Local Hardhat

Run a local EVM node, deploy Carbonized to it and point the web app at chain id 31337.

Use a local chain for fast iteration with no faucet or RPC limits.

Local network settings

Hardhat defaults:

Item	Value
Chain id	`31337`
RPC	`http://127.0.0.1:8545`
Accounts	20, each with 10,000 ETH (`hardhat` network)
Contract size	`allowUnlimitedContractSize: true` on `hardhat` and `localhost`, so the oversized `CarbonCreditNFT` deploys

Start a node

In your Hardhat project:

npx hardhat node

Deploy

In a second terminal:

Run your deployment script against the localhost network:

npx hardhat run <deploy-script> --network localhost

The script deploys the same set as the Robinhood deploy: NFT, three CCTs, a mock payment token (MockERC20, deployed with 18 decimals by the script; 100,000 minted to each of the first 10 accounts; the marketplace reads whatever decimals() the token has, 2 to 18), marketplace (Verra CCT), MockFunctionsRouter, EmissionVerifier, RegistrySync, CarbonPriceOracle. It grants NATIVE_ISSUER_ROLE to the verifier and deployer, WRAPPER_ROLE and KYC_ROLE to the deployer, and the deployer issues test credits with mintCredit to accounts 1 to 5 so they can wrap and sell. There is no faucet or starter-credit function. Deploy CarbonRegistry(admin) separately if you want the Company and Trader pages (it needs no role on the NFT).

Configure the web app

NEXT_PUBLIC_NETWORK=hardhat
NEXT_PUBLIC_CHAIN_ID=31337
NEXT_PUBLIC_RPC_URL=http://127.0.0.1:8545

When NEXT_PUBLIC_NETWORK=hardhat (or the chain id is 31337) and a contract address variable is unset, the app falls back to Hardhat's deterministic addresses for a fresh node and deployer account 0:

Contract	Fallback address
`CarbonCreditNFT`	`0x5FbDB2315678afecb367f032d93F642f64180aa3`
`CarbonCreditToken` (Verra)	`0x9fE46736679d2D9a65F0992F2272dE9f3c7fa6e0`
`CarbonMarketplace`	`0x0165878A594ca255338adfa4d48449f69242Eb8F`
`CarbonPriceOracle`	`0x610178dA211FEF7D417bC0e6FeD39F05609AD788`
`EmissionVerifier`	`0x2279B7A0a67DB372996a5FaB50D91eAA73d2eBe6`
Mock payment token	`0xDc64a140Aa3E981100a9becA4E685f962f0cF6C9`

If you deploy more than once on the same node, or from another account, addresses differ; set the NEXT_PUBLIC_* variables explicitly.

Connect a wallet

Add the local network to your wallet (RPC http://127.0.0.1:8545, chain id 31337, currency ETH) and import one of the node's printed development accounts. Those keys are public; never use them anywhere else.

Tests

npx hardhat test

Wallet connection through Reown AppKit still needs NEXT_PUBLIC_REOWN_PROJECT_ID. See Reown AppKit; injected wallets work on the local chain.