Configuring Chain ID

Fetching your Chain ID:

The default chain ID on Madara is SN_GOERLI, to verify your chain ID, a POST call can be made to the RPC endpoint.

Initiate RPC Request:

Execute the following POST request via curl to query the chain ID from your Madara node.
Endpoint: http://localhost:9944 (opens in a new tab) (replace with the appropriate remote URL).

    curl --location 'http://localhost:9944' \
    --header 'Content-Type: application/json' \
    --data '{
        "id": 0,
        "jsonrpc": "2.0",
        "method": "starknet_chainId",
        "params": {}
    }'

Parse Response:

Extract the chain ID in hex format from the "result" field within the JSON response.

    {
        "jsonrpc": "2.0",
        "result": "0x534e5f474f45524c49",
        "id": 0
    }

Translate Hex:

Use a hex converter tool (e.g., https://stark-utils.vercel.app/converter (opens in a new tab)) to obtain the readable string representation of the chain ID.

Setting a custom Chain ID:

The Chain ID for your Madara app chain is configured in crates/runtime/src/pallets.rs. In Madara your chain ID is represented as the montgomery representation for a string. To update this follow the below steps;

Define your Chain ID:

Choose a string to represent your app chain.

Convert Chain ID to felt

Navigate to https://stark-utils.vercel.app/converter and input your chosen string. The generated felt value is your hexadecimal representation for the string. stack

Generate montgomery representation:

Use Starkli to convert the felt value to a montgomery representation compatible with Madara.

starkli mont 85046245544016
[
    18444022593852143105,
    18446744073709551615,
    18446744073709551615,
    530195594727478800,
]

Update the Chain ID:

Open crates/primitives/chain-id/src/lib.rs and add your Chain ID alongside existing definitions:

pub const MY_APP_CHAIN_ID: Felt252Wrapper = Felt252Wrapper(starknet_ff::FieldElement::from_mont([
    18444025906882525153,
    18446744073709551615,
    18446744073709551615,
    530251916243973616,
]));

Update `pallets.rs`:

Modify the import statement in crates/runtime/src/pallets.rs to include your new Chain ID definition (refer to https://github.com/keep-starknet-strange/madara/blob/main/crates/runtime/src/pallets.rs#L13 (opens in a new tab) for reference).
Update the usage of the Chain ID within the code itself (refer to https://github.com/keep-starknet-strange/madara/blob/main/crates/runtime/src/pallets.rs#L164 (opens in a new tab) for reference).

Rebuild your Madara app chain with the updated pallets.rs file. Your app chain will now operate with your custom Chain ID.

Protocol Configuration Madara with the --dev flag