fixing chunking token issues within limit for embedding models

* feat: add metadata output to search results

- Add --show-metadata flag to display file paths in search results
- Preserve document metadata (file_path, file_name, timestamps) during chunking
- Update MCP tool schema to support show_metadata parameter
- Enhance CLI search output to display metadata when requested
- Fix pre-existing bug: args.backend -> args.backend_name

Resolves yichuan-w/LEANN#144

* fix: resolve ZMQ linking issues in Python extension

- Use pkg_check_modules IMPORTED_TARGET to create PkgConfig::ZMQ
- Set PKG_CONFIG_PATH to prioritize ARM64 Homebrew on Apple Silicon
- Override macOS -undefined dynamic_lookup to force proper symbol resolution
- Use PUBLIC linkage for ZMQ in faiss library for transitive linking
- Mark cppzmq includes as SYSTEM to suppress warnings

Fixes editable install ZMQ symbol errors while maintaining compatibility
across Linux, macOS Intel, and macOS ARM64 platforms.

* style: apply ruff formatting

* chore: update faiss submodule to use ww2283 fork

Use ww2283/faiss fork with fix/zmq-linking branch to resolve CI checkout
failures. The ZMQ linking fixes are not yet merged upstream.

* feat: implement true batch processing for Ollama embeddings

Migrate from deprecated /api/embeddings to modern /api/embed endpoint
which supports batch inputs. This reduces HTTP overhead by sending
32 texts per request instead of making individual API calls.

Changes:
- Update endpoint from /api/embeddings to /api/embed
- Change parameter from 'prompt' (single) to 'input' (array)
- Update response parsing for batch embeddings array
- Increase timeout to 60s for batch processing
- Improve error handling for batch requests

Performance:
- Reduces API calls by 32x (batch size)
- Eliminates HTTP connection overhead per text
- Note: Ollama still processes batch items sequentially internally

Related: #151

* fall back to original faiss as i merge the PR

---------

Co-authored-by: yichuan520030910320 <yichuan_wang@berkeley.edu>

.gitignore

@@ -105,3 +105,6 @@ apps/multimodal/vision-based-pdf-multi-vector/multi-vector-colpali-native-weavia
 # The following line used to force-add a large demo PDF; remove it to satisfy pre-commit:
 # !apps/multimodal/vision-based-pdf-multi-vector/pdfs/2004.12832v2.pdf
 !apps/multimodal/vision-based-pdf-multi-vector/fig/*
+
+# AUR build directory (Arch Linux)
+paru-bin/

README.md

@@ -1213,3 +1213,7 @@ This work is done at [**Berkeley Sky Computing Lab**](https://sky.cs.berkeley.ed
 <p align="center">
   Made with ❤️ by the Leann team
 </p>
+
+## 🤖 Explore LEANN with AI
+
+LEANN is indexed on [DeepWiki](https://deepwiki.com/yichuan-w/LEANN), so you can ask questions to LLMs using Deep Research to explore the codebase and get help to add new features.

apps/base_rag_example.py

@@ -180,14 +180,14 @@ class BaseRAGExample(ABC):
         ast_group.add_argument(
             "--ast-chunk-size",
             type=int,
-            default=512,
+            default=300,
-            help="Maximum characters per AST chunk (default: 512)",
+            help="Maximum CHARACTERS per AST chunk (default: 300). Final chunks may be larger due to overlap. For 512 token models: recommended 300 chars",
         )
         ast_group.add_argument(
             "--ast-chunk-overlap",
             type=int,
             default=64,
-            help="Overlap between AST chunks (default: 64)",
+            help="Overlap between AST chunks in CHARACTERS (default: 64). Added to chunk size, not included in it",
         )
         ast_group.add_argument(
             "--code-file-extensions",

packages/leann-backend-hnsw/CMakeLists.txt

@@ -29,12 +29,25 @@ if(APPLE)
     set(CMAKE_OSX_DEPLOYMENT_TARGET "11.0" CACHE STRING "Minimum macOS version")
 endif()
 
