Fresh request_token returns Invalid checksum – direct API and Python SDK both fail

mamshankar

I have an active Kite Connect application with the paid Connect subscription.

Login through the Kite Connect login URL succeeds and generates a fresh request_token.

I have tested access-token generation using:

Official Python kiteconnect 5.2.1 SDK
Independent Python implementation using SHA-256(api_key + request_token + api_secret)
Direct POST to https://api.kite.trade/session/token

Both methods return:

HTTP 403

{"status":"error","message":"Invalid checksum.","data":null,"error_type":"TokenException"}

The request token is freshly generated immediately before the exchange.

The API secret has also been regenerated and retested.

Please check the API application's server-side authentication/session-token configuration.

I will provide the API key privately if required, but I will not post the API secret, request token or access token publicly.