chore(submodule): bump astchunk-leann to latest main

* Add grep search functionality to LeannSearcher

- Add use_grep parameter to search method
- Implement grep-based search on .jsonl files
- Add fallback Python regex search
- Support same SearchResult format as semantic search

Addresses issue #86

* fix: resolve linting errors

* docs: add grep search example

* docs: add grep search to README examples

* refactor: remove regex fallback, move grep example to features section

* docs: add grep search to Advanced Features with comprehensive guide

.gitignore

@@ -22,6 +22,7 @@ demo/experiment_results/**/*.json
 *.sh
 *.txt
 !CMakeLists.txt
+!llms.txt
 latency_breakdown*.json
 experiment_results/eval_results/diskann/*.json
 aws/

.gitmodules

@@ -14,3 +14,7 @@
 [submodule "packages/leann-backend-hnsw/third_party/libzmq"]
 	path = packages/leann-backend-hnsw/third_party/libzmq
 	url = https://github.com/zeromq/libzmq.git
+[submodule "packages/astchunk-leann"]
+	path = packages/astchunk-leann
+	url = git@github.com:yichuan-w/astchunk-leann.git
+	branch = main

README.md

@@ -656,6 +656,19 @@ results = searcher.search(
 
 📖 **[Complete Metadata filtering guide →](docs/metadata_filtering.md)**
 
+### 🔍 Grep Search
+
+For exact text matching instead of semantic search, use the `use_grep` parameter:
+
+```python
+# Exact text search
+results = searcher.search("banana‑crocodile", use_grep=True, top_k=1)
+```
+
+**Use cases**: Finding specific code patterns, error messages, function names, or exact phrases where semantic similarity isn't needed.
+
+📖 **[Complete grep search guide →](docs/grep_search.md)**
+
 ## 🏗️ Architecture & How It Works
 
