From d08360ca214cbcf473642900ab2175b49e31ed6a Mon Sep 17 00:00:00 2001
From: Jon Saad-Falcon <41205309+jonsaadfalcon@users.noreply.github.com>
Date: Wed, 25 Mar 2026 13:15:06 -0700
Subject: [PATCH] feat: wire gemma_cpp engine into discovery and optional
 imports

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/openjarvis/engine/__init__.py   |  2 +-
 src/openjarvis/engine/_discovery.py | 12 ++++++++++
 tests/engine/test_gemma_cpp.py      | 34 +++++++++++++++++++++++++++++
 3 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/src/openjarvis/engine/__init__.py b/src/openjarvis/engine/__init__.py
index b6f79eae..90486fe6 100644
--- a/src/openjarvis/engine/__init__.py
+++ b/src/openjarvis/engine/__init__.py
@@ -15,7 +15,7 @@ from openjarvis.engine._base import (
 from openjarvis.engine._discovery import discover_engines, discover_models, get_engine
 
 # Optional engines — only register if their SDK deps are present
-for _optional in ("cloud", "litellm"):
+for _optional in ("cloud", "litellm", "gemma_cpp"):
     try:
         importlib.import_module(f".{_optional}", __name__)
     except ImportError:
diff --git a/src/openjarvis/engine/_discovery.py b/src/openjarvis/engine/_discovery.py
index 4e2fc695..83021858 100644
--- a/src/openjarvis/engine/_discovery.py
+++ b/src/openjarvis/engine/_discovery.py
@@ -25,12 +25,24 @@ _HOST_MAP: Dict[str, str | None] = {
     "apple_fm": "apple_fm_host",
     "cloud": None,
     "litellm": None,
+    "gemma_cpp": None,
 }
 
 
 def _make_engine(key: str, config: JarvisConfig) -> InferenceEngine:
     """Instantiate a registered engine with the appropriate config host."""
     cls = EngineRegistry.get(key)
+
+    # gemma_cpp: pass config fields instead of host
+    if key == "gemma_cpp":
+        cfg = config.engine.gemma_cpp
+        return cls(
+            model_path=cfg.model_path or None,
+            tokenizer_path=cfg.tokenizer_path or None,
+            model_type=cfg.model_type or None,
+            num_threads=cfg.num_threads,
+        )
+
     host_attr = _HOST_MAP.get(key)
     if host_attr is not None:
         host = getattr(config.engine, host_attr, None)
diff --git a/tests/engine/test_gemma_cpp.py b/tests/engine/test_gemma_cpp.py
index f7dffe22..34d7e7d6 100644
--- a/tests/engine/test_gemma_cpp.py
+++ b/tests/engine/test_gemma_cpp.py
@@ -323,3 +323,37 @@ class TestGemmaCppConfigResolution:
         assert engine._tokenizer_path == ""
         assert engine._model_type == ""
         assert engine._num_threads == 0
+
+
+class TestGemmaCppDiscovery:
+    def test_host_map_contains_gemma_cpp(self) -> None:
+        from openjarvis.engine._discovery import _HOST_MAP
+        assert "gemma_cpp" in _HOST_MAP
+        assert _HOST_MAP["gemma_cpp"] is None
+
+    def test_make_engine_passes_config(self) -> None:
+        from openjarvis.core.config import GemmaCppEngineConfig, JarvisConfig
+        from openjarvis.core.registry import EngineRegistry
+        from openjarvis.engine._discovery import _make_engine
+        from openjarvis.engine.gemma_cpp import GemmaCppEngine
+
+        EngineRegistry.register_value("gemma_cpp", GemmaCppEngine)
+        config = JarvisConfig()
+        config.engine.gemma_cpp = GemmaCppEngineConfig(
+            model_path="/cfg/model.sbs",
+            tokenizer_path="/cfg/tokenizer.spm",
+            model_type="9b-it",
+            num_threads=4,
+        )
+        engine = _make_engine("gemma_cpp", config)
+        assert engine._model_path == "/cfg/model.sbs"
+        assert engine._tokenizer_path == "/cfg/tokenizer.spm"
+        assert engine._model_type == "9b-it"
+        assert engine._num_threads == 4
+
+    def test_registry_contains_gemma_cpp(self) -> None:
+        from openjarvis.core.registry import EngineRegistry
+        from openjarvis.engine.gemma_cpp import GemmaCppEngine
+
+        EngineRegistry.register_value("gemma_cpp", GemmaCppEngine)
+        assert EngineRegistry.contains("gemma_cpp")