diff --git a/src/providers/index.ts b/src/providers/index.ts
index e724dd7..a9d4638 100644
--- a/src/providers/index.ts
+++ b/src/providers/index.ts
@@ -1,9 +1,10 @@
 import { azureOpenAIProvider } from './azureOpenAI';
 import { workersAIProvider } from './workersAI';
 import { deepseekProvider } from './deepseek';
-
+import { openaiProvider } from './openai';
 export const providers = {
   'azure-openai': azureOpenAIProvider,
   'workers-ai': workersAIProvider,
   'deepseek': deepseekProvider,
-};
\ No newline at end of file
+  'openai': openaiProvider,
+};
diff --git a/src/providers/openai.ts b/src/providers/openai.ts
new file mode 100644
index 0000000..5d2c2d5
--- /dev/null
+++ b/src/providers/openai.ts
@@ -0,0 +1,115 @@
+import { Hono, Context, Next } from 'hono';
+import { AIProvider } from '../types';
+import {
+    cacheMiddleware,
+    metricsMiddleware,
+    bufferMiddleware,
+    loggingMiddleware,
+    virtualKeyMiddleware,
+    rateLimiterMiddleware,
+    guardMiddleware,
+    fallbackMiddleware
+} from '../middlewares';
+
+const BasePath = '/openai';
+const ProviderName = 'openai';
+const openaiRoute = new Hono();
+
+const initMiddleware = async (c: Context, next: Next) => {
+    c.set('endpoint', ProviderName);
+    c.set('getModelName', getModelName);
+    c.set('getTokenCount', getTokenCount);
+    c.set('getVirtualKey', getVirtualKey);
+    await next();
+};
+
+openaiRoute.use(
+    initMiddleware,
+    metricsMiddleware,
+    loggingMiddleware,
+    bufferMiddleware,
+    virtualKeyMiddleware,
+    rateLimiterMiddleware,
+    guardMiddleware,
+    cacheMiddleware,
+    fallbackMiddleware
+);
+
+openaiRoute.post('/*', async (c: Context) => {
+    return openaiProvider.handleRequest(c);
+});
+
+openaiRoute.get('/*', async (c: Context) => {
+    return c.text('OpenAI endpoint on Malacca.', 200, { 'Content-Type': 'text/plain' });
+});
+
+export const openaiProvider: AIProvider = {
+    name: ProviderName,
+    basePath: BasePath,
+    route: openaiRoute,
+    getModelName: getModelName,
+    getTokenCount: getTokenCount,
+    handleRequest: async (c: Context) => {
+        const functionName = c.req.path.slice(`/openai/`.length);
+        const openaiEndpoint = `https://api.openai.com/${functionName}`;
+        console.log('openaiEndpoint', openaiEndpoint);
+        const headers = new Headers(c.req.header());
+        if (c.get('middlewares')?.includes('virtualKey')) {
+            const apiKey: string = c.get('realKey');
+            if (apiKey) {
+                headers.set('Authorization', `Bearer ${apiKey}`);
+            }
+        }
+
+        const response = await fetch(openaiEndpoint, {
+            method: c.req.method,
+            body: JSON.stringify(await c.req.json()),
+            headers: headers
+        });
+
+        return response;
+    }
+};
+
+function getModelName(c: Context): string {
+    const body = c.get('reqBuffer') || '{}';
+    const model = JSON.parse(body).model;
+    return model || "unknown";
+}
+
+function getTokenCount(c: Context): { input_tokens: number, output_tokens: number } {
+    const buf = c.get('buffer') || "";
+    if (c.res.status === 200) {
+        if (c.res.headers.get('content-type') === 'application/json') {
+            try {
+                const jsonResponse = JSON.parse(buf);
+            const usage = jsonResponse.usage;
+            if (usage) {
+                return {
+                    input_tokens: usage.prompt_tokens || 0,
+                    output_tokens: usage.completion_tokens || 0
+                };
+            }
+        } catch (error) {
+                console.error("Error parsing response:", error);
+            }
+        }
+        else {
+            const output = buf.trim().split('\n\n').at(-2);
+            if (output && output.startsWith('data: ')) {
+                const usage_message = JSON.parse(output.slice('data: '.length));
+                return {
+                    input_tokens: usage_message.usage.prompt_tokens || 0,
+                    output_tokens: usage_message.usage.completion_tokens || 0
+                };
+            }
+        }
+    } 
+    return { input_tokens: 0, output_tokens: 0 };
+}
+
+function getVirtualKey(c: Context): string {
+    const authHeader = c.req.header('Authorization') || '';
+    return authHeader.startsWith('Bearer ') ? authHeader.slice(7) : '';
+}
+
diff --git a/test/openai.test.ts b/test/openai.test.ts
new file mode 100644
index 0000000..a807a00
--- /dev/null
+++ b/test/openai.test.ts
@@ -0,0 +1,136 @@
+/// <reference types="vite/client" />
+/// <reference path="../worker-configuration.d.ts" />
+import { env, SELF } from 'cloudflare:test';
+import { beforeAll, describe, it, expect } from 'vitest';
+
+declare module "cloudflare:test" {
+    interface ProvidedEnv extends Env { }
+}
+
+beforeAll(async () => {
+    await env.MALACCA_USER.put('openai', import.meta.env.VITE_OPENAI_API_KEY);
+});
+
+const url = `https://example.com/openai/v1/chat/completions`;
+
+const createRequestBody = (stream: boolean, placeholder: string) => `
+{
+  "model": "gpt-4o-mini",
+  "messages": [
+    {
+      "role": "system",
+      "content":  "You are an AI assistant that helps people find information."
