"""Reads JSON-encoded string from stdin (the kind MCP returns when wrapping a string),
and writes the decoded value as UTF-8 to the given file."""
import json, sys, os
out_path = sys.argv[1]
raw = sys.stdin.read()
# raw is a JSON string like "[{\"name\":\"...\"}]"  — already JSON-quoted
decoded = json.loads(raw)
os.makedirs(os.path.dirname(out_path) or '.', exist_ok=True)
with open(out_path, 'w', encoding='utf-8') as f:
    f.write(decoded)
print(f'wrote {out_path} ({len(decoded)} chars)')