diff --git a/cc-haha/src/server/proxy/handler.ts b/cc-haha/src/server/proxy/handler.ts
index 36bf7ba..dc3dbe7 100644
--- a/cc-haha/src/server/proxy/handler.ts
+++ b/cc-haha/src/server/proxy/handler.ts
@@ -18,6 +18,17 @@ import { openaiChatStreamToAnthropic } from './streaming/openaiChatStreamToAnthr
 import { openaiResponsesStreamToAnthropic } from './streaming/openaiResponsesStreamToAnthropic.js'
 import type { AnthropicRequest } from './transform/types.js'
 
+/**
+ * Patch thinking parameter for newer Claude models (4.x / Opus 4.7+).
+ * These models require `thinking.type = "adaptive"` instead of `"enabled"`.
+ */
+function patchThinkingForModel(body: AnthropicRequest): void {
+  if (!body.thinking) return
+  if (body.thinking.type === 'enabled') {
+    body.thinking.type = 'adaptive'
+  }
+}
+
 const providerService = new ProviderService()
 
 export async function handleProxyRequest(req: Request, url: URL): Promise<Response> {
@@ -53,21 +64,6 @@ export async function handleProxyRequest(req: Request, url: URL): Promise<Respon
     )
   }
 
-  if (config.apiFormat === 'anthropic') {
-    return Response.json(
-      {
-        type: 'error',
-        error: {
-          type: 'invalid_request_error',
-          message: providerId
-            ? `Provider "${providerId}" uses anthropic format — proxy not needed`
-            : 'Active provider uses anthropic format — proxy not needed',
-        },
-      },
-      { status: 400 },
-    )
-  }
-
   // Parse request body
   let body: AnthropicRequest
   try {
@@ -82,8 +78,13 @@ export async function handleProxyRequest(req: Request, url: URL): Promise<Respon
   const isStream = body.stream === true
   const baseUrl = config.baseUrl.replace(/\/+$/, '')
 
+  // Always patch thinking parameter for newer models
+  patchThinkingForModel(body)
+
   try {
-    if (config.apiFormat === 'openai_chat') {
+    if (config.apiFormat === 'anthropic') {
+      return await handleAnthropicPassthrough(req, body, baseUrl, config.apiKey, isStream)
+    } else if (config.apiFormat === 'openai_chat') {
       return await handleOpenaiChat(body, baseUrl, config.apiKey, isStream)
     } else {
       return await handleOpenaiResponses(body, baseUrl, config.apiKey, isStream)
@@ -103,6 +104,50 @@ export async function handleProxyRequest(req: Request, url: URL): Promise<Respon
   }
 }
 
+async function handleAnthropicPassthrough(
+  originalReq: Request,
+  body: AnthropicRequest,
+  baseUrl: string,
+  apiKey: string,
+  isStream: boolean,
+): Promise<Response> {
+  const url = `${baseUrl}/v1/messages`
+
+  const headers: Record<string, string> = {
+    'Content-Type': 'application/json',
+    'x-api-key': apiKey,
+    'anthropic-version': originalReq.headers.get('anthropic-version') || '2023-06-01',
+  }
+  const authHeader = originalReq.headers.get('authorization')
+  if (authHeader) {
+    headers['Authorization'] = authHeader
+  }
+
+  const upstream = await fetch(url, {
+    method: 'POST',
+    headers,
+    body: JSON.stringify(body),
+    signal: AbortSignal.timeout(600_000),
+  })
+
+  if (isStream && upstream.ok && upstream.body) {
+    return new Response(upstream.body, {
+      status: upstream.status,
+      headers: {
+        'Content-Type': upstream.headers.get('Content-Type') || 'text/event-stream',
+        'Cache-Control': 'no-cache',
+        Connection: 'keep-alive',
+      },
+    })
+  }
+
+  const text = await upstream.text()
+  return new Response(text, {
+    status: upstream.status,
+    headers: { 'Content-Type': 'application/json; charset=utf-8' },
+  })
+}
+
 async function handleOpenaiChat(
   body: AnthropicRequest,
   baseUrl: string,
diff --git a/cc-haha/src/server/services/providerService.ts b/cc-haha/src/server/services/providerService.ts
index e72208a..815f787 100644
--- a/cc-haha/src/server/services/providerService.ts
+++ b/cc-haha/src/server/services/providerService.ts
@@ -247,7 +247,7 @@ export class ProviderService {
     provider: SavedProvider,
     options?: { proxyPath?: string },
   ): Record<string, string> {
-    const needsProxy = provider.apiFormat != null && provider.apiFormat !== 'anthropic'
+    const needsProxy = provider.apiFormat != null
     const proxyPath = options?.proxyPath ?? '/proxy'
     const baseUrl = needsProxy
       ? `http://127.0.0.1:${ProviderService.serverPort}${proxyPath}`