fix: Use uv venv for Arch Linux CI wheel installation

- Use astral-sh/setup-uv@v4 action for consistency with other jobs
- Create virtual environment with uv venv to bypass PEP 668 restrictions
- Install wheels using uv pip install for faster dependency resolution
- Maintain tool consistency across the entire CI pipeline

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/build-reusable.yml

@@ -87,7 +87,7 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           ref: ${{ inputs.ref }}
           submodules: recursive
@@ -98,21 +98,23 @@ jobs:
           python-version: ${{ matrix.python }}
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v4
+        uses: astral-sh/setup-uv@v6
 
       - name: Install system dependencies (Ubuntu)
         if: runner.os == 'Linux'
         run: |
           sudo apt-get update
           sudo apt-get install -y libomp-dev libboost-all-dev protobuf-compiler libzmq3-dev \
-            pkg-config libopenblas-dev patchelf libabsl-dev libaio-dev libprotobuf-dev
+            pkg-config libabsl-dev libaio-dev libprotobuf-dev \
+            patchelf
 
           # Install Intel MKL for DiskANN
           wget -q https://registrationcenter-download.intel.com/akdlm/IRC_NAS/79153e0f-74d7-45af-b8c2-258941adf58a/intel-onemkl-2025.0.0.940.sh
           sudo sh intel-onemkl-2025.0.0.940.sh -a --components intel.oneapi.lin.mkl.devel --action install --eula accept -s
           source /opt/intel/oneapi/setvars.sh
           echo "MKLROOT=/opt/intel/oneapi/mkl/latest" >> $GITHUB_ENV
-          echo "LD_LIBRARY_PATH=/opt/intel/oneapi/mkl/latest/lib/intel64:$LD_LIBRARY_PATH" >> $GITHUB_ENV
+          echo "LD_LIBRARY_PATH=/opt/intel/oneapi/compiler/latest/linux/compiler/lib/intel64_lin" >> $GITHUB_ENV
+          echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/opt/intel/oneapi/mkl/latest/lib/intel64" >> $GITHUB_ENV
 
       - name: Install system dependencies (macOS)
         if: runner.os == 'macOS'
@@ -304,3 +306,53 @@ jobs:
         with:
           name: packages-${{ matrix.os }}-py${{ matrix.python }}
           path: packages/*/dist/
+
+
+  arch-smoke:
+    name: Arch Linux smoke test (install & import)
+    needs: build
+    runs-on: ubuntu-latest
+    container:
+      image: archlinux:latest
+
+    steps:
+      - name: Prepare system
+        run: |
+          pacman -Syu --noconfirm
+          pacman -S --noconfirm python python-pip gcc git zlib openssl
+
+      - name: Download ALL wheel artifacts from this run
+        uses: actions/download-artifact@v5
+        with:
+          # Don't specify name, download all artifacts
+          path: ./wheels
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v6
+
+      - name: Create virtual environment and install wheels
+        run: |
+          uv venv
+          source .venv/bin/activate || source .venv/Scripts/activate
+          uv pip install --find-links wheels leann-core
+          uv pip install --find-links wheels leann-backend-hnsw
+          uv pip install --find-links wheels leann-backend-diskann
+          uv pip install --find-links wheels leann
+
+      - name: Import & tiny runtime check
+        env:
+          OMP_NUM_THREADS: 1
+          MKL_NUM_THREADS: 1
+        run: |
+          source .venv/bin/activate || source .venv/Scripts/activate
+          python - <<'PY'
+          import leann
+          import leann_backend_hnsw as h
+          import leann_backend_diskann as d
+          from leann import LeannBuilder, LeannSearcher
+          b = LeannBuilder(backend_name="hnsw")
+          b.add_text("hello arch")
+          b.build_index("arch_demo.leann")
+          s = LeannSearcher("arch_demo.leann")
+          print("search:", s.search("hello", top_k=1))
+          PY