 <p align="center">

docs/ast_chunking_guide.md

@@ -26,6 +26,21 @@ leann build my-code-index --docs ./src --use-ast-chunking
 uv pip install -e "."
 ```
 
+#### For normal users (PyPI install)
+- Use `pip install leann` or `uv pip install leann`.
+- `astchunk` is pulled automatically from PyPI as a dependency; no extra steps.
+
+#### For developers (from source, editable)
+```bash
+git clone https://github.com/yichuan-w/LEANN.git leann
+cd leann
+git submodule update --init --recursive
+uv sync
+```
+- This repo vendors `astchunk` as a git submodule at `packages/astchunk-leann` (our fork).
+- `[tool.uv.sources]` maps the `astchunk` package to that path in editable mode.
+- You can edit code under `packages/astchunk-leann` and Python will use your changes immediately (no separate `pip install astchunk` needed).
+
 ## Best Practices
 
 ### When to Use AST Chunking

docs/grep_search.md

@@ -0,0 +1,149 @@
+# LEANN Grep Search Usage Guide
+
+## Overview
+
+LEANN's grep search functionality provides exact text matching for finding specific code patterns, error messages, function names, or exact phrases in your indexed documents.
+
+## Basic Usage
+
+### Simple Grep Search
+
+```python
+from leann.api import LeannSearcher
+
+searcher = LeannSearcher("your_index_path")
+
+# Exact text search
+results = searcher.search("def authenticate_user", use_grep=True, top_k=5)
+
+for result in results:
+    print(f"Score: {result.score}")
+    print(f"Text: {result.text[:100]}...")
+    print("-" * 40)
+```
+
+### Comparison: Semantic vs Grep Search
+
+```python
+# Semantic search - finds conceptually similar content
+semantic_results = searcher.search("machine learning algorithms", top_k=3)
+
+# Grep search - finds exact text matches
+grep_results = searcher.search("def train_model", use_grep=True, top_k=3)
+```
+
+## When to Use Grep Search
+
+### Use Cases
+
+- **Code Search**: Finding specific function definitions, class names, or variable references
+- **Error Debugging**: Locating exact error messages or stack traces
+- **Documentation**: Finding specific API endpoints or exact terminology
+
+### Examples
+
+```python
+# Find function definitions
+functions = searcher.search("def __init__", use_grep=True)
+
+# Find import statements
+imports = searcher.search("from sklearn import", use_grep=True)
+
+# Find specific error types
+errors = searcher.search("FileNotFoundError", use_grep=True)
+
+# Find TODO comments
+todos = searcher.search("TODO:", use_grep=True)
+
+# Find configuration entries
+configs = searcher.search("server_port=", use_grep=True)
+```
+
+## Technical Details
+
+### How It Works
+
+1. **File Location**: Grep search operates on the raw text stored in `.jsonl` files
+2. **Command Execution**: Uses the system `grep` command with case-insensitive search
+3. **Result Processing**: Parses JSON lines and extracts text and metadata
+4. **Scoring**: Simple frequency-based scoring based on query term occurrences
+
+### Search Process
+
+```
+Query: "def train_model"
+  ↓
+grep -i -n "def train_model" documents.leann.passages.jsonl
+  ↓
+Parse matching JSON lines
+  ↓
+Calculate scores based on term frequency
+  ↓
+Return top_k results
+```
+
+### Scoring Algorithm
+
+```python
+# Term frequency in document
+score = text.lower().count(query.lower())
+```
+
+Results are ranked by score (highest first), with higher scores indicating more occurrences of the search term.
+
+## Error Handling
+
+### Common Issues
+
+#### Grep Command Not Found
+```
+RuntimeError: grep command not found. Please install grep or use semantic search.
+```
+
+**Solution**: Install grep on your system:
+- **Ubuntu/Debian**: `sudo apt-get install grep`
+- **macOS**: grep is pre-installed
+- **Windows**: Use WSL or install grep via Git Bash/MSYS2
+
+#### No Results Found
+```python
+# Check if your query exists in the raw data
+results = searcher.search("your_query", use_grep=True)
+if not results:
+    print("No exact matches found. Try:")
+    print("1. Check spelling and case")
+    print("2. Use partial terms")
+    print("3. Switch to semantic search")
+```
+
+## Complete Example
+
+```python
+#!/usr/bin/env python3
+"""
+Grep Search Example
+Demonstrates grep search for exact text matching.
+"""
+
+from leann.api import LeannSearcher
+
+def demonstrate_grep_search():
+    # Initialize searcher
+    searcher = LeannSearcher("my_index")
+
+    print("=== Function Search ===")
+    functions = searcher.search("def __init__", use_grep=True, top_k=5)
