# checksum error in python login

**URL:** https://tradingqna.com/t/checksum-error-in-python-login/197878
**Category:** F&O
**Created:** [September 8, 2026, 3:41am UTC](https://tradingqna.com/t/checksum-error-in-python-login/197878 "2026-09-08T03:41:03Z")
**Posts on this page:** 2
**Page:** 1

<div class="post-metadata">

### Author: ![Bajarang\_Kumar](https://tradingqna.com/user_avatar/tradingqna.com/bajarang_kumar/32/74248_2.png) [@Bajarang\_Kumar](https://tradingqna.com/u/Bajarang_Kumar)
#### Post date: [September 8, 2026, 3:41am UTC](https://tradingqna.com/t/checksum-error-in-python-login/197878/1 "2026-09-08T03:41:03Z")

</div>

**Kite Connect authentication issue — persistent Invalid checksum**

App type: Connect  
App status: Active  
Kite Connect subscription: Valid  
API key: 16 characters  
API secret: 32 characters  
Python SDK: official KiteConnect  
Fresh request token: 32 characters  
Checksum: SHA256(api\_key + request\_token + api\_secret)  
generate\_session() returns: TokenException: Invalid ‘checksum’

I tested this using a standalone script with the API key and API secret entered directly from the active Connect application, independent of my trading application. The login succeeds and produces a fresh request token, but /session/token rejects it with Invalid checksum.

Please verify whether there is an account/application-side issue with session-token generation for this Connect app.

---

<div class="post-metadata">

### Author: ![Sravanthi\_Bh](https://tradingqna.com/user_avatar/tradingqna.com/sravanthi_bh/32/23189_2.png) [@Sravanthi\_Bh](https://tradingqna.com/u/Sravanthi_Bh)
#### Post date: [September 8, 2026, 7:22am UTC](https://tradingqna.com/t/checksum-error-in-python-login/197878/4 "2026-09-08T07:22:33Z")

</div>

> [@Bajarang\_Kumar](#):
>
> **Kite Connect authentication issue — persistent Invalid checksum**

The `Invalid checksum` error generally indicates that the `api_key`, `api_secret`, or `request_token` being used for the token exchange does not match.

We have verified this at our end and there is no issue with the APIs.

Please try generating a fresh `request_token` and exchanging it for an `access_token` immediately, since the request token is short-lived and can be used only once.

Also, please ensure that you are following the [login flow](https://kite.trade/docs/connect/v3/user/)exactly as outlined in the Kite Connect API documentation.

You may also refer to this [similar discussion on the Kite Connect forum](https://kite.trade/forum/discussion/2005/invalid-checksum)