Upload http_client.py

src/services/http_client.py

@@ -0,0 +1,39 @@
+"""Shared outbound HTTP client factory.
+
+Hugging Face Spaces resolve some hosts to IPv6 addresses they cannot actually
+route, which surfaces as httpx.ConnectTimeout('') with no message - the socket
+never opens. Binding the local address to 0.0.0.0 forces IPv4 and avoids the
+dead AAAA path. Transport-level retries cover transient DNS/SYN loss.
+
+Use make_client() for every outbound call to infrastructure we control
+(the Cloudflare Worker). Third-party APIs that already work are unaffected.
+"""
+import logging
+from typing import Optional
+
+import httpx
+
+logger = logging.getLogger(__name__)
+
+# Set to None to let the OS choose (dual-stack); "0.0.0.0" forces IPv4.
+FORCE_IPV4_LOCAL_ADDRESS: Optional[str] = "0.0.0.0"
+
+
+def make_transport(retries: int = 2) -> httpx.AsyncHTTPTransport:
+    try:
+        return httpx.AsyncHTTPTransport(
+            local_address=FORCE_IPV4_LOCAL_ADDRESS,
+            retries=retries,
+        )
+    except Exception as exc:  # very old httpx without local_address
+        logger.warning(f"IPv4-forcing transport unavailable ({exc}); using default")
+        return httpx.AsyncHTTPTransport(retries=retries)
+
+
+def make_client(timeout: float = 8.0, retries: int = 2) -> httpx.AsyncClient:
+    """AsyncClient pinned to IPv4 with transport retries."""
+    return httpx.AsyncClient(
+        timeout=timeout,
+        transport=make_transport(retries=retries),
+        follow_redirects=True,
+    )