.github/workflows/link-check.yml

@@ -14,6 +14,6 @@ jobs:
       - uses: actions/checkout@v4
       - uses: lycheeverse/lychee-action@v2
         with:
-          args: --no-progress --insecure README.md docs/ apps/ examples/ benchmarks/
+          args: --no-progress --insecure --user-agent 'curl/7.68.0' README.md docs/ apps/ examples/ benchmarks/
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -18,6 +18,7 @@ demo/experiment_results/**/*.json
 *.eml
 *.emlx
 *.json
+!.vscode/*.json
 *.sh
 *.txt
 !CMakeLists.txt

.vscode/extensions.json

@@ -0,0 +1,5 @@
+{
+    "recommendations": [
+        "charliermarsh.ruff",
+    ]
+}

.vscode/settings.json

@@ -0,0 +1,22 @@
+{
+  "python.defaultInterpreterPath": ".venv/bin/python",
+  "python.terminal.activateEnvironment": true,
+  "[python]": {
+    "editor.defaultFormatter": "charliermarsh.ruff",
+    "editor.formatOnSave": true,
+    "editor.codeActionsOnSave": {
+      "source.organizeImports": "explicit",
+      "source.fixAll": "explicit"
+    },
+    "editor.insertSpaces": true,
+    "editor.tabSize": 4
+  },
+  "ruff.enable": true,
+  "files.watcherExclude": {
+    "**/.venv/**": true,
+    "**/__pycache__/**": true,
+    "**/*.egg-info/**": true,
+    "**/build/**": true,
+    "**/dist/**": true
+  }
+}

README.md

@@ -87,17 +87,60 @@ git submodule update --init --recursive
 ```
 
 **macOS:**
+
+Note: DiskANN requires MacOS 13.3 or later.
+
 ```bash
-brew install llvm libomp boost protobuf zeromq pkgconf
-CC=$(brew --prefix llvm)/bin/clang CXX=$(brew --prefix llvm)/bin/clang++ uv sync
+brew install libomp boost protobuf zeromq pkgconf
+uv sync --extra diskann
 ```
 
-**Linux:**
-```bash
-# Ubuntu/Debian (For Arch Linux: sudo pacman -S blas lapack openblas libaio boost protobuf abseil-cpp zeromq)
-sudo apt-get update && sudo apt-get install -y libomp-dev libboost-all-dev protobuf-compiler libabsl-dev libmkl-full-dev libaio-dev libzmq3-dev
+**Linux (Ubuntu/Debian):**
 
-uv sync
+Note: On Ubuntu 20.04, you may need to build a newer Abseil and pin Protobuf (e.g., v3.20.x) for building DiskANN. See [Issue #30](https://github.com/yichuan-w/LEANN/issues/30) for a step-by-step note.
+
+You can manually install [Intel oneAPI MKL](https://www.intel.com/content/www/us/en/developer/tools/oneapi/onemkl.html) instead of `libmkl-full-dev` for DiskANN. You can also use `libopenblas-dev` for building HNSW only, by removing `--extra diskann` in the command below.
+
+```bash
+sudo apt-get update && sudo apt-get install -y \
+  libomp-dev libboost-all-dev protobuf-compiler libzmq3-dev \
+  pkg-config libabsl-dev libaio-dev libprotobuf-dev \
+  libmkl-full-dev
+
+uv sync --extra diskann
+```
+
+**Linux (Arch Linux):**
+
+```bash
+sudo pacman -Syu && sudo pacman -S --needed base-devel cmake pkgconf git gcc \
+  boost boost-libs protobuf abseil-cpp libaio zeromq
+
+# For MKL in DiskANN
+sudo pacman -S --needed base-devel git
+git clone https://aur.archlinux.org/paru-bin.git
+cd paru-bin && makepkg -si
+paru -S intel-oneapi-mkl intel-oneapi-compiler
+source /opt/intel/oneapi/setvars.sh
+
+uv sync --extra diskann
+```
+
+**Linux (RHEL / CentOS Stream / Oracle / Rocky / AlmaLinux):**
+
+See [Issue #50](https://github.com/yichuan-w/LEANN/issues/50) for more details.
+
+```bash
+sudo dnf groupinstall -y "Development Tools"
+sudo dnf install -y libomp-devel boost-devel protobuf-compiler protobuf-devel \
+  abseil-cpp-devel libaio-devel zeromq-devel pkgconf-pkg-config
+
+# For MKL in DiskANN
+sudo dnf install -y intel-oneapi-mkl intel-oneapi-mkl-devel \
+  intel-oneapi-openmp || sudo dnf install -y intel-oneapi-compiler
+source /opt/intel/oneapi/setvars.sh
+
+uv sync --extra diskann
 ```
 
