I'd like to use the Polkadot CLI to create a chainspec with specific user balances pre-seeded. I'd like to be able to do this for any of the dev runtimes.

In the case of the polkadot dev runtime, I run polkadot build-spec --dev. In the case of others, I run polkadot build-spec --chain=<runtime-name-here>-local. I capture the output in a file, and then overwrite its genesis.runtime.balances.balances with a list of [ss58, amount] tuples.

Then I write the updated chainspec to my fs, and run it with polkadot --chain <path-to-spec>. In the case of Westend, I'm able to retrieve a test user balance. All others fail. Also, westend txs stall.

  • Hi Harry, are you getting the raw version after you update the genesis file?
    – pepoviola
    Jan 29, 2023 at 20:53
  • For future readers: we attempted to create a raw version from the edited, and still ran into the same issue. Will follow up if/when it's resolved. Feb 5, 2023 at 21:04

1 Answer 1


Achieved in Capi's devnet spawning logic like so.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.