I had developed my all code based on CO order mechanism and suddenly Zerodha stop CO order type on F&O starting 1st September. Was there any circular before that mentioned that CO will be stopped starting 01-Sep? I am not sure the logic behind or technical dependency. If CO order is allowed for F&O then it is safe trading instead of putting open NRML order. Zerodha can block 100% margin on CO as per SEBI new rule. Now need to reinvent the wheel by writing CO mechanism in own code. Zerodha API should give backward compatibility every time they upgrade or change anything unless functionality stopped by authority. This is a reliability issue which API in case such thing happen frequently in future as well. I am with zerodha considering they are the most reliable one among all brokers who provide API for stability and support. Any one facing same problem?