 </details>
@@ -542,8 +585,10 @@ Options:
 leann list
 
 # Lists all indexes across all projects with status indicators:
-# ✓ - Index is complete and ready to use
-# ✗ - Index is incomplete or corrupted
+# ✅ - Index is complete and ready to use
+# ❌ - Index is incomplete or corrupted
+# 📁 - CLI-created index (in .leann/indexes/)
+# 📄 - App-created index (*.leann.meta.json files)
 ```
 
 **Remove Command:**
@@ -557,6 +602,7 @@ Options:
 # - Shows all matching indexes across projects
 # - Requires confirmation for cross-project removal
 # - Interactive selection when multiple matches found
+# - Supports both CLI and app-created indexes
 ```
 
 </details>

apps/base_rag_example.py

@@ -10,6 +10,7 @@ from typing import Any
 
 import dotenv
 from leann.api import LeannBuilder, LeannChat
+from leann.registry import register_project_directory
 from llama_index.core.node_parser import SentenceSplitter
 
 dotenv.load_dotenv()
@@ -214,6 +215,11 @@ class BaseRAGExample(ABC):
         builder.build_index(index_path)
         print(f"Index saved to: {index_path}")
 
+        # Register project directory so leann list can discover this index
+        # The index is saved as args.index_dir/index_name.leann
+        # We want to register the current working directory where the app is run
+        register_project_directory(Path.cwd())
+
         return index_path
 
     async def run_interactive_chat(self, args, index_path: str):

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

@@ -614,7 +614,7 @@ class LeannSearcher:
             zmq_port=zmq_port,
         )
         # logger.info(f"  Generated embedding shape: {query_embedding.shape}")
-        time.time() - start_time
+        # time.time() - start_time
         # logger.info(f"  Embedding time: {embedding_time} seconds")
 
         start_time = time.time()
@@ -680,8 +680,9 @@ class LeannSearcher:
         This method should be called after you're done using the searcher,
         especially in test environments or batch processing scenarios.
         """
-        if hasattr(self.backend_impl, "embedding_server_manager"):
-            self.backend_impl.embedding_server_manager.stop_server()
+        backend = getattr(self.backend_impl, "embedding_server_manager", None)
+        if backend is not None:
+            backend.stop_server()
 
     # Enable automatic cleanup patterns
     def __enter__(self):

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

@@ -707,20 +707,28 @@ class GeminiChat(LLMInterface):
         logger.info(f"Sending request to Gemini with model {self.model}")
 
         try:
-            # Set generation configuration
-            generation_config = {
-                "temperature": kwargs.get("temperature", 0.7),
-                "max_output_tokens": kwargs.get("max_tokens", 1000),
-            }
+            from google.genai.types import GenerateContentConfig
+
+            generation_config = GenerateContentConfig(
+                temperature=kwargs.get("temperature", 0.7),
+                max_output_tokens=kwargs.get("max_tokens", 1000),
+            )
 
             # Handle top_p parameter
             if "top_p" in kwargs:
-                generation_config["top_p"] = kwargs["top_p"]
+                generation_config.top_p = kwargs["top_p"]
 
             response = self.client.models.generate_content(
-                model=self.model, contents=prompt, config=generation_config
+                model=self.model,
+                contents=prompt,
+                config=generation_config,
             )
-            return response.text.strip()
+            # Handle potential None response text
+            response_text = response.text
+            if response_text is None:
+                logger.warning("Gemini returned None response text")
+                return ""
+            return response_text.strip()
         except Exception as e:
             logger.error(f"Error communicating with Gemini: {e}")
             return f"Error: Could not get a response from Gemini. Details: {e}"

