Make mxbai reranker optional. Only use a reranker if mxbai or cohere are installed

docs/configuration.md

@@ -105,16 +105,20 @@ ANTHROPIC_API_KEY="your-api-key"
 
 ## Reranking
 
-Reranking is **enabled by default** and improves search quality by re-ordering the initial search results using specialized models. When enabled, the system retrieves more candidates (3x the requested limit) and then reranks them to return the most relevant results.
+Reranking improves search quality by re-ordering the initial search results using specialized models. When enabled, the system retrieves more candidates (3x the requested limit) and then reranks them to return the most relevant results.
 
-If you use the default reranked (running locally), it can slow down searching significantly. To disable reranking for faster searches:
-
-```bash
-RERANK=false
-```
+Reranking is **automatically enabled** if you install the appropriate reranking provider package.
 
 ### MixedBread AI (Default)
 
+For MxBAI reranking, install with mxbai extras:
+
+```bash
+uv pip install haiku.rag[mxbai]
+```
+
+Then configure:
+
 ```bash
 RERANK_PROVIDER="mxbai"
 RERANK_MODEL="mixedbread-ai/mxbai-rerank-base-v2"

pyproject.toml

@@ -25,7 +25,6 @@ dependencies = [
     "docling>=2.15.0",
     "fastmcp>=2.8.1",
     "httpx>=0.28.1",
-    "mxbai-rerank>=0.1.6",
     "ollama>=0.5.1",
     "pydantic>=2.11.7",
     "python-dotenv>=1.1.0",
@@ -41,6 +40,7 @@ voyageai = ["voyageai>=0.3.2"]
 openai = ["openai>=1.0.0"]
 anthropic = ["anthropic>=0.56.0"]
 cohere = ["cohere>=5.16.1"]
+mxbai = ["mxbai-rerank>=0.1.6"]
 
 [project.scripts]
 haiku-rag = "haiku.rag.cli:cli"

src/haiku/rag/client.py

@@ -319,7 +319,7 @@ class HaikuRAG:
         return await self.document_repository.list_all(limit=limit, offset=offset)
 
     async def search(
-        self, query: str, limit: int = 5, k: int = 60, rerank=Config.RERANK
+        self, query: str, limit: int = 5, k: int = 60
     ) -> list[tuple[Chunk, float]]:
         """Search for relevant chunks using hybrid search (vector similarity + full-text search) with reranking.
 
@@ -331,8 +331,10 @@ class HaikuRAG:
         Returns:
             List of (chunk, score) tuples ordered by relevance.
         """
+        # Get reranker if available
+        reranker = get_reranker()
 
-        if not rerank:
+        if reranker is None:
             return await self.chunk_repository.search_chunks_hybrid(query, limit, k)
 
         # Get more initial results (3X) for reranking
@@ -340,7 +342,6 @@ class HaikuRAG:
             query, limit * 3, k
         )
         # Apply reranking
-        reranker = get_reranker()
         chunks = [chunk for chunk, _ in search_results]
         reranked_results = await reranker.rerank(query, chunks, top_n=limit)
 

src/haiku/rag/config.py

@@ -19,7 +19,6 @@ class AppConfig(BaseModel):
     EMBEDDINGS_MODEL: str = "mxbai-embed-large"
     EMBEDDINGS_VECTOR_DIM: int = 1024
 
-    RERANK: bool = True
     RERANK_PROVIDER: str = "mxbai"
     RERANK_MODEL: str = "mixedbread-ai/mxbai-rerank-base-v2"
 

src/haiku/rag/reranking/__init__.py

@@ -9,29 +9,30 @@ except ImportError:
 _reranker: RerankerBase | None = None
 
 
-def get_reranker() -> RerankerBase:
+def get_reranker() -> RerankerBase | None:
     """
     Factory function to get the appropriate reranker based on the configuration.
+    Returns None if the required package is not available.
     """
     global _reranker
     if _reranker is not None:
