"""Binary-mode MCP server - exact byte control"""
import sys
import os
import json
def log(msg):
sys.stderr.write(f"[BIN] {msg}\n")
sys.stderr.flush()
# Switch stdout to binary mode on Windows
if sys.platform == 'win32':
import msvcrt
msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)
# Get binary streams
stdin_bin = sys.stdin.buffer
stdout_bin = sys.stdout.buffer
def read_line():
"""Read a line from binary stdin"""
line = b''
while True:
ch = stdin_bin.read(1)
if not ch:
return None
if ch == b'\n':
break
if ch != b'\r': # Skip carriage return
line += ch
return line.decode('utf-8') if line else None
def write_response(msg):
"""Write JSON response as exact bytes"""
body = json.dumps(msg, separators=(',', ':'))
data = body.encode('utf-8') + b'\n'
log(f"Writing {len(data)} bytes: {data[:80]}")
stdout_bin.write(data)
stdout_bin.flush()
log("=== Binary MCP Server ===")
# Initialize
log("Waiting for initialize...")
line = read_line()
log(f"Got line: {line[:100] if line else 'None'}")
if line:
request = json.loads(line)
if request.get('method') == 'initialize':
write_response({
"jsonrpc": "2.0",
"id": request.get("id"),
"result": {
"protocolVersion": "2024-11-05",
"capabilities": {"tools": {}},
"serverInfo": {"name": "binary-test", "version": "1.0.0"}
}
})
log("Waiting for initialized...")
line = read_line()
log(f"Got: {line[:100] if line else 'None'}")
log("Main loop...")
while True:
line = read_line()
if not line:
log("EOF")
break
msg = json.loads(line)
log(f"Got: {json.dumps(msg)[:80]}")
method = msg.get('method', '')
msg_id = msg.get('id')
if method == 'tools/list':
write_response({
"jsonrpc": "2.0",
"id": msg_id,
"result": {
"tools": [{
"name": "hello",
"description": "Say hello",
"inputSchema": {
"type": "object",
"properties": {"name": {"type": "string"}},
"required": ["name"]
}
}]
}
})
elif method == 'tools/call':
name = msg.get('params', {}).get('arguments', {}).get('name', 'World')
write_response({
"jsonrpc": "2.0",
"id": msg_id,
"result": {
"content": [{"type": "text", "text": f"Hello, {name}!"}]
}
})
log("=== Done ===")
