cherry-db-manager

Cherry DB Manager

A Rust library for managing Cherry Studio LevelDB configurations, specifically designed for handling MCP (Model Context Protocol) server configurations.

Overview

Cherry Studio stores its configuration data in LevelDB with a unique encoding format (UTF-16 LE with JSON strings). This library provides a clean, safe interface to read and modify MCP server configurations without dealing with the underlying complexity.

Features

• 🔧 Easy MCP Server Management - Read, write, add, and remove MCP servers
• 🛡️ Type-Safe - Full Rust type safety with serde serialization
• 📦 JSON-Friendly - All request/response structures are JSON-serializable
• ⚡ Performance-Focused - Direct LevelDB access with minimal overhead
• 🔐 Error Handling - Comprehensive error types for better debugging

Installation

Add this to your Cargo.toml:

[dependencies]
cherry-db-manager = "0.1.0"

Quick Start

use cherry_db_manager::{CherryDbManager, DefaultCherryDbManager, ServerRequest};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let manager = DefaultCherryDbManager::new();
    let db_path = "./path/to/cherry/studio/leveldb";

    // Read current server configuration
    let config = manager.read_mcp_config(db_path)?;
    println!("Found {} MCP servers", config.servers.len());

    // List all servers
    let servers = manager.list_servers(db_path)?;
    for server in servers.servers {
        println!("Server: {} ({})", server.id, server.name);
    }

    // Add a new server
    let new_server = ServerRequest {
        id: "my-server".to_string(),
        is_active: true,
        args: vec!["--config".to_string(), "config.json".to_string()],
        command: "node".to_string(),
        server_type: "stdio".to_string(),
        name: "My Custom Server".to_string(),
    };
    manager.add_server(db_path, &new_server)?;

    Ok(())
}

API Reference

Core Trait: CherryDbManager

pub trait CherryDbManager {
    fn read_mcp_config(&self, db_path: &str) -> Result<McpConfigResponse>;
    fn write_mcp_config(&self, db_path: &str, config: &McpConfigRequest) -> Result<()>;
    fn list_servers(&self, db_path: &str) -> Result<ServerListResponse>;
    fn add_server(&self, db_path: &str, server: &ServerRequest) -> Result<()>;
    fn remove_server(&self, db_path: &str, server_id: &str) -> Result<()>;
    fn server_exists(&self, db_path: &str, server_id: &str) -> Result<bool>;
}

Key Types

• ServerRequest / ServerResponse - MCP server configuration
• McpConfigRequest / McpConfigResponse - MCP server list
• ServerListResponse - Server listing with metadata
• CherryDbError - Comprehensive error types

Integration Guide

For Existing Projects

To minimize impact on your main project, use feature flags:

In your Cargo.toml:

[dependencies]
cherry-db-manager = { version = "0.1.0", optional = true }

[features]
cherry-integration = ["cherry-db-manager"]

In your code:

#[cfg(feature = "cherry-integration")]
mod cherry_integration {
    use cherry_db_manager::*;

    pub fn sync_mcp_servers(db_path: &str) -> Result<Vec<String>, Box<dyn std::error::Error>> {
        let manager = DefaultCherryDbManager::new();
        let servers = manager.list_servers(db_path)?;
        Ok(servers.servers.into_iter().map(|s| s.id).collect())
    }
}

Error Handling

use cherry_db_manager::{CherryDbError, Result};

match manager.read_mcp_config(db_path) {
    Ok(config) => println!("Success: {} servers", config.servers.len()),
    Err(CherryDbError::ConfigNotFound) => println!("No MCP config found"),
    Err(CherryDbError::InvalidPath(path)) => println!("Invalid path: {}", path),
    Err(CherryDbError::DatabaseError(msg)) => println!("DB error: {}", msg),
    Err(e) => println!("Other error: {}", e),
}

Data Format Details

Cherry Studio uses a unique storage format:

• LevelDB for fast key-value storage
• UTF-16 LE encoding with a header byte (0x00)
• Nested JSON strings for modular configuration

The MCP configuration is stored as a JSON string under the mcp key in the main configuration object.

Examples

Run the included example:

cargo run --example basic_usage

Development

This library is designed to be:

• Minimal - No unnecessary dependencies
• Safe - No unwrap() or expect() in public APIs
• Testable - Clear separation between I/O and logic
• Maintainable - Well-documented and structured

License

MIT License - see LICENSE for details.

Contributing

Issues and pull requests welcome! Please ensure all tests pass and follow the existing code style.