         return _reranker
     if Config.RERANK_PROVIDER == "mxbai":
-        from haiku.rag.reranking.mxbai import MxBAIReranker
+        try:
+            from haiku.rag.reranking.mxbai import MxBAIReranker
 
-        _reranker = MxBAIReranker()
-        return _reranker
+            _reranker = MxBAIReranker()
+            return _reranker
+        except ImportError:
+            return None
 
     if Config.RERANK_PROVIDER == "cohere":
         try:
             from haiku.rag.reranking.cohere import CohereReranker
-        except ImportError:
-            raise ImportError(
-                "Cohere reranker requires the 'cohere' package. "
-                "Please install haiku.rag with the 'cohere' extra:"
-                "uv pip install haiku.rag[cohere]"
-            )
-        _reranker = CohereReranker()
-        return _reranker
 
-    raise ValueError(f"Unsupported reranker provider: {Config.RERANK_PROVIDER}")
+            _reranker = CohereReranker()
+            return _reranker
+        except ImportError:
+            return None
+
+    return None

tests/test_reranker.py

@@ -1,7 +1,6 @@
 import pytest
 
 from haiku.rag.reranking.base import RerankerBase
-from haiku.rag.reranking.mxbai import MxBAIReranker
 from haiku.rag.store.models.chunk import Chunk
 
 chunks = [
@@ -30,12 +29,17 @@ async def test_reranker_base():
 
 @pytest.mark.asyncio
 async def test_mxbai_reranker():
-    reranker = MxBAIReranker()
-    reranked = await reranker.rerank(
-        "Who wrote 'To Kill a Mockingbird'?", chunks, top_n=2
-    )
-    assert [chunk.document_id for chunk, score in reranked] == [0, 2]
-    assert all(isinstance(score, float) for chunk, score in reranked)
+    try:
+        from haiku.rag.reranking.mxbai import MxBAIReranker
+
+        reranker = MxBAIReranker()
+        reranked = await reranker.rerank(
+            "Who wrote 'To Kill a Mockingbird'?", chunks, top_n=2
+        )
+        assert [chunk.document_id for chunk, score in reranked] == [0, 2]
+        assert all(isinstance(score, float) for chunk, score in reranked)
+    except ImportError:
+        pytest.skip("MxBAI package not installed")
 
 
 @pytest.mark.asyncio

uv.lock

@@ -886,7 +886,6 @@ dependencies = [
     { name = "docling" },
     { name = "fastmcp" },
     { name = "httpx" },
-    { name = "mxbai-rerank" },
     { name = "ollama" },
     { name = "pydantic" },
     { name = "python-dotenv" },
@@ -904,6 +903,9 @@ anthropic = [
 cohere = [
     { name = "cohere" },
 ]
+mxbai = [
+    { name = "mxbai-rerank" },
+]
 openai = [
     { name = "openai" },
 ]
@@ -931,7 +933,7 @@ requires-dist = [
     { name = "docling", specifier = ">=2.15.0" },
     { name = "fastmcp", specifier = ">=2.8.1" },
     { name = "httpx", specifier = ">=0.28.1" },
-    { name = "mxbai-rerank", specifier = ">=0.1.6" },
+    { name = "mxbai-rerank", marker = "extra == 'mxbai'", specifier = ">=0.1.6" },
     { name = "ollama", specifier = ">=0.5.1" },
     { name = "openai", marker = "extra == 'openai'", specifier = ">=1.0.0" },
     { name = "pydantic", specifier = ">=2.11.7" },
@@ -943,7 +945,7 @@ requires-dist = [
     { name = "voyageai", marker = "extra == 'voyageai'", specifier = ">=0.3.2" },
     { name = "watchfiles", specifier = ">=1.1.0" },
 ]
-provides-extras = ["voyageai", "openai", "anthropic", "cohere"]
+provides-extras = ["voyageai", "openai", "anthropic", "cohere", "mxbai"]
 
 [package.metadata.requires-dev]
 dev = [