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

@@ -1,13 +1,14 @@
 import argparse
 import asyncio
 from pathlib import Path
-from typing import Union
+from typing import Optional, Union
 
 from llama_index.core import SimpleDirectoryReader
 from llama_index.core.node_parser import SentenceSplitter
 from tqdm import tqdm
 
 from .api import LeannBuilder, LeannChat, LeannSearcher
+from .registry import register_project_directory
 
 
 def extract_pdf_text_with_pymupdf(file_path: str) -> str:
@@ -263,31 +264,7 @@ Examples:
 
     def register_project_dir(self):
         """Register current project directory in global registry"""
-        global_registry = Path.home() / ".leann" / "projects.json"
-        global_registry.parent.mkdir(exist_ok=True)
-
-        current_dir = str(Path.cwd())
-
-        # Load existing registry
-        projects = []
-        if global_registry.exists():
-            try:
-                import json
-
-                with open(global_registry) as f:
-                    projects = json.load(f)
-            except Exception:
-                projects = []
-
-        # Add current directory if not already present
-        if current_dir not in projects:
-            projects.append(current_dir)
-
-        # Save registry
-        import json
-
-        with open(global_registry, "w") as f:
-            json.dump(projects, f, indent=2)
+        register_project_directory()
 
     def _build_gitignore_parser(self, docs_dir: str):
         """Build gitignore parser using gitignore-parser library."""
@@ -373,13 +350,10 @@ Examples:
             valid_projects.append(current_path)
 
         # Separate current and other projects
-        current_project = None
         other_projects = []
 
         for project_path in valid_projects:
-            if project_path == current_path:
-                current_project = project_path
-            else:
+            if project_path != current_path:
                 other_projects.append(project_path)
 
         print("📚 LEANN Indexes")
@@ -389,35 +363,20 @@ Examples:
         current_indexes_count = 0
 
         # Show current project first (most important)
-        if current_project:
-            current_indexes_dir = current_project / ".leann" / "indexes"
-            if current_indexes_dir.exists():
-                current_index_dirs = [d for d in current_indexes_dir.iterdir() if d.is_dir()]
+        print("\n🏠 Current Project")
+        print(f"   {current_path}")
+        print("   " + "─" * 45)
 
-                print("\n🏠 Current Project")
-                print(f"   {current_project}")
-                print("   " + "─" * 45)
-
-                if current_index_dirs:
-                    for index_dir in current_index_dirs:
-                        total_indexes += 1
-                        current_indexes_count += 1
-                        index_name = index_dir.name
-                        meta_file = index_dir / "documents.leann.meta.json"
-                        status = "✅" if meta_file.exists() else "❌"
-
-                        print(f"   {current_indexes_count}. {index_name} {status}")
-                        if meta_file.exists():
-                            size_mb = sum(
-                                f.stat().st_size for f in index_dir.iterdir() if f.is_file()
-                            ) / (1024 * 1024)
-                            print(f"      📦 Size: {size_mb:.1f} MB")
-                else:
-                    print("   📭 No indexes in current project")
+        current_indexes = self._discover_indexes_in_project(current_path)
+        if current_indexes:
+            for idx in current_indexes:
+                total_indexes += 1
+                current_indexes_count += 1
+                type_icon = "📁" if idx["type"] == "cli" else "📄"
+                print(f"   {current_indexes_count}. {type_icon} {idx['name']} {idx['status']}")
+                if idx["size_mb"] > 0:
+                    print(f"      📦 Size: {idx['size_mb']:.1f} MB")
         else:
-            print("\n🏠 Current Project")
-            print(f"   {current_path}")
-            print("   " + "─" * 45)
             print("   📭 No indexes in current project")
 
