diff --git a/.gitignore b/.gitignore
index fbd80f2..8ae7494 100755
--- a/.gitignore
+++ b/.gitignore
@@ -101,3 +101,4 @@ CLAUDE.local.md
 .claude/*.local.*
 .claude/local/*
 benchmarks/data/
+test_add/*
diff --git a/examples/dynamic_add_leann_no_recompute.py b/examples/dynamic_add_leann_no_recompute.py
new file mode 100644
index 0000000..27c6bb1
--- /dev/null
+++ b/examples/dynamic_add_leann_no_recompute.py
@@ -0,0 +1,410 @@
+"""
+Dynamic add example for LEANN using HNSW backend without recompute.
+
+- Builds a base index from a directory of documents
+- Incrementally adds new documents without recomputing stored embeddings
+
+Defaults:
+- Base data: /Users/yichuan/Desktop/code/LEANN/leann/data
+- Incremental data: /Users/yichuan/Desktop/code/LEANN/leann/test_add
+- Index path: <index_dir>/documents.leann
+
+Usage examples:
+  uv run python examples/dynamic_add_leann_no_recompute.py --build-base \
+    --base-dir /Users/yichuan/Desktop/code/LEANN/leann/data \
+    --index-dir ./test_doc_files
+
+  uv run python examples/dynamic_add_leann_no_recompute.py --add-incremental \
+    --add-dir /Users/yichuan/Desktop/code/LEANN/leann/test_add \
+    --index-dir ./test_doc_files
+"""
+
+import argparse
+import json
+import pickle
+import sys
+from pathlib import Path
+from typing import Any, Optional
+
+# Ensure we can import from the local packages and apps folders
+ROOT = Path(__file__).resolve().parents[1]
+CORE_SRC = ROOT / "packages" / "leann-core" / "src"
+HNSW_PKG_DIR = ROOT / "packages" / "leann-backend-hnsw"
+APPS_DIR = ROOT / "apps"
+
+# Prepend precise paths so the core module name `leann` resolves to leann-core
+for p in [CORE_SRC, HNSW_PKG_DIR, APPS_DIR]:
+    p_str = str(p)
+    if p_str not in sys.path:
+        sys.path.insert(0, p_str)
+
+# Defer non-stdlib imports until after sys.path setup within functions (avoid E402)
+
+
+def _load_documents(data_dir: str, required_exts: Optional[list[str]] = None) -> list[Any]:
+    from llama_index.core import SimpleDirectoryReader  # type: ignore
+
+    reader_kwargs: dict[str, Any] = {"recursive": True, "encoding": "utf-8"}
+    if required_exts:
+        reader_kwargs["required_exts"] = required_exts
+    documents = SimpleDirectoryReader(data_dir, **reader_kwargs).load_data(show_progress=True)
+    return documents
+
+
+def _ensure_index_dir(index_dir: Path) -> None:
+    index_dir.mkdir(parents=True, exist_ok=True)
+
+
+def _index_files(index_path: Path) -> tuple[Path, Path, Path]:
+    """Return (passages.jsonl, passages.idx, index.index) paths for a given index base path.
+
+    Note: HNSWBackend writes the FAISS index using the stem (without .leann),
+    i.e., for base 'documents.leann' the file is 'documents.index'. We prefer the
+    existing file among candidates.
+    """
+    passages_file = index_path.parent / f"{index_path.name}.passages.jsonl"
+    offsets_file = index_path.parent / f"{index_path.name}.passages.idx"
+    candidate_name_index = index_path.parent / f"{index_path.name}.index"
+    candidate_stem_index = index_path.parent / f"{index_path.stem}.index"
+    index_file = candidate_stem_index if candidate_stem_index.exists() else candidate_name_index
+    return passages_file, offsets_file, index_file
+
+
+def _read_meta(index_path: Path) -> dict[str, Any]:
+    meta_path = index_path.parent / f"{index_path.name}.meta.json"
+    if not meta_path.exists():
+        raise FileNotFoundError(f"Metadata file not found: {meta_path}")
+    with open(meta_path, encoding="utf-8") as f:
+        return json.load(f)
+
+
+def _autodetect_index_base(index_dir: Path) -> Optional[Path]:
+    """If exactly one *.leann.meta.json exists, return its base path (without .meta.json)."""
