Not able to get 2 optionchain data for different expiries at once

APIs, Automation, Algos & Code
1

I’m trying to get the option chain data of 2 different expiry and I get the “429 too many requests” error. Why is the 3 second rate limiting applied for different expiry?
I’m aware of the rate limiting - 5 reqs/s for data APIs and for option chain API, it is 1 req per 3 sec (because OI data gets updated slow) as per docs.
If the intention is to rate limit because data updates are slow, allow to fetch other expiry data within the global data API rate limit of 5 reqs/s. The current one doesn’t even allow 2!?

Am I doing this wrong or it is what it is? Is there any workaround?

Code:

async def fetch_oc_data(db, client, instrument):
    expiries = await fetch_expiries(client, instrument)
    print(f"Got {len(expiries)} expiries for {instrument['SECURITY_ID']}")

    for i, expiry in enumerate(expiries):
        try:
            print(f"Fetching {instrument['SECURITY_ID']} {expiry} ({i+1}/{len(expiries)})")

            oc, last_price = await fetch_chain_for_expiry(client, instrument, expiry)
            store_oc_data(db, instrument, expiry, oc)
            
            print(f"Successfully stored {instrument['SECURITY_ID']} {expiry}")
                
        except Exception as e:
            print(f"Error fetching {instrument['SECURITY_ID']} {expiry}: {e}")
            continue

    db.commit()
    print("added all expiry oc data to db")

Console:

Got 18 expiries for NIFTY
Fetching NIFTY 2025-06-19 (1/18)
Successfully stored NIFTY 2025-06-19
Fetching NIFTY 2025-06-26 (2/18)
Error fetching NIFTY 2025-06-26: Client error '429 Too Many Requests' for url 'https://api.dhan.co/v2/optionchain'
Fetching NIFTY 2025-07-03 (3/18)
Error fetching NIFTY 2025-07-03: Client error '429 Too Many Requests' for url 'https://api.dhan.co/v2/optionchain'
Fetching NIFTY 2025-07-10 (4/18)
Error fetching NIFTY 2025-07-10: Client error '429 Too Many Requests' for url 'https://api.dhan.co/v2/optionchain'
2

bhai try 30 seconds interval between two charts make if you fetch data her at 9:15;30 fetch their at 9:15: 45 here first one at 9:16, second one at 9:16:15 may be it will work i tried once but i am using one chain only now but i tried in past it worked time them with gap

3

say, i’m displaying 6 expiry’s data. then for all the data to be refreshed, it would take 3 mins if i do it with 1 request per 30 sec. if the normal data API’s rate limit applied here, it would be updated in a couple of seconds. i think it is a huge difference

4

for six option chain :joy: don’t expect option chain data api it will definitely crash with message limit exceed . Its better go with dhan web option chain provided in the broker website. I tried different approach but succeeded up to two option chain and later felt confused with more data now restricted to one option chain .