         # Show other projects (reference information)
@@ -426,29 +385,19 @@ Examples:
             print("   " + "─" * 45)
 
             for project_path in other_projects:
-                indexes_dir = project_path / ".leann" / "indexes"
-                if not indexes_dir.exists():
-                    continue
-
-                index_dirs = [d for d in indexes_dir.iterdir() if d.is_dir()]
-                if not index_dirs:
+                project_indexes = self._discover_indexes_in_project(project_path)
+                if not project_indexes:
                     continue
 
                 print(f"\n   📂 {project_path.name}")
                 print(f"      {project_path}")
 
-                for index_dir in index_dirs:
+                for idx in project_indexes:
                     total_indexes += 1
-                    index_name = index_dir.name
-                    meta_file = index_dir / "documents.leann.meta.json"
-                    status = "✅" if meta_file.exists() else "❌"
-
-                    print(f"      • {index_name} {status}")
-                    if meta_file.exists():
-                        size_mb = sum(
-                            f.stat().st_size for f in index_dir.iterdir() if f.is_file()
-                        ) / (1024 * 1024)
-                        print(f"        📦 {size_mb:.1f} MB")
+                    type_icon = "📁" if idx["type"] == "cli" else "📄"
+                    print(f"      • {type_icon} {idx['name']} {idx['status']}")
+                    if idx["size_mb"] > 0:
+                        print(f"        📦 {idx['size_mb']:.1f} MB")
 
         # Summary and usage info
         print("\n" + "=" * 50)
@@ -480,6 +429,67 @@ Examples:
                 print("\n💡 Create your first index:")
                 print("   leann build my-docs --docs ./documents")
 
+    def _discover_indexes_in_project(self, project_path: Path):
+        """Discover all indexes in a project directory (both CLI and apps formats)"""
+        indexes = []
+
+        # 1. CLI format: .leann/indexes/index_name/
+        cli_indexes_dir = project_path / ".leann" / "indexes"
+        if cli_indexes_dir.exists():
+            for index_dir in cli_indexes_dir.iterdir():
+                if index_dir.is_dir():
+                    meta_file = index_dir / "documents.leann.meta.json"
+                    status = "✅" if meta_file.exists() else "❌"
+
+                    size_mb = 0
+                    if meta_file.exists():
+                        try:
+                            size_mb = sum(
+                                f.stat().st_size for f in index_dir.iterdir() if f.is_file()
+                            ) / (1024 * 1024)
+                        except (OSError, PermissionError):
+                            pass
+
+                    indexes.append(
+                        {
+                            "name": index_dir.name,
+                            "type": "cli",
+                            "status": status,
+                            "size_mb": size_mb,
+                            "path": index_dir,
+                        }
+                    )
+
+        # 2. Apps format: *.leann.meta.json files anywhere in the project
+        for meta_file in project_path.rglob("*.leann.meta.json"):
+            if meta_file.is_file():
+                # Extract index name from filename (remove .leann.meta.json extension)
+                index_name = meta_file.name.replace(".leann.meta.json", "")
+
+                # Apps indexes are considered complete if the .leann.meta.json file exists
+                status = "✅"
+
+                # Calculate total size of all related files
+                size_mb = 0
+                try:
+                    index_dir = meta_file.parent
+                    for related_file in index_dir.glob(f"{index_name}.leann*"):
+                        size_mb += related_file.stat().st_size / (1024 * 1024)
+                except (OSError, PermissionError):
+                    pass
+
+                indexes.append(
+                    {
+                        "name": index_name,
+                        "type": "app",
+                        "status": status,
+                        "size_mb": size_mb,
+                        "path": meta_file,
+                    }
+                )
+
+        return indexes
+
     def remove_index(self, index_name: str, force: bool = False):
         """Safely remove an index - always show all matches for transparency"""
 
@@ -637,7 +647,7 @@ Examples:
             return False
 
     def _delete_index_directory(
-        self, index_dir: Path, index_name: str, project_path: Path | None = None
+        self, index_dir: Path, index_name: str, project_path: Optional[Path] = None
     ):
         """Actually delete the index directory"""
         try:

