refactor(rag): improve RAG manager implementation

- Introduce shared RAG manager singleton via get_rag_manager()
- Add DEFAULT_COLLECTION constant for consistent collection naming
- Remove unused _clear_cache function
- Update gptme-rag dependency to 0.3.1

gptme/tools/_rag_context.py

@@ -11,6 +11,9 @@
 
 logger = logging.getLogger(__name__)
 
+# Constant collection name to ensure consistency
+DEFAULT_COLLECTION = "gptme-default"
+
 try:
     import gptme_rag  # type: ignore # fmt: skip
 
@@ -20,10 +23,21 @@
     _HAS_RAG = False
 
 
+# Shared RAG manager instance
+_rag_manager: "RAGManager | None" = None
+
 # Simple in-memory cache for search results
 _search_cache: dict[str, tuple[list[Any], dict]] = {}
 
 
+def get_rag_manager() -> "RAGManager":
+    """Get or create the shared RAG manager instance."""
+    global _rag_manager
+    if _rag_manager is None:
+        _rag_manager = RAGManager()
+    return _rag_manager
+
+
 def _get_search_results(query: str, n_results: int) -> tuple[list[Any], dict] | None:
     """Get cached search results."""
     return _search_cache.get(f"{query}::{n_results}")
@@ -36,11 +50,6 @@ def _set_search_results(
     _search_cache[f"{query}::{n_results}"] = results
 
 
-def _clear_cache() -> None:
-    """Clear the search cache."""
-    _search_cache.clear()
-
-
 @dataclass
 class Context:
     """Context information to be added to messages."""
@@ -72,7 +81,7 @@ def __init__(self, index_path: Path | None = None, collection: str | None = None
 
         # Use config values if not overridden by parameters
         self.index_path = index_path or Path("~/.cache/gptme/rag").expanduser()
-        self.collection = collection or "default"
+        self.collection = collection or DEFAULT_COLLECTION
 
         # Initialize the indexer
         self.indexer = gptme_rag.Indexer(

gptme/tools/rag.py

@@ -50,13 +50,11 @@
 
 from ..config import get_project_config
 from ..util import get_project_dir
-from ._rag_context import _HAS_RAG, RAGManager
+from ._rag_context import _HAS_RAG, get_rag_manager
 from .base import ToolSpec, ToolUse
 
 logger = logging.getLogger(__name__)
 
-rag_manager: RAGManager | None = None
-
 instructions = """
 Use RAG to index and search project documentation.
 """
@@ -82,28 +80,28 @@
 
 def rag_index(*paths: str, glob: str | None = None) -> str:
     """Index documents in specified paths."""
-    assert rag_manager is not None, "RAG manager not initialized"
+    manager = get_rag_manager()
     paths = paths or (".",)
     kwargs = {"glob_pattern": glob} if glob else {}
     total_docs = 0
     for path in paths:
-        total_docs += rag_manager.index_directory(Path(path), **kwargs)
+        total_docs += manager.index_directory(Path(path), **kwargs)
     return f"Indexed {len(paths)} paths ({total_docs} documents)"
 
 
 def rag_search(query: str) -> str:
     """Search indexed documents."""
-    assert rag_manager is not None, "RAG manager not initialized"
-    docs, _ = rag_manager.search(query)
+    manager = get_rag_manager()
+    docs, _ = manager.search(query)
     return "\n\n".join(
         f"### {doc.metadata['source']}\n{doc.content[:200]}..." for doc in docs
     )
 
 
 def rag_status() -> str:
     """Show index status."""
-    assert rag_manager is not None, "RAG manager not initialized"
-    return f"Index contains {rag_manager.get_document_count()} documents"
+    manager = get_rag_manager()
+    return f"Index contains {manager.get_document_count()} documents"
 
 
 _init_run = False
@@ -129,8 +127,8 @@ def init() -> ToolSpec:
         logger.debug("Project configuration not found, not enabling")
         return replace(tool, available=False)
 
-    global rag_manager
-    rag_manager = RAGManager()
+    # Initialize the shared RAG manager
+    get_rag_manager()
     return tool
 
 

pyproject.toml

@@ -39,7 +39,7 @@ youtube_transcript_api = {version = "^0.6.1", optional = true}
 python-xlib = {version = "^0.33", optional = true}  # for X11 interaction
 
 # RAG
-gptme-rag = {version = "^0.3.0", optional = true}
+gptme-rag = {version = "^0.3.1", optional = true}
 #gptme-rag = {path = "../gptme-rag", optional = true, develop = true}
 
 # providers