maroo-assets

A tool that generates Blockscout explorer-ready JSON for precompile contracts deployed on Maroo Chain (EVM-compatible testnet).

Requirements

• Node.js (LTS recommended)
• pnpm

Installation

pnpm install

Usage

Generate precompile definition JSON:

pnpm run generate

Output file: output/precompiles-maroo.json
Raw URL for use with Blockscout (after pushing to GitHub):

https://raw.githubusercontent.com/<owner>/<repo>/<branch>/output/precompiles-maroo.json

(Replace <owner>, <repo>, and <branch> with your GitHub user/org, repository, and branch.)

Use this URL as the precompiles asset path in Blockscout settings so the explorer can read and decode each precompile’s ABI and source.

Precompile list

Name	Address	ABI/source
P256	0x0000000000000000000000000000000000000100	Defined in this repo (EIP-7212 / Cosmos EVM)
Bech32	0x0000000000000000000000000000000000000400	cosmos-evm-contracts
Staking	0x0000000000000000000000000000000000000800	cosmos-evm-contracts
Distribution	0x0000000000000000000000000000000000000801	cosmos-evm-contracts
Bank	0x0000000000000000000000000000000000000804	cosmos-evm-contracts
Gov	0x0000000000000000000000000000000000000805	cosmos-evm-contracts
Slashing	0x0000000000000000000000000000000000000806	cosmos-evm-contracts
OKRW	0x1000000000000000000000000000000000000001	maroo-contracts
PCL	0x1000000000000000000000000000000000000005	maroo-contracts

Adding new precompiles

When new precompiles are added to the chain, follow these steps.

1. Register address and name (src/config.ts)

• Add the address to PRECOMPILE_ADDRESSES as Name: "0x...".
• If the precompile comes from cosmos-evm-contracts → add the name to the COSMOS_EVM_NAMES array.
• If it comes from maroo-contracts → add the name to the MAROO_NAMES array.
• If it’s custom (not from either package) → add the name to COSMOS_EVM_NAMES and define ABI/source in a separate module (see step 2).

2. Wire ABI and source

• From cosmos-evm-contracts

  • In src/cosmos-evm.ts, import the module (e.g. abi/precompiles/<module>/<Interface>).
  • Add the name and paths to COSMOS_ABI_MAP and COSMOS_SOL_PATHS.
  • If the name is already in COSMOS_EVM_NAMES, it will be picked up automatically by collectCosmosEvmPrecompiles().

• From maroo-contracts

  • In src/maroo.ts, import the module (e.g. abi/precompiles/<module>/<Interface>).
  • Add the name and paths to MAROO_ABI_MAP and MAROO_SOL_PATHS.
  • collectMarooPrecompiles() iterates over MAROO_NAMES, so adding the name in step 1 is enough for it to be collected.

• Custom (precompile not in any package)

  • Create a new file under src/ (e.g. src/NewPrecompile.ts) and export the ABI array and Solidity source string.
  • In src/cosmos-evm.ts (or a dedicated collector), import that export and push an entry manually (similar to the P256 handling at the start of collectCosmosEvmPrecompiles()).

3. Generate and verify

pnpm run generate

Confirm the new precompile appears in output/precompiles-maroo.json, then add a row to the Precompile list table in this README (name, address, source).

Dependencies

• cosmos-evm-contracts — P256 (manual), Bech32, Staking, Distribution, Bank, Gov, Slashing interfaces/ABI
• maroo-contracts — OKRW, PCL interfaces/ABI