+    candidates = list(index_dir.glob("*.leann.meta.json"))
+    if len(candidates) == 1:
+        meta = candidates[0]
+        base = meta.with_suffix("")  # remove .json
+        base = base.with_suffix("")  # remove .meta
+        return base
+    return None
+
+
+def _load_offset_map(offsets_file: Path) -> dict[str, int]:
+    if not offsets_file.exists():
+        return {}
+    with open(offsets_file, "rb") as f:
+        return pickle.load(f)
+
+
+def _next_numeric_id(existing_ids: list[str]) -> int:
+    numeric_ids = [int(x) for x in existing_ids if x.isdigit()]
+    if not numeric_ids:
+        return 0
+    return max(numeric_ids) + 1
+
+
+def build_base_index(
+    base_dir: str,
+    index_dir: str,
+    index_name: str,
+    embedding_model: str,
+    embedding_mode: str,
+    chunk_size: int,
+    chunk_overlap: int,
+    file_types: Optional[list[str]] = None,
+    max_items: int = -1,
+) -> str:
+    print(f"Building base index from: {base_dir}")
+    documents = _load_documents(base_dir, required_exts=file_types)
+    if not documents:
+        raise ValueError(f"No documents found in base_dir: {base_dir}")
+
+    from chunking import create_text_chunks
+
+    texts = create_text_chunks(
+        documents,
+        chunk_size=chunk_size,
+        chunk_overlap=chunk_overlap,
+        use_ast_chunking=False,
+    )
+    if max_items > 0 and len(texts) > max_items:
+        texts = texts[:max_items]
+        print(f"Limiting to {max_items} chunks")
+
+    index_dir_path = Path(index_dir)
+    _ensure_index_dir(index_dir_path)
+    index_path = index_dir_path / index_name
+
+    print("Creating HNSW index with no-recompute (non-compact)...")
+    from leann.api import LeannBuilder
+    from leann.registry import register_project_directory
+
+    builder = LeannBuilder(
+        backend_name="hnsw",
+        embedding_model=embedding_model,
+        embedding_mode=embedding_mode,
+        is_recompute=False,
+        is_compact=False,
+    )
+    for t in texts:
+        builder.add_text(t)
+    builder.build_index(str(index_path))
+
+    # Register for discovery
+    register_project_directory(Path.cwd())
+
+    print(f"Base index built at: {index_path}")
+    return str(index_path)
+
+
+def add_incremental(
+    add_dir: str,
+    index_dir: str,
+    index_name: Optional[str] = None,
+    embedding_model: Optional[str] = None,
+    embedding_mode: Optional[str] = None,
+    chunk_size: int = 256,
+    chunk_overlap: int = 128,
+    file_types: Optional[list[str]] = None,
+    max_items: int = -1,
+) -> str:
+    print(f"Adding incremental data from: {add_dir}")
+    index_dir_path = Path(index_dir)
+    index_path = index_dir_path / (index_name or "documents.leann")
+
+    # If specified base doesn't exist, try to auto-detect an existing base
+    meta = None
+    try:
+        meta = _read_meta(index_path)
+    except FileNotFoundError:
+        auto_base = _autodetect_index_base(index_dir_path)
+        if auto_base is not None:
+            print(f"Auto-detected index base: {auto_base.name}")
+            index_path = auto_base
+            meta = _read_meta(index_path)
+        else:
+            raise FileNotFoundError(
+                f"No index metadata found for base '{index_path.name}'. Build base first with --build-base "
+                f"or provide --index-name to match an existing index (e.g., 'test_doc_files.leann')."
