I am using following link to run polkadot relay chain and connect substrate parachain node with it as parachain.


I downloaded the plain chain spece from following link as described in above toturial:


When I run following command convert plain change config to raw chain config. It gives error:enter image description here

./target/release/polkadot build-spec --chain plain-local-chainspec.json --raw --disable-default-bootnode > raw-local-chainspec.json

Error: 0: Other: Error parsing spec file: invalid type: null, expected struct GenesisConfig at line 84 column 34

I tested against following versions of polkadot: v0.9.29 v0.9.32

1 Answer 1


For the plain-local-chainspec.json you got in the tutorial, you can also download its raw chain specification file, so no need to generate it.

From the Polkadot repository where you are trying to generate the chain config, there is already a list of chain specs: https://github.com/paritytech/polkadot/tree/master/node/service/chain-specs

So in case you want to run the rococo local:

./target/release/polkadot --chain=rococo-local

And if you want to get the chain spec file from there:

./target/release/polkadot build-spec --chain rococo-local > rococo-chain-spec.json

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