_memory()