-# Use system ZeroMQ instead of building from source
+# Find ZMQ using pkg-config with IMPORTED_TARGET for automatic target creation
 find_package(PkgConfig REQUIRED)
-pkg_check_modules(ZMQ REQUIRED libzmq)
+
+# On ARM64 macOS, ensure pkg-config finds ARM64 Homebrew packages first
+if(APPLE AND CMAKE_SYSTEM_PROCESSOR MATCHES "aarch64|arm64")
+    set(ENV{PKG_CONFIG_PATH} "/opt/homebrew/lib/pkgconfig:/opt/homebrew/share/pkgconfig:$ENV{PKG_CONFIG_PATH}")
+endif()
+
+pkg_check_modules(ZMQ REQUIRED IMPORTED_TARGET libzmq)
+
+# This creates PkgConfig::ZMQ target automatically with correct properties
+if(TARGET PkgConfig::ZMQ)
+    message(STATUS "Found and configured ZMQ target: PkgConfig::ZMQ")
+else()
+    message(FATAL_ERROR "pkg_check_modules did not create IMPORTED target for ZMQ.")
+endif()
 
 # Add cppzmq headers
-include_directories(third_party/cppzmq)
+include_directories(SYSTEM third_party/cppzmq)
 
 # Configure msgpack-c - disable boost dependency
 set(MSGPACK_USE_BOOST OFF CACHE BOOL "" FORCE)

packages/leann-core/src/leann/chunking_utils.py

@@ -11,6 +11,119 @@ from llama_index.core.node_parser import SentenceSplitter
 
 logger = logging.getLogger(__name__)
 
+
+def estimate_token_count(text: str) -> int:
+    """
+    Estimate token count for a text string.
+    Uses conservative estimation: ~4 characters per token for natural text,
+    ~1.2 tokens per character for code (worse tokenization).
+
+    Args:
+        text: Input text to estimate tokens for
+
+    Returns:
+        Estimated token count
+    """
+    try:
+        import tiktoken
+
+        encoder = tiktoken.get_encoding("cl100k_base")
+        return len(encoder.encode(text))
+    except ImportError:
+        # Fallback: Conservative character-based estimation
+        # Assume worst case for code: 1.2 tokens per character
+        return int(len(text) * 1.2)
+
+
+def calculate_safe_chunk_size(
+    model_token_limit: int,
+    overlap_tokens: int,
+    chunking_mode: str = "traditional",
+    safety_factor: float = 0.9,
+) -> int:
+    """
+    Calculate safe chunk size accounting for overlap and safety margin.
+
+    Args:
+        model_token_limit: Maximum tokens supported by embedding model
+        overlap_tokens: Overlap size (tokens for traditional, chars for AST)
+        chunking_mode: "traditional" (tokens) or "ast" (characters)
+        safety_factor: Safety margin (0.9 = 10% safety margin)
+
+    Returns:
+        Safe chunk size: tokens for traditional, characters for AST
+    """
+    safe_limit = int(model_token_limit * safety_factor)
+
+    if chunking_mode == "traditional":
+        # Traditional chunking uses tokens
+        # Max chunk = chunk_size + overlap, so chunk_size = limit - overlap
+        return max(1, safe_limit - overlap_tokens)
+    else:  # AST chunking
+        # AST uses characters, need to convert
+        # Conservative estimate: 1.2 tokens per char for code
+        overlap_chars = int(overlap_tokens * 3)  # ~3 chars per token for code
+        safe_chars = int(safe_limit / 1.2)
+        return max(1, safe_chars - overlap_chars)
+
+
+def validate_chunk_token_limits(chunks: list[str], max_tokens: int = 512) -> tuple[list[str], int]:
+    """
+    Validate that chunks don't exceed token limits and truncate if necessary.
+
+    Args:
+        chunks: List of text chunks to validate
+        max_tokens: Maximum tokens allowed per chunk
+
+    Returns:
+        Tuple of (validated_chunks, num_truncated)
+    """
+    validated_chunks = []
+    num_truncated = 0
+
+    for i, chunk in enumerate(chunks):
+        estimated_tokens = estimate_token_count(chunk)
+
+        if estimated_tokens > max_tokens:
+            # Truncate chunk to fit token limit
+            try:
+                import tiktoken
+
+                encoder = tiktoken.get_encoding("cl100k_base")
+                tokens = encoder.encode(chunk)
+                if len(tokens) > max_tokens:
+                    truncated_tokens = tokens[:max_tokens]
+                    truncated_chunk = encoder.decode(truncated_tokens)
+                    validated_chunks.append(truncated_chunk)
+                    num_truncated += 1
+                    logger.warning(
+                        f"Truncated chunk {i} from {len(tokens)} to {max_tokens} tokens "
+                        f"(from {len(chunk)} to {len(truncated_chunk)} characters)"
+                    )
+                else:
+                    validated_chunks.append(chunk)
+            except ImportError:
+                # Fallback: Conservative character truncation
+                char_limit = int(max_tokens / 1.2)  # Conservative for code
+                if len(chunk) > char_limit:
+                    truncated_chunk = chunk[:char_limit]
+                    validated_chunks.append(truncated_chunk)
+                    num_truncated += 1
+                    logger.warning(
+                        f"Truncated chunk {i} from {len(chunk)} to {char_limit} characters "
+                        f"(conservative estimate for {max_tokens} tokens)"
+                    )
+                else:
+                    validated_chunks.append(chunk)
+        else:
+            validated_chunks.append(chunk)
+
+    if num_truncated > 0:
+        logger.warning(f"Truncated {num_truncated}/{len(chunks)} chunks to fit token limits")
+
+    return validated_chunks, num_truncated
+
+
 # Code file extensions supported by astchunk
 CODE_EXTENSIONS = {
     ".py": "python",
@@ -82,6 +195,17 @@ def create_ast_chunks(
             continue
 