+    },
+    {
+      "role": "user",
+      "content":  "Tell me a very short story about ${placeholder}"
+    }
+  ],
+  "temperature": 0.7,
+  "top_p": 0.95,
+  "max_tokens": 100,
+  "stream": ${stream}
+}`;
+
+describe('Test Virtual Key', () => {
+    it('should return 401 for invalid api key', async () => {
+        const response = await SELF.fetch(url, {
+            method: 'POST',
+            body: createRequestBody(true, 'Malacca'),
+            headers: { 'Content-Type': 'application/json', 'Authorization': 'Bearer invalid-key' }
+        });
+
+        expect(response.status).toBe(401);
+    });
+});
+
+describe('Test Guard', () => {
+    it('should return 403 for deny request', async () => {
+        const response = await SELF.fetch(url, {
+            method: 'POST',
+            body: createRequestBody(true, 'password'),
+            headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer openai` }
+        });
+
+        expect(response.status).toBe(403);
+    });
+});
+
+describe('Test Cache', () => {
+    it('with cache first response should with no header malacca-cache-status and following response with hit', async () => {
+      const body = createRequestBody(false, 'Malacca');
+      let start = Date.now();
+      let response = await SELF.fetch(url, { method: 'POST', body: body, headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer openai` } });
+      const value = await response.json()
+      const duration = Date.now() - start
+  
+      expect(response.status).toBe(200);
+      expect(response.headers.get('content-type')).toContain('application/json');
+      expect(response.headers.get('malacca-cache-status')).toBeNull();
+  
+      start = Date.now();
+      response = await SELF.fetch(url, { method: 'POST', body: body, headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer openai` } });
+      const cacheValue = await response.json()
+      const cacheDuration = Date.now() - start
+  
+      expect(response.status).toBe(200);
+      expect(response.headers.get('malacca-cache-status')).toBe('hit');
+      expect(response.headers.get('content-type')).toBe('application/json');
+      expect(value).toEqual(cacheValue)
+      expect(duration / 2).toBeGreaterThan(cacheDuration)
+    });
+  
+    it('Test stream with cache', async () => {
+      const body = createRequestBody(true, 'Malacca');
+      let start = Date.now();
+      let response = await SELF.fetch(url, { method: 'POST', body: body, headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer openai` } });
+      const value = await response.text()
+      const duration = Date.now() - start
+  
+      expect(response.status).toBe(200);
+      expect(response.headers.get('content-type')).toContain('text/event-stream');
+      expect(response.headers.get('malacca-cache-status')).toBeNull();
+  
+      start = Date.now();
+      response = await SELF.fetch(url, { method: 'POST', body: body, headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer openai` } });
+      const cacheValue = await response.text()
+      const cacheDuration = Date.now() - start
+  
+      expect(response.status).toBe(200);
+      expect(response.headers.get('malacca-cache-status')).toBe('hit');
+      expect(response.headers.get('content-type')).toContain('text/event-stream');
+      expect(value).toEqual(cacheValue)
+      expect(duration / 2).toBeGreaterThan(cacheDuration)
+    });
+  
+    it('should not cache non-200 responses', async () => {
+      const invalidBody = JSON.stringify({
+        messages: [{ role: "user", content: "This is an invalid request" }],
+        stream: "invalid-model",
+        temperature: 0.7,
+        top_p: 0.95,
+        max_tokens: 800,
+      });
+  
+      // First request - should return a non-200 response
+      let response = await SELF.fetch(url, {
+        method: 'POST',
+        body: invalidBody,
+        headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer openai` }
+      });
+  
+      expect(response.status).not.toBe(200);
+      expect(response.headers.get('malacca-cache-status')).toBeNull();
+  
+      // Second request with the same invalid body
+      response = await SELF.fetch(url, {
+        method: 'POST',
+        body: invalidBody,
+        headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer openai` }
+      });
+  
+      expect(response.status).not.toBe(200);
+      // Should still be a cache miss, as non-200 responses are not cached
+      expect(response.headers.get('malacca-cache-status')).toBeNull();
+    });
+  });
\ No newline at end of file