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

@@ -2,8 +2,10 @@
 
 import importlib
 import importlib.metadata
+import json
 import logging
-from typing import TYPE_CHECKING
+from pathlib import Path
+from typing import TYPE_CHECKING, Optional, Union
 
 if TYPE_CHECKING:
     from leann.interface import LeannBackendFactoryInterface
@@ -43,3 +45,54 @@ def autodiscover_backends():
             # print(f"WARN: Could not import backend module '{backend_module_name}': {e}")
             pass
     # print("INFO: Backend auto-discovery finished.")
+
+
+def register_project_directory(project_dir: Optional[Union[str, Path]] = None):
+    """
+    Register a project directory in the global LEANN registry.
+
+    This allows `leann list` to discover indexes created by apps or other tools.
+
+    Args:
+        project_dir: Directory to register. If None, uses current working directory.
+    """
+    if project_dir is None:
+        project_dir = Path.cwd()
+    else:
+        project_dir = Path(project_dir)
+
+    # Only register directories that have some kind of LEANN content
+    # Either .leann/indexes/ (CLI format) or *.leann.meta.json files (apps format)
+    has_cli_indexes = (project_dir / ".leann" / "indexes").exists()
+    has_app_indexes = any(project_dir.rglob("*.leann.meta.json"))
+
+    if not (has_cli_indexes or has_app_indexes):
+        # Don't register if there are no LEANN indexes
+        return
+
+    global_registry = Path.home() / ".leann" / "projects.json"
+    global_registry.parent.mkdir(exist_ok=True)
+
+    project_str = str(project_dir.resolve())
+
+    # Load existing registry
+    projects = []
+    if global_registry.exists():
+        try:
+            with open(global_registry) as f:
+                projects = json.load(f)
+        except Exception:
+            logger.debug("Could not load existing project registry")
+            projects = []
+
+    # Add project if not already present
+    if project_str not in projects:
+        projects.append(project_str)
+
+        # Save updated registry
+        try:
+            with open(global_registry, "w") as f:
+                json.dump(projects, f, indent=2)
+            logger.debug(f"Registered project directory: {project_str}")
+        except Exception as e:
+            logger.warning(f"Could not save project registry: {e}")

pyproject.toml

@@ -14,8 +14,6 @@ dependencies = [
     "numpy>=1.26.0",
     "torch",
     "tqdm",
-    "flask",
-    "flask_compress",
     "datasets>=2.15.0",
     "evaluate",
     "colorama",
@@ -66,9 +64,7 @@ test = [
     "pytest>=7.0",
     "pytest-timeout>=2.0",
     "llama-index-core>=0.12.0",
-    "llama-index-readers-file>=0.4.0",
     "python-dotenv>=1.0.0",
-    "sentence-transformers>=2.2.0",
 ]
 
 diskann = [
@@ -100,13 +96,8 @@ leann-backend-hnsw = { path = "packages/leann-backend-hnsw", editable = true }
 [tool.ruff]
 target-version = "py39"
 line-length = 100
-extend-exclude = [
-    "third_party",
-    "*.egg-info",
-    "__pycache__",
-    ".git",
-    ".venv",
-]
+extend-exclude = ["third_party"]
+
 
 [tool.ruff.lint]
 select = [
@@ -129,21 +120,12 @@ ignore = [
     "RUF012", # mutable class attributes should be annotated with typing.ClassVar
 ]
 
-[tool.ruff.lint.per-file-ignores]
-"test/**/*.py" = ["E402"]      # module level import not at top of file (common in tests)
-"examples/**/*.py" = ["E402"]  # module level import not at top of file (common in examples)
-
 [tool.ruff.format]
 quote-style = "double"
 indent-style = "space"
 skip-magic-trailing-comma = false
 line-ending = "auto"
 
-[dependency-groups]
-dev = [
-    "ruff>=0.12.4",
-]
-
 [tool.lychee]
 accept = ["200", "403", "429", "503"]
 timeout = 20