# stdio Transport Implementation Summary
## Overview
Successfully added stdio transport support to the MCP server, enabling CLI usage and integration with Claude Desktop and other MCP clients.
## Changes Made
### 1. Updated `src/index.ts`
- Added `--stdio` command-line flag detection
- Imported `StdioServerTransport` from MCP SDK
- Imported new `createStdioMcpServer` function
- Added conditional logic to start server in either HTTP/SSE or stdio mode
- stdio mode uses `console.error` for logs (keeps stdout clean for JSON-RPC)
- Graceful shutdown handling for both modes
### 2. Updated `src/server.ts`
- Added `StdioMcpServerContext` interface (without Express app)
- Created `createStdioMcpServer()` function for stdio-only initialization
- Simplified server setup without HTTP endpoints in stdio mode
### 3. Updated `src/tools/index.ts`
- Added import for `ListToolsRequestSchema` from MCP SDK
- Registered explicit handler for `tools/list` requests
- Required for low-level Server class (high-level McpServer does this automatically)
- Returns empty tools array (will be populated in Phase 2)
### 4. Updated `package.json`
- Added `start:stdio` script: `node dist/index.js --stdio`
### 5. Created Test Files
- `test-stdio.ts`: Automated test suite using TypeScript
- Tests initialize handshake
- Tests tools/list request
- Verifies JSON-RPC responses
- Full end-to-end validation
- `test-stdio-manual.sh`: Simple shell script for manual testing
- Quick verification with echo command
### 6. Updated `README.md`
- Added stdio Mode section with usage examples
- Documented both transport modes (HTTP/SSE and stdio)
- Added test script documentation
- Updated MCP Connection section
## Test Results
All tests passing:
```
ALL TESTS PASSED!
Initialize: PASS
Tools/list: PASS
```
## Usage
### Start in stdio mode:
```bash
npm run start:stdio
```
### Start in HTTP/SSE mode (default):
```bash
npm start
```
### Test stdio transport:
```bash
# Automated test
npx tsx test-stdio.ts
# Manual test
./test-stdio-manual.sh
# Echo test
echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"test","version":"1.0.0"}}}' | npm run start:stdio
```
## Technical Details
### stdio Transport
- Uses `StdioServerTransport` from `@modelcontextprotocol/sdk/server/stdio.js`
- Reads JSON-RPC requests from stdin (one per line)
- Writes JSON-RPC responses to stdout (one per line)
- Logs to stderr to keep stdout clean
### MCP Protocol Support
The server now properly handles:
- `initialize` request - Server handshake
- `initialized` notification - Initialization complete
- `tools/list` request - List available tools (returns empty array for now)
### Future Tool Registration
When tools are added in Phase 2+, update the `tools/list` handler in `src/tools/index.ts` to return the actual tool definitions instead of an empty array.
## Claude Desktop Integration
To use with Claude Desktop, add to your Claude Desktop config:
```json
{
"mcpServers": {
"mcp-anvil-tools": {
"command": "node",
"args": [
"/path/to/mcp-anvil-tools/dist/index.js",
"--stdio"
],
"env": {
"AUDIT_API_KEY": "your-api-key",
"MAINNET_RPC_URL": "your-rpc-url"
}
}
}
}
```
## Files Modified
- `src/index.ts`
- `src/server.ts`
- `src/tools/index.ts`
- `package.json`
- `README.md`
## Files Created
- `test-stdio.ts`
- `test-stdio-manual.sh`
- `STDIO-IMPLEMENTATION.md`