         try:
+            # Warn if AST chunk size + overlap might exceed common token limits
+            estimated_max_tokens = int(
+                (max_chunk_size + chunk_overlap) * 1.2
+            )  # Conservative estimate
+            if estimated_max_tokens > 512:
+                logger.warning(
+                    f"AST chunk size ({max_chunk_size}) + overlap ({chunk_overlap}) = {max_chunk_size + chunk_overlap} chars "
+                    f"may exceed 512 token limit (~{estimated_max_tokens} tokens estimated). "
+                    f"Consider reducing --ast-chunk-size to {int(400 / 1.2)} or --ast-chunk-overlap to {int(50 / 1.2)}"
+                )
+
             configs = {
                 "max_chunk_size": max_chunk_size,
                 "language": language,
@@ -217,4 +341,14 @@ def create_text_chunks(
         all_chunks = create_traditional_chunks(documents, chunk_size, chunk_overlap)
 
     logger.info(f"Total chunks created: {len(all_chunks)}")
-    return all_chunks
+
+    # Validate chunk token limits (default to 512 for safety)
+    # This provides a safety net for embedding models with token limits
+    validated_chunks, num_truncated = validate_chunk_token_limits(all_chunks, max_tokens=512)
+
+    if num_truncated > 0:
+        logger.info(
+            f"Post-chunking validation: {num_truncated} chunks were truncated to fit 512 token limit"
+        )
+
+    return validated_chunks

