fix(agent): preload jiter native parser

agent/__init__.py

@@ -4,3 +4,5 @@
 that were previously embedded in the 3,600-line run_agent.py. Extracting
 them makes run_agent.py focused on the AIAgent orchestrator class.
 """
+
+from . import jiter_preload as _jiter_preload  # noqa: F401

agent/jiter_preload.py

@@ -0,0 +1,39 @@
+"""Best-effort early import for the OpenAI SDK's native streaming parser.
+
+The OpenAI SDK imports ``jiter`` while constructing streaming chat-completion
+responses.  On some Windows installs the native extension can be imported
+directly from the Hermes venv, but the first import fails when it happens later
+inside the threaded streaming request path.  Loading it once during agent
+package import avoids that import-order failure while preserving the normal
+SDK error path for genuinely missing or broken installs.
+"""
+
+from __future__ import annotations
+
+import importlib
+
+_JITER_PRELOADED = False
+_JITER_PRELOAD_ERROR: Exception | None = None
+
+
+def preload_jiter_native_extension() -> bool:
+    """Import jiter's native extension early if it is available."""
+
+    global _JITER_PRELOADED, _JITER_PRELOAD_ERROR
+
+    if _JITER_PRELOADED:
+        return True
+
+    try:
+        importlib.import_module("jiter.jiter")
+        from jiter import from_json as _from_json  # noqa: F401
+    except Exception as exc:
+        _JITER_PRELOAD_ERROR = exc
+        return False
+
+    _JITER_PRELOADED = True
+    _JITER_PRELOAD_ERROR = None
+    return True
+
+
+preload_jiter_native_extension()

tests/agent/test_jiter_preload.py

@@ -0,0 +1,25 @@
+from __future__ import annotations
+
+import importlib
+import sys
+
+from agent import jiter_preload
+
+
+def test_preload_jiter_native_extension_loads_sdk_parser_dependency():
+    assert jiter_preload.preload_jiter_native_extension() is True
+    assert "jiter.jiter" in sys.modules
+
+
+def test_preload_jiter_native_extension_is_best_effort(monkeypatch):
+    monkeypatch.setattr(jiter_preload, "_JITER_PRELOADED", False)
+
+    def _raise_missing(name: str):
+        assert name == "jiter.jiter"
+        raise ModuleNotFoundError(name)
+
+    monkeypatch.setattr(importlib, "import_module", _raise_missing)
+
+    assert jiter_preload.preload_jiter_native_extension() is False
+    assert jiter_preload._JITER_PRELOADED is False
+    assert isinstance(jiter_preload._JITER_PRELOAD_ERROR, ModuleNotFoundError)