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fix: Port Discovery Protocol Mismatch #341

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Merged
merged 1 commit into from
Oct 23, 2025
Merged

fix: Port Discovery Protocol Mismatch #341

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6 changes: 3 additions & 3 deletions MCPForUnity/UnityMcpServer~/src/port_discovery.py
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Original file line number Diff line number Diff line change
Expand Up @@ -56,16 +56,16 @@ def list_candidate_files() -> List[Path]:
@staticmethod
def _try_probe_unity_mcp(port: int) -> bool:
"""Quickly check if a MCP for Unity listener is on this port.
Tries a short TCP connect, sends 'ping', expects a JSON 'pong'.
Tries a short TCP connect, sends 'ping', expects Unity bridge welcome message.
"""
try:
with socket.create_connection(("127.0.0.1", port), PortDiscovery.CONNECT_TIMEOUT) as s:
s.settimeout(PortDiscovery.CONNECT_TIMEOUT)
try:
s.sendall(b"ping")
data = s.recv(512)
# Minimal validation: look for a success pong response
if data and b'"message":"pong"' in data:
# Check for Unity bridge welcome message format
if data and (b"WELCOME UNITY-MCP" in data or b'"message":"pong"' in data):
return True
except Exception:
return False
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