packages/leann-core/src/leann/cli.py

@@ -181,25 +181,25 @@ Examples:
             "--doc-chunk-size",
             type=int,
             default=256,
-            help="Document chunk size in tokens/characters (default: 256)",
+            help="Document chunk size in TOKENS (default: 256). Final chunks may be larger due to overlap. For 512 token models: recommended 350 tokens (350 + 128 overlap = 478 max)",
         )
         build_parser.add_argument(
             "--doc-chunk-overlap",
             type=int,
             default=128,
-            help="Document chunk overlap (default: 128)",
+            help="Document chunk overlap in TOKENS (default: 128). Added to chunk size, not included in it",
         )
         build_parser.add_argument(
             "--code-chunk-size",
             type=int,
             default=512,
-            help="Code chunk size in tokens/lines (default: 512)",
+            help="Code chunk size in TOKENS (default: 512). Final chunks may be larger due to overlap. For 512 token models: recommended 400 tokens (400 + 50 overlap = 450 max)",
         )
         build_parser.add_argument(
             "--code-chunk-overlap",
             type=int,
             default=50,
-            help="Code chunk overlap (default: 50)",
+            help="Code chunk overlap in TOKENS (default: 50). Added to chunk size, not included in it",
         )
         build_parser.add_argument(
             "--use-ast-chunking",
@@ -209,14 +209,14 @@ Examples:
         build_parser.add_argument(
             "--ast-chunk-size",
             type=int,
-            default=768,
+            default=300,
-            help="AST chunk size in characters (default: 768)",
+            help="AST chunk size in CHARACTERS (non-whitespace) (default: 300). Final chunks may be larger due to overlap and expansion. For 512 token models: recommended 300 chars (300 + 64 overlap ~= 480 tokens)",
         )
         build_parser.add_argument(
             "--ast-chunk-overlap",
             type=int,
-            default=96,
+            default=64,
-            help="AST chunk overlap in characters (default: 96)",
+            help="AST chunk overlap in CHARACTERS (default: 64). Added to chunk size, not included in it. ~1.2 tokens per character for code",
         )
         build_parser.add_argument(
             "--ast-fallback-traditional",
@@ -255,6 +255,11 @@ Examples:
             action="store_true",
             help="Non-interactive mode: automatically select index without prompting",
         )
+        search_parser.add_argument(
+            "--show-metadata",
+            action="store_true",
+            help="Display file paths and metadata in search results",
+        )
 
         # Ask command
         ask_parser = subparsers.add_parser("ask", help="Ask questions")
@@ -1263,7 +1268,7 @@ Examples:
                 from .chunking_utils import create_text_chunks
 
                 # Use enhanced chunking with AST support
-                all_texts = create_text_chunks(
+                chunk_texts = create_text_chunks(
                     documents,
                     chunk_size=self.node_parser.chunk_size,
                     chunk_overlap=self.node_parser.chunk_overlap,
@@ -1274,6 +1279,14 @@ Examples:
                     ast_fallback_traditional=getattr(args, "ast_fallback_traditional", True),
                 )
 
+                # Note: AST chunking currently returns plain text chunks without metadata
+                # We preserve basic file info by associating chunks with their source documents
+                # For better metadata preservation, documents list order should be maintained
+                for chunk_text in chunk_texts:
+                    # TODO: Enhance create_text_chunks to return metadata alongside text
+                    # For now, we store chunks with empty metadata
+                    all_texts.append({"text": chunk_text, "metadata": {}})
+
             except ImportError as e:
                 print(
                     f"⚠️  AST chunking utilities not available in package ({e}), falling back to traditional chunking"
@@ -1285,17 +1298,27 @@ Examples:
             for doc in tqdm(documents, desc="Chunking documents", unit="doc"):
                 # Check if this is a code file based on source path
                 source_path = doc.metadata.get("source", "")
+                file_path = doc.metadata.get("file_path", "")
                 is_code_file = any(source_path.endswith(ext) for ext in code_file_exts)
 
