A lightweight, zero-overhead implementation of the Model Context Protocol (MCP) server in pure Bash.
Why? Most MCP servers are just API wrappers with schema conversion. This implementation provides a zero-overhead alternative to Node.js, Python, or other heavy runtimes.
- ✅ Full JSON-RPC 2.0 protocol over stdio
- ✅ Complete MCP protocol implementation
- ✅ Dynamic tool discovery via function naming convention
- ✅ External configuration via JSON files
- ✅ Easy to extend with custom tools
- Bash shell
- jq for JSON processing (brew install jq on macOS)
- Clone the repo
git clone https://github.com/muthuishere/mcp-server-bash-sdk
cd mcp-server-bash-sdk
- Make scripts executable
chmod +x mcpserver_core.sh moviemcpserver.sh
- Try it out
echo '{"jsonrpc": "2.0", "method": "tools/call", "params": {"name": "get_movies"}, "id": 1}' | ./moviemcpserver.sh
┌─────────────┐ ┌────────────────────────┐
│ MCP Host │ │ MCP Server │
│ (AI System) │◄──────► │ (moviemcpserver.sh) │
└─────────────┘ stdio └────────────────────────┘
│
┌───────┴──────────┐
▼ ▼
┌─────────────────┐ ┌───────────────┐
│ Protocol Layer │ │ Business Logic│
│(mcpserver_core.sh)│ │(tool_* funcs)│
└─────────────────┘ └───────────────┘
│ │
▼ ▼
┌─────────────────┐ ┌───────────────┐
│ Configuration │ │ External │
│ (JSON Files) │ │ Services/APIs │
└─────────────────┘ └───────────────┘
- mcpserver_core.sh: Handles JSON-RPC and MCP protocol
- moviemcpserver.sh: Contains business logic functions
- assets/: JSON configuration files
- Create your business logic file (e.g., weatherserver.sh)
#!/bin/bash
# Weather API implementation
# Source the core MCP server
source "$(dirname "${BASH_SOURCE[0]}")/mcpserver_core.sh"
# Access environment variables
API_KEY="${MCP_API_KEY:-default_key}"
# Weather tool implementation
tool_get_weather() {
local args="$1"
local location=$(echo "$args" | jq -r '.location')
# Call external API
local weather=$(curl -s "https://api.example.com/weather?location=$location&apikey=$API_KEY")
echo "$weather"
return 0
}
# Forecast tool implementation
tool_get_forecast() {
local args="$1"
local location=$(echo "$args" | jq -r '.location')
local days=$(echo "$args" | jq -r '.days')
local forecast=$(curl -s "https://api.example.com/forecast?location=$location&days=$days&apikey=$API_KEY")
echo "$forecast"
return 0
}
# Start the MCP server
run_mcp_server "$@"
- Create tools_list.json in the assets directory
{
"tools": [
{
"name": "get_weather",
"description": "Get current weather for a location",
"parameters": {
"type": "object",
"properties": {
"location": {
"type": "string",
"description": "City name or coordinates"
}
},
"required": ["location"]
}
},
{
"name": "get_forecast",
"description": "Get weather forecast for multiple days",
"parameters": {
"type": "object",
"properties": {
"location": {
"type": "string",
"description": "City name or coordinates"
},
"days": {
"type": "integer",
"description": "Number of days to forecast"
}
},
"required": ["location", "days"]
}
}
]
}
- Update mcpserverconfig.json
{
"protocolVersion": "0.1.0",
"serverInfo": {
"name": "WeatherServer",
"version": "1.0.0"
},
"capabilities": {
"tools": {
"listChanged": true
}
},
"instructions": "This server provides weather information and forecasts."
}
- Make your file executable
chmod +x weatherserver.sh
- Update VS Code settings.json
- Use with GitHub Copilot Chat
/mcp my-weather-server get weather for New York
- No concurrency/parallel processing
- Limited memory management
- No streaming responses
- Not designed for high throughput
For AI assistants and local tool execution, these aren't blocking issues.
This project is licensed under the MIT License - see the LICENSE file for details.
The complete code is available at: https://github.com/muthuishere/mcp-server-bash-sdk
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