Disable HTTP/2 in httpx client for OpenAI and DeepSeek to avoid 421 Misdirected Request errors and ensure consistent connections in HF Spaces

app.py

@@ -83,12 +83,21 @@ def run_network_diagnostics():
     try:
         import httpx
         print(f"  httpx version: {httpx.__version__}")
+        # Test with default settings
         with httpx.Client(timeout=10) as client:
             resp = client.get("https://api.anthropic.com")
-            print(f"  ✅ httpx -> Anthropic HTTP {resp.status_code}")
-        with httpx.Client(timeout=10) as client:
+            print(f"  ✅ httpx (default) -> Anthropic HTTP {resp.status_code}")
+        # Test OpenAI with HTTP/2 disabled (avoids 421 Misdirected Request)
+        with httpx.Client(timeout=10, http2=False) as client:
             resp = client.get("https://api.openai.com")
-            print(f"  ✅ httpx -> OpenAI HTTP {resp.status_code}")
+            print(f"  ✅ httpx (http1.1) -> OpenAI HTTP {resp.status_code}")
+        # Also test with default HTTP/2 to compare
+        try:
+            with httpx.Client(timeout=10) as client:
+                resp = client.get("https://api.openai.com")
+                print(f"  ✅ httpx (default) -> OpenAI HTTP {resp.status_code}")
+        except Exception as e2:
+            print(f"  ⚠️ httpx (default/http2) -> OpenAI FAILED: {type(e2).__name__}: {e2}")
     except Exception as e:
         print(f"  ❌ httpx -> {type(e).__name__}: {e}")
     

main.py

@@ -279,13 +279,15 @@ class LLMAnalyzer:
         if provider == ModelProvider.OPENAI:
             if not OPENAI_API_KEY:
                 raise ValueError(f"OpenAI API key not configured. Please set OPENAI_API_KEY environment variable to use {provider.value} provider.")
-            # Use default httpx settings for better compatibility with async environments
-            self.client = openai.OpenAI(api_key=OPENAI_API_KEY, timeout=120.0)
+            # Disable HTTP/2 to avoid 421 Misdirected Request on HF Spaces
+            self._http_client = httpx.Client(timeout=httpx.Timeout(120.0, connect=30.0), http2=False)
+            self.client = openai.OpenAI(api_key=OPENAI_API_KEY, http_client=self._http_client)
         elif provider == ModelProvider.DEEPSEEK:
             if not DEEPSEEK_API_KEY:
                 raise ValueError(f"DeepSeek API key not configured. Please set DEEPSEEK_API_KEY environment variable to use {provider.value} provider.")
-            # Use default httpx settings for better compatibility with async environments
-            self.client = openai.OpenAI(api_key=DEEPSEEK_API_KEY, base_url="https://api.deepseek.com", timeout=120.0)
+            # Disable HTTP/2 for consistent connections
+            self._http_client = httpx.Client(timeout=httpx.Timeout(120.0, connect=30.0), http2=False)
+            self.client = openai.OpenAI(api_key=DEEPSEEK_API_KEY, base_url="https://api.deepseek.com", http_client=self._http_client)
         elif provider == ModelProvider.ANTHROPIC:
             if not ANTHROPIC_API_KEY:
                 raise ValueError(f"Anthropic API key not configured. Please set ANTHROPIC_API_KEY environment variable to use {provider.value} provider.")
@@ -682,12 +684,14 @@ def generate_legal_position(
             raise Exception(f"Текст судового рішення занадто короткий або відсутній (довжина: {len(court_decision_text) if court_decision_text else 0} символів). Будь ласка, перевірте вхідні дані.")
 
         if provider == ModelProvider.OPENAI.value:
-            # Use context-managed httpx client to avoid socket/fd leaks in threaded Gradio env
+            # Use custom httpx client with HTTP/2 disabled to avoid 421 Misdirected Request
+            # errors on HF Spaces (Cloudflare HTTP/2 connection coalescing issue)
             http_client = None
             response_text = None
             try:
                 http_client = httpx.Client(
                     timeout=httpx.Timeout(120.0, connect=30.0),
+                    http2=False,
                 )
                 client = OpenAI(
                     api_key=OPENAI_API_KEY, 
@@ -779,12 +783,13 @@ def generate_legal_position(
                         pass
 
         if provider == ModelProvider.DEEPSEEK.value:
-            # Use context-managed httpx client for DeepSeek to avoid socket/fd leaks
+            # Use custom httpx client with HTTP/2 disabled for consistent connections
             http_client = None
             response_text = None
             try:
                 http_client = httpx.Client(
                     timeout=httpx.Timeout(120.0, connect=30.0),
+                    http2=False,
                 )
                 client = OpenAI(
                     api_key=DEEPSEEK_API_KEY,