+                # Extract metadata to preserve with chunks
+                chunk_metadata = {
+                    "file_path": file_path or source_path,
+                    "file_name": doc.metadata.get("file_name", ""),
+                }
+
+                # Add optional metadata if available
+                if "creation_date" in doc.metadata:
+                    chunk_metadata["creation_date"] = doc.metadata["creation_date"]
+                if "last_modified_date" in doc.metadata:
+                    chunk_metadata["last_modified_date"] = doc.metadata["last_modified_date"]
+
                 # Use appropriate parser based on file type
                 parser = self.code_parser if is_code_file else self.node_parser
                 nodes = parser.get_nodes_from_documents([doc])
 
                 for node in nodes:
-                    text_with_source = (
+                    all_texts.append({"text": node.get_content(), "metadata": chunk_metadata})
-                        "Chunk source:" + source_path + "\n" + node.get_content().replace("\n", " ")
-                    )
-                    all_texts.append(text_with_source)
 
         print(f"Loaded {len(documents)} documents, {len(all_texts)} chunks")
         return all_texts
@@ -1370,7 +1393,7 @@ Examples:
 
         index_dir.mkdir(parents=True, exist_ok=True)
 
-        print(f"Building index '{index_name}' with {args.backend} backend...")
+        print(f"Building index '{index_name}' with {args.backend_name} backend...")
 
         embedding_options: dict[str, Any] = {}
         if args.embedding_mode == "ollama":
@@ -1382,7 +1405,7 @@ Examples:
                 embedding_options["api_key"] = resolved_embedding_key
 
         builder = LeannBuilder(
-            backend_name=args.backend,
+            backend_name=args.backend_name,
             embedding_model=args.embedding_model,
             embedding_mode=args.embedding_mode,
             embedding_options=embedding_options or None,
@@ -1393,10 +1416,8 @@ Examples:
             num_threads=args.num_threads,
         )
 
-        for chunk_text_with_source in all_texts:
+        for chunk in all_texts:
-            chunk_source = chunk_text_with_source.split("\n")[0].split(":")[1]
+            builder.add_text(chunk["text"], metadata=chunk["metadata"])
-            chunk_text = chunk_text_with_source.split("\n")[1]
-            builder.add_text(chunk_text, {"source": chunk_source})
 
         builder.build_index(index_path)
         print(f"Index built at {index_path}")
@@ -1517,6 +1538,23 @@ Examples:
         print(f"Search results for '{query}' (top {len(results)}):")
         for i, result in enumerate(results, 1):
             print(f"{i}. Score: {result.score:.3f}")
+
+            # Display metadata if flag is set
+            if args.show_metadata and result.metadata:
+                file_path = result.metadata.get("file_path", "")
+                if file_path:
+                    print(f"   📄 File: {file_path}")
+
+                file_name = result.metadata.get("file_name", "")
+                if file_name and file_name != file_path:
+                    print(f"   📝 Name: {file_name}")
+
+                # Show timestamps if available
+                if "creation_date" in result.metadata:
+                    print(f"   🕐 Created: {result.metadata['creation_date']}")
+                if "last_modified_date" in result.metadata:
+                    print(f"   🕑 Modified: {result.metadata['last_modified_date']}")
+
             print(f"   {result.text[:200]}...")
             print(f"   Source: {result.metadata.get('source', '')}")
             print()

packages/leann-core/src/leann/embedding_compute.py

@@ -14,6 +14,89 @@ import torch
 
 from .settings import resolve_ollama_host, resolve_openai_api_key, resolve_openai_base_url
 
