Change in I1 1-Minute Candle Update Behavior in WebSocket Feed

Developer API
1

I would like to bring to your attention a recent change in the behavior of the I1 (1-minute) candles in the WebSocket live feed, specifically observed for instruments like NSE_INDEX|Nifty 50.

Earlier behavior (expected):

  • At the beginning of a new 1-minute interval (e.g., 09:15), the I1 candle would be generated with the first tick.
  • This candle remained dynamic until the minute was completed and finalized (only for 9:15), and the subsequent minute would have the same candle until a new candle was finalized, making all other minute candle update static which would happen only after that candle was completed.

Current behavior (observed):

  • The I1 candle is now being updated with every tick, even before the current 1-minute interval has ended for all candles.
  • This dynamic update is resulting in multiple interim versions of the same candle during the minute, which appears to be a shift from the previous model where candles were finalized only after the interval ended.

Could you please confirm, is this related to the feed incident that occurred today or :

  1. Whether this change is intentional and applicable to all instruments?
  2. If this is now the standard candle behavior going forward?
  3. Why this change wasn’t communicated beforehand, and if we can expect changelogs or release notes for such critical updates in the future?
2

Hi @Raghav_35590666

The details on this is already mentioned in the documentation for the V3 sockets.

You can also know more here:Issue with Missing Current 1-Min Candle in Market Data Feed V3 - #22 by MohitGolecha

3

Hi @MohitGolecha, as you said we have the N-1 candle stable for the last minute while the current one is forming, that is my understanding of the V3 as well, it seemed to me that due to today’s incident what I observed was this behavior was also affected and we were getting still forming candle.

I Also Trade at the close and my program also expects a stable 1 min candle to be formed before taking a trade so this approach works well and so was pointing out that it happened today

4

Correct @Raghav_35590666

Today’s issue might have caused a momentary disruption. Let’s check things again tomorrow, it should be working fine!

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5

Here are two ticks that were recieved today:

"I1", "open": 24464.2, "high": 24516.1, "low": 24460.05, "close": 24501.7, "ts": "1754538300000"}]}}}, "requestMode": "full_d5"}}, "currentTs": "1754538359712"}

currentTs: 1754538359712 - Thursday, August 7, 2025 9:15:59.712 AM

And just after this as expected the next tick also should be the same because at the end of the 15th minute, the candle is finalized and is sent for the next minute until the 16th minute is finalized. But in todays error this was not the actual case:

{"interval": "I1", "open": 24498.35, "high": 24498.35, "low": 24498.35, "close": 24498.35, "ts": "1754538360000"}]}}}, "requestMode": "full_d5"}}, "currentTs": "1754538360162"}

currentTs: 1754538360162 - Thursday, August 7, 2025 9:16:00.162 AM

The I1 candle is being updated immediately at the start of the next minute, with values changing based on the first tick of the new minute, not retaining the previous minute’s finalized candle, as expected.

Yeah, I hope this gets resolved tomorrow and was due to the incident which occurred today.

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