+            )
+
+    passages_file, offsets_file, faiss_index_file = _index_files(index_path)
+
+    if meta.get("backend_name") != "hnsw":
+        raise RuntimeError("Incremental add is currently supported only for HNSW backend")
+    if meta.get("is_compact", True):
+        raise RuntimeError(
+            "Index is compact. Rebuild base with --no-recompute and --no-compact for incremental add."
+        )
+
+    # Ensure the vector index exists before appending passages
+    if not faiss_index_file.exists():
+        raise FileNotFoundError(
+            f"Vector index file missing: {faiss_index_file}. Build base first (use --build-base)."
+        )
+
+    # Resolve embedding config from meta if not provided
+    emb_model = embedding_model or meta.get("embedding_model", "facebook/contriever")
+    emb_mode = embedding_mode or meta.get("embedding_mode", "sentence-transformers")
+
+    documents = _load_documents(add_dir, required_exts=file_types)
+    if not documents:
+        raise ValueError(f"No documents found in add_dir: {add_dir}")
+
+    from chunking import create_text_chunks
+
+    new_texts = create_text_chunks(
+        documents,
+        chunk_size=chunk_size,
+        chunk_overlap=chunk_overlap,
+        use_ast_chunking=False,
+    )
+    if max_items > 0 and len(new_texts) > max_items:
+        new_texts = new_texts[:max_items]
+        print(f"Limiting to {max_items} chunks (incremental)")
+
+    if not new_texts:
+        print("No new chunks to add.")
+        return str(index_path)
+
+    # Load and extend passages + offsets
+    offset_map = _load_offset_map(offsets_file)
+    start_id_int = _next_numeric_id(list(offset_map.keys()))
+    next_id = start_id_int
+
+    # Append to passages.jsonl and collect offsets
+    print("Appending passages and updating offsets...")
+    with open(passages_file, "a", encoding="utf-8") as f:
+        for text in new_texts:
+            offset = f.tell()
+            str_id = str(next_id)
+            json.dump({"id": str_id, "text": text, "metadata": {}}, f, ensure_ascii=False)
+            f.write("\n")
+            offset_map[str_id] = offset
+            next_id += 1
+
+    with open(offsets_file, "wb") as f:
+        pickle.dump(offset_map, f)
+
+    # Compute embeddings for new texts
+    print("Computing embeddings for incremental chunks...")
+    from leann.api import compute_embeddings
+
+    embeddings = compute_embeddings(
+        new_texts,
+        model_name=emb_model,
+        mode=emb_mode,
+        use_server=False,
+        is_build=True,
+    )
+
+    # Load FAISS HNSW index and add vectors, then write back
+    print("Loading HNSW index and appending vectors...")
+    try:
+        from leann_backend_hnsw import faiss as hnsw_faiss  # type: ignore
+    except Exception as e:  # pragma: no cover - environment-specific
+        raise RuntimeError(
+            "Failed to import leann_backend_hnsw.faiss. Ensure backend is built/installed."
