UPDATE: The election always finalizes with Election Fallback and set of validators doesnt't and neither does the Era, but sessions keep increasing. I understand that an era is just a couple of sessions after which Staking does reward/slashes, and having set the Session length, the proper ElectionDataProvider and ElectionProvider, I am unable to resolve the issue still.

I'm implementing a permissioned EVM compatible NPoS chain on the Frontier node template using Aura as my block producer.

I have implemented the necessary pallets(Staking, timestamp, session, GRANDPA(came pre implemented), evm/ethereum etc).

I've set 3 initial stakers/Aura authorities(Alice, Bob, Charlie) and expect to manually add more.

The chain works fine in local testnet, however this is an event that is emitted, indicating that election is not triggered. Can anyone suggest what the issue is?


Here is the configuration for my Staking, Session and Grandpa pallet.


enter image description here

  • You may want to link your repo here to expedite debugging.
    – Bruno
    Jul 27, 2022 at 13:48
  • Aura is PoA, not PoS, are you sure this is what you want instead of BABE? Jul 27, 2022 at 13:57
  • Yes, i chose Aura over Babe so didnt have to move the node to Babe as well. Jul 27, 2022 at 15:18
  • @BernardoRodrigues I've seen that Aura can be used for NPoS, and that triggering a sesison to end and election to start is pallet_session's job. I have configured all those together, im not sure where the issue is. Jul 28, 2022 at 6:30

1 Answer 1


What I understand from your question is that you want EVM compatibility in your chain, so the best option for that is to integrate EVM pallet to you chain instead of changing in frontier.

And also you want to implement NPoS using AURA which is quite a difficult task, as NPoS uses Phragmen Elections which depends on a weighted system and AURA does not have weighted implementation whereas BABE implement weights, you can check here.

If you want to go with AURA for block production than you need to implement weights in it and accordingly change GRANDPA to make it work properly.

I hope this helps.

  • Thank you! I went with Aura as I was unable to change my node to Babe in frontier. Can you share any example or a repository which I can follow to accomplish Having NPoS and EVM compatibility? One that may be closer to polkadot-v0.9.22 release? Aug 1, 2022 at 5:10

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