lci MCP Server

The lci MCP server provides sub-millisecond semantic code search with intelligent context reduction, enabling codebase navigation and dependency understanding.

Installation

# Using npx (recommended)
npx @standardbeagle/lci@latest mcp

# Global installation
npm install -g @standardbeagle/lci
lci mcp

Configuration

Claude Code

{
  "mcpServers": {
    "lci": {
      "command": "npx",
      "args": ["-y", "@standardbeagle/lci@latest", "mcp"],
      "env": {
        "LCI_INDEX_PATH": ".lci-index"
      }
    }
  }
}

Environment Variables

Variable	Description	Default
LCI_INDEX_PATH	Path to index storage	.lci-index
LCI_EXCLUDE_PATTERNS	Patterns to exclude	node_modules,dist,build
LCI_MAX_FILE_SIZE	Max file size to index	1MB

Available Tools

Search

Tool	Description	Parameters
search	Semantic code search	query: string, limit?: number
search_by_type	Search by symbol type	type: string, query?: string
search_files	Search file names	pattern: string

Context

Tool	Description	Parameters
get_context	Get symbol context	symbol: string, depth?: number
get_definition	Get symbol definition	symbol: string
get_references	Find all references	symbol: string
get_callers	Find callers	symbol: string
get_callees	Find callees	symbol: string

Exploration

Tool	Description	Parameters
explore	Explore codebase structure	path?: string, depth?: number
list_symbols	List symbols in file	file: string
list_files	List files in directory	path?: string
get_file_info	Get file metadata	file: string

Index Management

Tool	Description	Parameters
index_status	Check index status	-
reindex	Rebuild the index	force?: boolean
add_to_index	Add files to index	paths: string[]

Usage Examples

Semantic Search

// Search for authentication logic
const results = await search({
  query: "user authentication login",
  limit: 10
});

console.log(results);
// Output: {
//   results: [
//     { file: "src/auth/login.ts", symbol: "authenticate", score: 0.95 },
//     { file: "src/middleware/auth.ts", symbol: "verifyToken", score: 0.87 }
//   ],
//   context_reduction: 0.79
// }

Get Symbol Context

// Get context for a function
const context = await get_context({
  symbol: "UserService.authenticate",
  depth: 2
});

console.log(context);
// Output: {
//   definition: "async authenticate(email: string, password: string): Promise<User>",
//   file: "src/services/UserService.ts",
//   line: 45,
//   callers: ["AuthController.login", "AuthMiddleware.verify"],
//   callees: ["hashPassword", "generateToken"],
//   documentation: "Authenticates a user by email and password..."
// }

Explore Structure

// Explore directory structure
const structure = await explore({
  path: "src/components",
  depth: 2
});

console.log(structure);
// Output: {
//   directories: [...],
//   files: [...],
//   symbol_count: 156,
//   types: { class: 12, function: 89, interface: 15 }
// }

Find References

// Find all references to a symbol
const refs = await get_references({
  symbol: "config"
});

console.log(refs);
// Output: {
//   references: [
//     { file: "src/index.ts", line: 5, context: "import { config } from..." },
//     { file: "src/api/server.ts", line: 12, context: "const port = config.port" }
//   ],
//   count: 23
// }

Index Building

The index is built automatically on first use. You can also trigger manually:

// Check index status
const status = await index_status();
// { indexed: true, files: 234, symbols: 1567, last_updated: "..." }

// Force reindex
await reindex({ force: true });

Supported Languages

Language	File Extensions	Features
TypeScript	.ts, .tsx	Full support
JavaScript	.js, .jsx	Full support
Python	.py	Full support
Go	.go	Full support
Rust	.rs	Full support
Java	.java	Partial support
C/C++	.c, .cpp, .h	Partial support

Response Format

All tools return responses in this format:

{
  "success": true,
  "data": { ... },
  "metadata": {
    "query_time_ms": 0.5,
    "context_reduction": 0.79
  }
}

Performance

Operation	Typical Time
Search	<1ms
Get context	<2ms
Explore	<5ms
Reindex	~100ms per 1000 files

Context Reduction

lci achieves 79.8% context reduction by:

1. Symbol extraction: Only relevant symbols
2. Relationship filtering: Related code only
3. Documentation prioritization: Comments and docs first
4. Noise elimination: Exclude boilerplate

Error Codes

Code	Description
INDEX_NOT_READY	Index not yet built
SYMBOL_NOT_FOUND	Symbol doesn't exist
FILE_NOT_FOUND	File doesn't exist
PARSE_ERROR	Failed to parse file

Version History

Version	Changes
0.3.0	Cross-platform improvements
0.2.0	Added more languages
0.1.0	Initial release

Related Resources

• lci Plugin
• NPM Package
• GitHub Repository