+        ) from e
+
+    # Read existing index
+    # Read existing index (basic read is sufficient for appending)
+    index = hnsw_faiss.read_index(str(faiss_index_file), hnsw_faiss.IO_FLAG_MMAP)
+
+    # Normalize for cosine if needed
+    distance_metric = meta.get("backend_kwargs", {}).get("distance_metric", "mips").lower()
+    if distance_metric == "cosine":
+        import numpy as _np
+
+        norms = _np.linalg.norm(embeddings, axis=1, keepdims=True)
+        norms[norms == 0] = 1
+        embeddings = embeddings / norms
+
+    # Ensure dtype float32 and contiguous
+    import numpy as _np
+
+    if embeddings.dtype != _np.float32:
+        embeddings = embeddings.astype(_np.float32)
+    if not embeddings.flags.c_contiguous:
+        embeddings = _np.ascontiguousarray(embeddings, dtype=_np.float32)
+
+    # Append using FAISS-style signature (n, swig_ptr(x)); fall back to Python wrapper if needed
+    try:
+        index.add(embeddings.shape[0], hnsw_faiss.swig_ptr(embeddings))
+    except TypeError:
+        # Some builds expose a Python-friendly signature: index.add(np.ndarray)
+        index.add(embeddings)
+    hnsw_faiss.write_index(index, str(faiss_index_file))
+
+    print(f"Incremental add completed. Index updated at: {index_path}")
+    return str(index_path)
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Dynamic add to LEANN HNSW index without recompute",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+    )
+
+    parser.add_argument("--build-base", action="store_true", help="Build base index")
+    parser.add_argument("--add-incremental", action="store_true", help="Add incremental data")
+
+    parser.add_argument(
+        "--base-dir",
+        type=str,
+        default="/Users/yichuan/Desktop/code/LEANN/leann/data",
+        help="Base data directory",
+    )
+    parser.add_argument(
+        "--add-dir",
+        type=str,
+        default="/Users/yichuan/Desktop/code/LEANN/leann/test_add",
+        help="Incremental data directory",
+    )
+    parser.add_argument(
+        "--index-dir",
+        type=str,
+        default="./test_doc_files",
+        help="Directory containing the index",
+    )
+    parser.add_argument(
+        "--index-name",
+        type=str,
+        default="documents.leann",
+        help=(
+            "Index base file name. If you built via document_rag.py, use 'test_doc_files.leann'. "
+            "Default: documents.leann"
+        ),
+    )
+
+    parser.add_argument(
+        "--embedding-model",
+        type=str,
+        default="facebook/contriever",
+        help="Embedding model name",
+    )
+    parser.add_argument(
+        "--embedding-mode",
+        type=str,
+        default="sentence-transformers",
+        choices=["sentence-transformers", "openai", "mlx", "ollama"],
+        help="Embedding backend mode",
+    )
+
+    parser.add_argument("--chunk-size", type=int, default=256)
+    parser.add_argument("--chunk-overlap", type=int, default=128)
+    parser.add_argument("--file-types", nargs="+", default=None)
+    parser.add_argument("--max-items", type=int, default=-1)
+
+    args = parser.parse_args()
+
+    if not args.build_base and not args.add_incremental:
+        print("Nothing to do. Use --build-base and/or --add-incremental.")
+        return
+
+    index_path_str: Optional[str] = None
+
+    if args.build_base:
+        index_path_str = build_base_index(
+            base_dir=args.base_dir,
+            index_dir=args.index_dir,
+            index_name=args.index_name,
+            embedding_model=args.embedding_model,
+            embedding_mode=args.embedding_mode,
+            chunk_size=args.chunk_size,
+            chunk_overlap=args.chunk_overlap,
+            file_types=args.file_types,
+            max_items=args.max_items,
+        )
+
+    if args.add_incremental:
+        index_path_str = add_incremental(
+            add_dir=args.add_dir,
+            index_dir=args.index_dir,
+            index_name=args.index_name,
+            embedding_model=args.embedding_model,
+            embedding_mode=args.embedding_mode,
+            chunk_size=args.chunk_size,
+            chunk_overlap=args.chunk_overlap,
+            file_types=args.file_types,
+            max_items=args.max_items,
+        )
+
+    # Optional: quick test query using searcher
+    if index_path_str:
+        try:
+            from leann.api import LeannSearcher
+
+            searcher = LeannSearcher(index_path_str)
+            query = "what is LEANN?"
+            if args.add_incremental:
+                query = "what is the multi vector search and how it works?"
+            results = searcher.search(query, top_k=5, recompute_embeddings=False)
+            if results:
+                print(f"Sample result: {results[0].text[:80]}...")
+        except Exception:
+            pass
+
+
+if __name__ == "__main__":
+    main()