+    for i, result in enumerate(functions, 1):
+        print(f"{i}. Score: {result.score}")
+        print(f"   Preview: {result.text[:60]}...")
+        print()
+
+    print("=== Error Search ===")
+    errors = searcher.search("FileNotFoundError", use_grep=True, top_k=3)
+    for result in errors:
+        print(f"Content: {result.text.strip()}")
+        print("-" * 40)
+
+if __name__ == "__main__":
+    demonstrate_grep_search()
+```

examples/grep_search_example.py

@@ -0,0 +1,35 @@
+"""
+Grep Search Example
+
+Shows how to use grep-based text search instead of semantic search.
+Useful when you need exact text matches rather than meaning-based results.
+"""
+
+from leann import LeannSearcher
+
+# Load your index
+searcher = LeannSearcher("my-documents.leann")
+
+# Regular semantic search
+print("=== Semantic Search ===")
+results = searcher.search("machine learning algorithms", top_k=3)
+for result in results:
+    print(f"Score: {result.score:.3f}")
+    print(f"Text: {result.text[:80]}...")
+    print()
+
+# Grep-based search for exact text matches
+print("=== Grep Search ===")
+results = searcher.search("def train_model", top_k=3, use_grep=True)
+for result in results:
+    print(f"Score: {result.score}")
+    print(f"Text: {result.text[:80]}...")
+    print()
+
+# Find specific error messages
+error_results = searcher.search("FileNotFoundError", use_grep=True)
+print(f"Found {len(error_results)} files mentioning FileNotFoundError")
+
+# Search for function definitions
+func_results = searcher.search("class SearchResult", use_grep=True, top_k=5)
+print(f"Found {len(func_results)} class definitions")

llms.txt

@@ -0,0 +1,28 @@
+# llms.txt — LEANN MCP and Agent Integration
+product: LEANN
+homepage: https://github.com/yichuan-w/LEANN
+contact: https://github.com/yichuan-w/LEANN/issues
+
+# Installation
+install: uv tool install leann-core --with leann
+
+# MCP Server Entry Point
+mcp.server: leann_mcp
+mcp.protocol_version: 2024-11-05
+
+# Tools
+mcp.tools: leann_list, leann_search
+
+mcp.tool.leann_list.description: List available LEANN indexes
+mcp.tool.leann_list.input: {}
+
+mcp.tool.leann_search.description: Semantic search across a named LEANN index
+mcp.tool.leann_search.input.index_name: string, required
+mcp.tool.leann_search.input.query: string, required
+mcp.tool.leann_search.input.top_k: integer, optional, default=5, min=1, max=20
+mcp.tool.leann_search.input.complexity: integer, optional, default=32, min=16, max=128
+
+# Notes
+note: Build indexes with `leann build <name> --docs <files...>` before searching.
+example.add: claude mcp add --scope user leann-server -- leann_mcp
+example.verify: claude mcp list | cat

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

@@ -6,6 +6,8 @@ with the correct, original embedding logic from the user's reference code.
 import json
 import logging
 import pickle
+import re
+import subprocess
 import time
 import warnings
 from dataclasses import dataclass, field
@@ -653,6 +655,7 @@ class LeannSearcher:
         expected_zmq_port: int = 5557,
         metadata_filters: Optional[dict[str, dict[str, Union[str, int, float, bool, list]]]] = None,
         batch_size: int = 0,
+        use_grep: bool = False,
         **kwargs,
     ) -> list[SearchResult]:
         """
@@ -679,6 +682,10 @@ class LeannSearcher:
         Returns:
             List of SearchResult objects with text, metadata, and similarity scores
         """
+        # Handle grep search
+        if use_grep:
+            return self._grep_search(query, top_k)
+
         logger.info("🔍 LeannSearcher.search() called:")
         logger.info(f"  Query: '{query}'")
         logger.info(f"  Top_k: {top_k}")
@@ -795,9 +802,96 @@ class LeannSearcher:
         logger.info(f"  {GREEN}✓ Final enriched results: {len(enriched_results)} passages{RESET}")
         return enriched_results
 
+    def _find_jsonl_file(self) -> Optional[str]:
+        """Find the .jsonl file containing raw passages for grep search"""
+        index_path = Path(self.meta_path_str).parent
+        potential_files = [
+            index_path / "documents.leann.passages.jsonl",
+            index_path.parent / "documents.leann.passages.jsonl",
+        ]
+
+        for file_path in potential_files:
+            if file_path.exists():
+                return str(file_path)
+        return None
+
+    def _grep_search(self, query: str, top_k: int = 5) -> list[SearchResult]:
+        """Perform grep-based search on raw passages"""
+        jsonl_file = self._find_jsonl_file()