+
+def truncate_to_token_limit(texts: list[str], max_tokens: int = 512) -> list[str]:
+    """
+    Truncate texts to token limit using tiktoken or conservative character truncation.
+
+    Args:
+        texts: List of texts to truncate
+        max_tokens: Maximum tokens allowed per text
+
+    Returns:
+        List of truncated texts that should fit within token limit
+    """
+    try:
+        import tiktoken
+
+        encoder = tiktoken.get_encoding("cl100k_base")
+        truncated = []
+
+        for text in texts:
+            tokens = encoder.encode(text)
+            if len(tokens) > max_tokens:
+                # Truncate to max_tokens and decode back to text
+                truncated_tokens = tokens[:max_tokens]
+                truncated_text = encoder.decode(truncated_tokens)
+                truncated.append(truncated_text)
+                logger.warning(
+                    f"Truncated text from {len(tokens)} to {max_tokens} tokens "
+                    f"(from {len(text)} to {len(truncated_text)} characters)"
+                )
+            else:
+                truncated.append(text)
+        return truncated
+
+    except ImportError:
+        # Fallback: Conservative character truncation
+        # Assume worst case: 1.5 tokens per character for code content
+        char_limit = int(max_tokens / 1.5)
+        truncated = []
+
+        for text in texts:
+            if len(text) > char_limit:
+                truncated_text = text[:char_limit]
+                truncated.append(truncated_text)
+                logger.warning(
+                    f"Truncated text from {len(text)} to {char_limit} characters "
+                    f"(conservative estimate for {max_tokens} tokens)"
+                )
+            else:
+                truncated.append(text)
+        return truncated
+
+
+def get_model_token_limit(model_name: str) -> int:
+    """
+    Get token limit for a given embedding model.
+
+    Args:
+        model_name: Name of the embedding model
+
+    Returns:
+        Token limit for the model, defaults to 512 if unknown
+    """
+    # Handle versioned model names (e.g., "nomic-embed-text:latest" -> "nomic-embed-text")
+    base_model_name = model_name.split(":")[0]
+
+    # Check exact match first
+    if model_name in EMBEDDING_MODEL_LIMITS:
+        return EMBEDDING_MODEL_LIMITS[model_name]
+
+    # Check base name match
+    if base_model_name in EMBEDDING_MODEL_LIMITS:
+        return EMBEDDING_MODEL_LIMITS[base_model_name]
+
+    # Check partial matches for common patterns
+    for known_model, limit in EMBEDDING_MODEL_LIMITS.items():
+        if known_model in base_model_name or base_model_name in known_model:
+            return limit
+
+    # Default to conservative 512 token limit
+    logger.warning(f"Unknown model '{model_name}', using default 512 token limit")
+    return 512
+
+
 # Set up logger with proper level
 logger = logging.getLogger(__name__)
 LOG_LEVEL = os.getenv("LEANN_LOG_LEVEL", "WARNING").upper()
@@ -23,6 +106,17 @@ logger.setLevel(log_level)
 # Global model cache to avoid repeated loading
 _model_cache: dict[str, Any] = {}
 
+# Known embedding model token limits
+EMBEDDING_MODEL_LIMITS = {
+    "nomic-embed-text": 512,
+    "nomic-embed-text-v2": 512,
+    "mxbai-embed-large": 512,
+    "all-minilm": 512,
+    "bge-m3": 8192,
+    "snowflake-arctic-embed": 512,
+    # Add more models as needed
+}
+
 
 def compute_embeddings(
     texts: list[str],
@@ -574,9 +668,10 @@ def compute_embeddings_ollama(
     host: Optional[str] = None,
 ) -> np.ndarray:
     """
-    Compute embeddings using Ollama API with simplified batch processing.
+    Compute embeddings using Ollama API with true batch processing.
 
-    Uses batch size of 32 for MPS/CPU and 128 for CUDA to optimize performance.
+    Uses the /api/embed endpoint which supports batch inputs.
+    Batch size: 32 for MPS/CPU, 128 for CUDA to optimize performance.
 
