rebase

app/core/llm.py

@@ -141,16 +141,36 @@ class LlmClient:
                     )
                 if resp.status_code >= 500:
                     raise LLMUnavailableError(
-                        f"LLM provider returned {resp.status_code}: {resp.text[:200]}"
+                        f"LLM provider returned HTTP {resp.status_code}: {resp.text[:300]}"
                     )
                 if resp.status_code == 429:
-                    raise LLMUnavailableError("LLM provider rate-limited (429)")
+                    raise LLMUnavailableError("LLM provider rate-limited (HTTP 429)")
                 if resp.status_code >= 400:
+                    # Try to extract error message from JSON body
+                    err_body = resp.text[:500]
+                    try:
+                        err_json = resp.json()
+                        if "error" in err_json:
+                            err_msg = err_json["error"].get("message", err_body)
+                        else:
+                            err_msg = err_body
+                    except Exception:  # noqa: BLE001
+                        err_msg = err_body
                     raise LLMResponseError(
-                        f"LLM provider returned {resp.status_code}: {resp.text[:500]}",
+                        f"LLM provider returned HTTP {resp.status_code}: {err_msg}",
                         code="api_error",
                     )
-                data = resp.json()
+                # Parse JSON response — if this fails, the URL is likely wrong
+                # (pointing at an HTML page instead of an OpenAI-compatible API)
+                try:
+                    data = resp.json()
+                except Exception as e:  # noqa: BLE001
+                    raise LLMResponseError(
+                        f"LLM provider returned non-JSON response (check that "
+                        f"api_url points to an OpenAI-compatible endpoint). "
+                        f"First 200 chars: {resp.text[:200]}",
+                        code="parse_error",
+                    ) from e
                 break
             except (httpx.TimeoutException, asyncio.TimeoutError) as e:
                 last_exc = LLMTimeoutError(str(e))