+        if not jsonl_file:
+            raise FileNotFoundError("No .jsonl passages file found for grep search")
+
+        try:
+            cmd = ["grep", "-i", "-n", query, jsonl_file]
+            result = subprocess.run(cmd, capture_output=True, text=True, check=False)
+
+            if result.returncode == 1:
+                return []
+            elif result.returncode != 0:
+                raise RuntimeError(f"Grep failed: {result.stderr}")
+
+            matches = []
+            for line in result.stdout.strip().split("\n"):
+                if not line:
+                    continue
+                parts = line.split(":", 1)
+                if len(parts) != 2:
+                    continue
+
+                try:
+                    data = json.loads(parts[1])
+                    text = data.get("text", "")
+                    score = text.lower().count(query.lower())
+
+                    matches.append(
+                        SearchResult(
+                            id=data.get("id", parts[0]),
+                            text=text,
+                            metadata=data.get("metadata", {}),
+                            score=float(score),
+                        )
+                    )
+                except json.JSONDecodeError:
+                    continue
+
+            matches.sort(key=lambda x: x.score, reverse=True)
+            return matches[:top_k]
+
+        except FileNotFoundError:
+            raise RuntimeError(
+                "grep command not found. Please install grep or use semantic search."
+            )
+
+    def _python_regex_search(self, query: str, top_k: int = 5) -> list[SearchResult]:
+        """Fallback regex search"""
+        jsonl_file = self._find_jsonl_file()
+        if not jsonl_file:
+            raise FileNotFoundError("No .jsonl file found")
+
+        pattern = re.compile(re.escape(query), re.IGNORECASE)
+        matches = []
+
+        with open(jsonl_file, encoding="utf-8") as f:
+            for line_num, line in enumerate(f, 1):
+                if pattern.search(line):
+                    try:
+                        data = json.loads(line.strip())
+                        matches.append(
+                            SearchResult(
+                                id=data.get("id", str(line_num)),
+                                text=data.get("text", ""),
+                                metadata=data.get("metadata", {}),
+                                score=float(len(pattern.findall(data.get("text", "")))),
+                            )
+                        )
+                    except json.JSONDecodeError:
+                        continue
+
+        matches.sort(key=lambda x: x.score, reverse=True)
+        return matches[:top_k]
+
     def cleanup(self):
         """Explicitly cleanup embedding server resources.
-
         This method should be called after you're done using the searcher,
         especially in test environments or batch processing scenarios.
         """
@@ -853,6 +947,7 @@ class LeannChat:
         expected_zmq_port: int = 5557,
         metadata_filters: Optional[dict[str, dict[str, Union[str, int, float, bool, list]]]] = None,
         batch_size: int = 0,
+        use_grep: bool = False,
         **search_kwargs,
     ):
         if llm_kwargs is None:

packages/leann-mcp/README.md

@@ -2,6 +2,8 @@
 
 Transform your development workflow with intelligent code assistance using LEANN's semantic search directly in Claude Code.
 
+For agent-facing discovery details, see `llms.txt` in the repository root.
+
 ## Prerequisites
 
 Install LEANN globally for MCP integration (with default backend):

pyproject.toml

@@ -99,6 +99,7 @@ wechat-exporter = "wechat_exporter.main:main"
 leann-core = { path = "packages/leann-core", editable = true }
 leann-backend-diskann = { path = "packages/leann-backend-diskann", editable = true }
 leann-backend-hnsw = { path = "packages/leann-backend-hnsw", editable = true }
+astchunk = { path = "packages/astchunk-leann", editable = true }
 
 [tool.ruff]
 target-version = "py39"

uv.lock

@@ -1,5 +1,5 @@
 version = 1
-revision = 3
+revision = 2
 requires-python = ">=3.9"
 resolution-markers = [
     "python_full_version >= '3.12'",
@@ -201,7 +201,7 @@ wheels = [
 [[package]]
 name = "astchunk"
 version = "0.1.0"
-source = { registry = "https://pypi.org/simple" }
+source = { editable = "packages/astchunk-leann" }
 dependencies = [
     { name = "numpy", version = "2.0.2", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