     Args:
         texts: List of texts to compute embeddings for
@@ -681,11 +776,11 @@ def compute_embeddings_ollama(
             logger.info(f"Resolved model name '{model_name}' to '{resolved_model_name}'")
         model_name = resolved_model_name
 
-        # Verify the model supports embeddings by testing it
+        # Verify the model supports embeddings by testing it with /api/embed
         try:
             test_response = requests.post(
-                f"{resolved_host}/api/embeddings",
+                f"{resolved_host}/api/embed",
-                json={"model": model_name, "prompt": "test"},
+                json={"model": model_name, "input": "test"},
                 timeout=10,
             )
             if test_response.status_code != 200:
@@ -717,63 +812,80 @@ def compute_embeddings_ollama(
         # If torch is not available, use conservative batch size
         batch_size = 32
 
-    logger.info(f"Using batch size: {batch_size}")
+    logger.info(f"Using batch size: {batch_size} for true batch processing")
+
+    # Get model token limit and apply truncation
+    token_limit = get_model_token_limit(model_name)
+    logger.info(f"Model '{model_name}' token limit: {token_limit}")
+
+    # Apply token-aware truncation to all texts
+    truncated_texts = truncate_to_token_limit(texts, token_limit)
+    if len(truncated_texts) != len(texts):
+        logger.error("Truncation failed - text count mismatch")
+        truncated_texts = texts  # Fallback to original texts
 
     def get_batch_embeddings(batch_texts):
-        """Get embeddings for a batch of texts."""
+        """Get embeddings for a batch of texts using /api/embed endpoint."""
-        all_embeddings = []
+        max_retries = 3
-        failed_indices = []
+        retry_count = 0
 
-        for i, text in enumerate(batch_texts):
+        # Texts are already truncated to token limit by the outer function
-            max_retries = 3
+        while retry_count < max_retries:
-            retry_count = 0
+            try:
+                # Use /api/embed endpoint with "input" parameter for batch processing
+                response = requests.post(
+                    f"{resolved_host}/api/embed",
+                    json={"model": model_name, "input": batch_texts},
+                    timeout=60,  # Increased timeout for batch processing
+                )
+                response.raise_for_status()
 
-            # Truncate very long texts to avoid API issues
+                result = response.json()
-            truncated_text = text[:8000] if len(text) > 8000 else text
+                batch_embeddings = result.get("embeddings")
-            while retry_count < max_retries:
+
-                try:
+                if batch_embeddings is None:
-                    response = requests.post(
+                    raise ValueError("No embeddings returned from API")
-                        f"{resolved_host}/api/embeddings",
+
-                        json={"model": model_name, "prompt": truncated_text},
+                if not isinstance(batch_embeddings, list):
-                        timeout=30,
+                    raise ValueError(f"Invalid embeddings format: {type(batch_embeddings)}")
+
+                if len(batch_embeddings) != len(batch_texts):
+                    raise ValueError(
+                        f"Mismatch: requested {len(batch_texts)} embeddings, got {len(batch_embeddings)}"
                     )
-                    response.raise_for_status()
 
-                    result = response.json()
+                return batch_embeddings, []
-                    embedding = result.get("embedding")
 
-                    if embedding is None:
+            except requests.exceptions.Timeout:
-                        raise ValueError(f"No embedding returned for text {i}")
+                retry_count += 1
+                if retry_count >= max_retries:
+                    logger.warning(f"Timeout for batch after {max_retries} retries")
+                    return None, list(range(len(batch_texts)))
 
-                    if not isinstance(embedding, list) or len(embedding) == 0:
+            except Exception as e:
-                        raise ValueError(f"Invalid embedding format for text {i}")
+                retry_count += 1
+                if retry_count >= max_retries:
+                    # Enhanced error detection for token limit violations
+                    error_msg = str(e).lower()
+                    if "token" in error_msg and (
+                        "limit" in error_msg or "exceed" in error_msg or "length" in error_msg
+                    ):
+                        logger.error(
+                            f"Token limit exceeded for batch. Error: {e}. "
+                            f"Consider reducing chunk sizes or check token truncation."
+                        )
+                    else:
+                        logger.error(f"Failed to get embeddings for batch: {e}")
+                    return None, list(range(len(batch_texts)))
 
-                    all_embeddings.append(embedding)
+        return None, list(range(len(batch_texts)))
-                    break
 
