I was referring the substrate documentation on preparing a local relay chain . The documentation has provided a sample plain chain spec with two validators Alice and Bob. I need to hardcode an additional validator. I think I need to add something like below in the keys array in the chain spec but I'm not exactly sure what would the values for beefy, granpa etc would be.

            "grandpa": "5GoNkf6WdbxCFnPdAnYYQyCjAKPJgLNxXwPjwTh6DGg6gN3E",
            "babe": "5FHneW46xGXgs5mUiveU4sbTyGBzmstUspZC92UhjJM694ty",
            "im_online": "5FHneW46xGXgs5mUiveU4sbTyGBzmstUspZC92UhjJM694ty",
            "para_validator": "5FHneW46xGXgs5mUiveU4sbTyGBzmstUspZC92UhjJM694ty",
            "para_assignment": "5FHneW46xGXgs5mUiveU4sbTyGBzmstUspZC92UhjJM694ty",
            "authority_discovery": "5FHneW46xGXgs5mUiveU4sbTyGBzmstUspZC92UhjJM694ty"

1 Answer 1


Within your chain_spec.rs file you can find the types for those keys.

In the linked example we have

initial_authorities: Vec<(AuraId, GrandpaId)>,

In you case you will just need to declare the type for each key that you are using.

Another example with more keys defined can be found here

/// Helper function to create RuntimeGenesisConfig for testing.
pub fn testnet_genesis(
    initial_authorities: Vec<(
    initial_nominators: Vec<AccountId>,
    root_key: AccountId,
    endowed_accounts: Option<Vec<AccountId>>,
) -> RuntimeGenesisConfig {
// snip
  • I am not sure if i understand this. I am referreing to the sample plain chain spec that has been provided in the documentation. I dont' think that this plain chainspec which is a json file is genereated from the node template for this specific example nor is the plain file generated from chain spec of the release i am using. Also i am not completely sure of what the type for keys would be .
    – RRR
    Commented Oct 31, 2023 at 11:47
  • I also checked the chain spec in the polkadot sdk. I think that in chain_spec.rs rococo_local_tesnet is configured for two validator and i would have to make some code changes to use one more validator.
    – RRR
    Commented Oct 31, 2023 at 12:13
  • And this is what they mean by hardcoding an additional validator and generating chainspec or i can use wococo since it is configured for more than two validators but then again i would need a wasm binary to generate the chainspec for wococo.
    – RRR
    Commented Oct 31, 2023 at 12:27

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