     { name = "numpy", version = "2.2.6", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version == '3.10.*'" },
@@ -214,10 +214,31 @@ dependencies = [
     { name = "tree-sitter-python" },
     { name = "tree-sitter-typescript" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/db/2a/7a35e2fac7d550265ae2ee40651425083b37555f921d1a1b77c3f525e0df/astchunk-0.1.0.tar.gz", hash = "sha256:f4dff0ef8b3b3bcfeac363384db1e153f74d4c825dc2e35864abfab027713be4", size = 18093, upload-time = "2025-06-19T04:37:25.34Z" }
-wheels = [
-    { url = "https://files.pythonhosted.org/packages/be/84/5433ab0e933b572750cb16fd7edf3d6c7902b069461a22ec670042752a4d/astchunk-0.1.0-py3-none-any.whl", hash = "sha256:33ada9fc3620807fdda5846fa1948af463f281a60e0d43d4f3782b6dbb416d24", size = 15396, upload-time = "2025-06-19T04:37:23.87Z" },
+
+[package.metadata]
+requires-dist = [
+    { name = "black", marker = "extra == 'dev'", specifier = ">=22.0.0" },
+    { name = "flake8", marker = "extra == 'dev'", specifier = ">=5.0.0" },
+    { name = "isort", marker = "extra == 'dev'", specifier = ">=5.10.0" },
+    { name = "mypy", marker = "extra == 'dev'", specifier = ">=1.0.0" },
+    { name = "myst-parser", marker = "extra == 'docs'", specifier = ">=0.18.0" },
+    { name = "numpy", specifier = ">=1.20.0" },
+    { name = "pre-commit", marker = "extra == 'dev'", specifier = ">=2.20.0" },
+    { name = "pyrsistent", specifier = ">=0.18.0" },
+    { name = "pytest", marker = "extra == 'dev'", specifier = ">=7.0.0" },
+    { name = "pytest", marker = "extra == 'test'", specifier = ">=7.0.0" },
+    { name = "pytest-cov", marker = "extra == 'dev'", specifier = ">=4.0.0" },
+    { name = "pytest-cov", marker = "extra == 'test'", specifier = ">=4.0.0" },
+    { name = "pytest-xdist", marker = "extra == 'test'", specifier = ">=2.5.0" },
+    { name = "sphinx", marker = "extra == 'docs'", specifier = ">=5.0.0" },
+    { name = "sphinx-rtd-theme", marker = "extra == 'docs'", specifier = ">=1.0.0" },
+    { name = "tree-sitter", specifier = ">=0.20.0" },
+    { name = "tree-sitter-c-sharp", specifier = ">=0.20.0" },
+    { name = "tree-sitter-java", specifier = ">=0.20.0" },
+    { name = "tree-sitter-python", specifier = ">=0.20.0" },
+    { name = "tree-sitter-typescript", specifier = ">=0.20.0" },
 ]
+provides-extras = ["dev", "docs", "test"]
 
 [[package]]
 name = "asttokens"
@@ -1564,7 +1585,7 @@ name = "importlib-metadata"
 version = "8.7.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
-    { name = "zipp" },
+    { name = "zipp", marker = "python_full_version < '3.10'" },
 ]
 sdist = { url = "https://files.pythonhosted.org/packages/76/66/650a33bd90f786193e4de4b3ad86ea60b53c89b669a5c7be931fac31cdb0/importlib_metadata-8.7.0.tar.gz", hash = "sha256:d13b81ad223b890aa16c5471f2ac3056cf76c5f10f82d6f9292f0b415f389000", size = 56641, upload-time = "2025-04-27T15:29:01.736Z" }
 wheels = [
@@ -2117,7 +2138,7 @@ wheels = [
 
 [[package]]
 name = "leann-backend-diskann"
-version = "0.3.2"
+version = "0.3.3"
 source = { editable = "packages/leann-backend-diskann" }
 dependencies = [
     { name = "leann-core" },
@@ -2129,14 +2150,14 @@ dependencies = [
 
 [package.metadata]
 requires-dist = [
-    { name = "leann-core", specifier = "==0.3.2" },
+    { name = "leann-core", specifier = "==0.3.3" },
     { name = "numpy" },
     { name = "protobuf", specifier = ">=3.19.0" },
 ]
 
 [[package]]
 name = "leann-backend-hnsw"
-version = "0.3.2"
+version = "0.3.3"
 source = { editable = "packages/leann-backend-hnsw" }
 dependencies = [
     { name = "leann-core" },
@@ -2149,7 +2170,7 @@ dependencies = [
 
 [package.metadata]
 requires-dist = [
-    { name = "leann-core", specifier = "==0.3.2" },
+    { name = "leann-core", specifier = "==0.3.3" },
     { name = "msgpack", specifier = ">=1.0.0" },
     { name = "numpy" },
     { name = "pyzmq", specifier = ">=23.0.0" },
@@ -2157,7 +2178,7 @@ requires-dist = [
 
 [[package]]
 name = "leann-core"
-version = "0.3.2"
+version = "0.3.3"
 source = { editable = "packages/leann-core" }
 dependencies = [
     { name = "accelerate" },
@@ -2297,7 +2318,7 @@ test = [
 
 [package.metadata]
 requires-dist = [
-    { name = "astchunk", specifier = ">=0.1.0" },
+    { name = "astchunk", editable = "packages/astchunk-leann" },
     { name = "beautifulsoup4", marker = "extra == 'documents'", specifier = ">=4.13.0" },
     { name = "black", marker = "extra == 'dev'", specifier = ">=23.0" },
     { name = "boto3" },