-                except requests.exceptions.Timeout:
+    # Process truncated texts in batches
-                    retry_count += 1
-                    if retry_count >= max_retries:
-                        logger.warning(f"Timeout for text {i} after {max_retries} retries")
-                        failed_indices.append(i)
-                        all_embeddings.append(None)
-                        break
-
-                except Exception as e:
-                    retry_count += 1
-                    if retry_count >= max_retries:
-                        logger.error(f"Failed to get embedding for text {i}: {e}")
-                        failed_indices.append(i)
-                        all_embeddings.append(None)
-                        break
-        return all_embeddings, failed_indices
-
-    # Process texts in batches
     all_embeddings = []
     all_failed_indices = []
 
     # Setup progress bar if needed
-    show_progress = is_build or len(texts) > 10
+    show_progress = is_build or len(truncated_texts) > 10
     try:
         if show_progress:
             from tqdm import tqdm
@@ -781,32 +893,36 @@ def compute_embeddings_ollama(
         show_progress = False
 
     # Process batches
-    num_batches = (len(texts) + batch_size - 1) // batch_size
+    num_batches = (len(truncated_texts) + batch_size - 1) // batch_size
 
     if show_progress:
-        batch_iterator = tqdm(range(num_batches), desc="Computing Ollama embeddings")
+        batch_iterator = tqdm(range(num_batches), desc="Computing Ollama embeddings (batched)")
     else:
         batch_iterator = range(num_batches)
 
     for batch_idx in batch_iterator:
         start_idx = batch_idx * batch_size
-        end_idx = min(start_idx + batch_size, len(texts))
+        end_idx = min(start_idx + batch_size, len(truncated_texts))
-        batch_texts = texts[start_idx:end_idx]
+        batch_texts = truncated_texts[start_idx:end_idx]
 
         batch_embeddings, batch_failed = get_batch_embeddings(batch_texts)
 
-        # Adjust failed indices to global indices
+        if batch_embeddings is not None:
-        global_failed = [start_idx + idx for idx in batch_failed]
+            all_embeddings.extend(batch_embeddings)
-        all_failed_indices.extend(global_failed)
+        else:
-        all_embeddings.extend(batch_embeddings)
+            # Entire batch failed, add None placeholders
+            all_embeddings.extend([None] * len(batch_texts))
+            # Adjust failed indices to global indices
+            global_failed = [start_idx + idx for idx in batch_failed]
+            all_failed_indices.extend(global_failed)
 
     # Handle failed embeddings
     if all_failed_indices:
-        if len(all_failed_indices) == len(texts):
+        if len(all_failed_indices) == len(truncated_texts):
             raise RuntimeError("Failed to compute any embeddings")
 
         logger.warning(
-            f"Failed to compute embeddings for {len(all_failed_indices)}/{len(texts)} texts"
+            f"Failed to compute embeddings for {len(all_failed_indices)}/{len(truncated_texts)} texts"
         )
 
         # Use zero embeddings as fallback for failed ones

packages/leann-core/src/leann/mcp.py

@@ -60,6 +60,11 @@ def handle_request(request):
                                     "maximum": 128,
                                     "description": "Search complexity level. Use 16-32 for fast searches (recommended), 64+ for higher precision when needed.",
                                 },
+                                "show_metadata": {
+                                    "type": "boolean",
+                                    "default": False,
+                                    "description": "Include file paths and metadata in search results. Useful for understanding which files contain the results.",
+                                },
                             },
                             "required": ["index_name", "query"],
                         },
@@ -104,6 +109,8 @@ def handle_request(request):
                     f"--complexity={args.get('complexity', 32)}",
                     "--non-interactive",
                 ]
+                if args.get("show_metadata", False):
+                    cmd.append("--show-metadata")
                 result = subprocess.run(cmd, capture_output=True, text=True)
 
             elif tool_name == "leann_list":