Environment variables

The environment variables the Carbonized web app reads, with placeholder values.

Web app (`.env.local`)

Onchain configuration

Variable	Required	Description
`NEXT_PUBLIC_NETWORK`	yes	`robinhood-mainnet` (chain id `4663`), `robinhood` (testnet, `46630`; alias `robinhood-testnet`), `hardhat`, `polygon`, `amoy` (alias `mumbai`) or anything else for Sepolia. Default: `hardhat` in development, `sepolia` otherwise. Any value other than `robinhood-mainnet` shows the red/amber "Testnet / unaudited" banner on the landing page and in the app.
`NEXT_PUBLIC_CHAIN_ID`	recommended	Chain id. Used as the chain id for contract config; `31337` triggers Hardhat address fallbacks.
`NEXT_PUBLIC_RPC_URL`	recommended	HTTP RPC for the target chain. Falls back to the chain's default (Hardhat: `http://127.0.0.1:8545`).
`NEXT_PUBLIC_LOGS_RPC_URL`	optional	RPC used for `eth_getLogs` history scans. Defaults to `https://robinhood-rpc.publicnode.com` for chain `4663` and `https://robinhood-sepolia-rpc.publicnode.com` for chain `46630`. Set it when `NEXT_PUBLIC_RPC_URL` is a plan that caps log ranges.
`NEXT_PUBLIC_EXPLORER_URL`	optional	Block explorer base URL used for transaction and address links. Defaults: `https://robinhoodchain.blockscout.com` (mainnet), `https://explorer.testnet.chain.robinhood.com` (testnet).
`NEXT_PUBLIC_CARBON_CREDIT_NFT`	yes	`CarbonCreditNFT` address
`NEXT_PUBLIC_CARBON_CREDIT_TOKEN`	yes	`CarbonCreditToken` for the marketplace's methodology (Verra in the testnet deployment)
`NEXT_PUBLIC_CARBON_MARKETPLACE`	yes	`CarbonMarketplace` address
`NEXT_PUBLIC_CARBON_PRICE_ORACLE`	yes	`CarbonPriceOracle` address
`NEXT_PUBLIC_EMISSION_VERIFIER`	yes	`EmissionVerifier` address
`NEXT_PUBLIC_payment token_ADDRESS`	yes	Payment token address: real payment token (6 decimals) on mainnet, mock payment token on testnet. The app reads `decimals()` of this address once and never assumes 18. It must be the same token the marketplace was deployed with.
`NEXT_PUBLIC_CARBON_REGISTRY`	yes	`CarbonRegistry` address: company/trader profiles, emissions and KYB. Without it the Company and Trader pages show a "Registry not configured" state.
`NEXT_PUBLIC_DEPLOY_BLOCK`	recommended	First block to scan when rebuilding history from event logs (emissions timeline, activity feeds, portfolio events). If unset the app scans only the last 20,000 blocks.
`NEXT_PUBLIC_CARBON_CREDIT_TOKEN_GOLD_STANDARD`, `NEXT_PUBLIC_CARBON_CREDIT_TOKEN_ICM_COMPLIANCE`	optional	`CarbonCreditToken` addresses for the other two methodology pools (used by pages that show all pools).

A missing or zero address shows a banner in the app shell listing the unset variables.

All five are optional and are not listed as missing in the app banner. When they are unset, the Token and Governance pages and the Issuer Bond panel show a "CARB is not live yet" state. CARB is not launched yet; see the CARB section.

Variable	Required	Description
`NEXT_PUBLIC_CARB_TOKEN`	optional	CARB token address: Carbonized's own `CarbToken` or an external (launchpad) token. Symbol and decimals are read from the contract.
`NEXT_PUBLIC_CARB_EXTERNAL`	optional	`true` when CARB is an external token: shows the External token info line. Written by `update-carb-env.js`.
`NEXT_PUBLIC_CARB_VOTES`	optional	`CarbVotes` voting wrapper (vCARB) for an external CARB without votes. When set, governance needs CARB deposited here and delegated.
`NEXT_PUBLIC_CARB_STAKING`	optional	`CarbStaking` address (tier, stake, unstake, withdraw). Also enables the fee-tier info line on the Sell Credits and Marketplace pages.
`NEXT_PUBLIC_ISSUER_BOND`	optional	`IssuerBond` address. Shows the Bond panel on the Issuer page.
`NEXT_PUBLIC_GOVERNOR`	optional	`CarbGovernor` address (proposals, votes).
`NEXT_PUBLIC_TIMELOCK`	optional	`CarbTimelock` address (queue and execute).

Wallet, contact and backend

Variable	Required	Description
`NEXT_PUBLIC_REOWN_PROJECT_ID`	for WalletConnect	Project id from `https://dashboard.reown.com`. See Reown AppKit.
`NEXT_PUBLIC_CONTACT_EMAIL`	optional	Contact email shown in the app and on the legal pages.
`NEXT_PUBLIC_BACKEND_URL`	optional, leave empty by default	Base URL of an off-chain depository backend. Registration, profiles and emissions come from the onchain registry, so the app works without a backend. Only set it if you run such a backend yourself: when it is set, the company registration flow sends the registration details, including email and phone, to that server. Its origin is added to the Content-Security-Policy automatically.

Site and platform

Variable	Description
`NEXT_PUBLIC_APP_URL`	Optional public URL of the site. When unset, production builds use the Vercel-provided domain (`VERCEL_PROJECT_PRODUCTION_URL`, then `VERCEL_URL`).
`SKIP_ENV_VALIDATION`	Set to any value to skip environment validation. Not needed for a normal deployment.
`NEXT_PUBLIC_UMAMI_URL`, `NEXT_PUBLIC_UMAMI_WEBSITE_ID`	Optional analytics

Restart after changes

NEXT_PUBLIC_* values are inlined by Next.js. Restart pnpm dev after editing .env.local.

Security headers and CSP

Security headers and a Content-Security-Policy are set in next.config.ts. Custom RPC, explorer, backend and analytics origins are added to the CSP automatically from the NEXT_PUBLIC_* URLs above, so you do not edit the policy by hand.

Optional: accounts and comments

The site deploys with only the NEXT_PUBLIC_* variables above. Sign-in with Google and blog comments switch on automatically once all of the following server-only variables are set (otherwise the UI shows "Comments are not enabled yet" and /api/auth and /api/comments answer 503). Set them in your hosting provider's secret store; never expose them to the browser or commit them.

Variable	Description
`DATABASE_URL`	Postgres connection string (Neon)
`BETTER_AUTH_SECRET`	Random secret, e.g. generated with `openssl rand -base64 32`
`BETTER_AUTH_URL`	Public URL of the site
`GOOGLE_CLIENT_ID`, `GOOGLE_CLIENT_SECRET`	Google OAuth client credentials

Example: Robinhood Chain Mainnet

See Robinhood Chain Mainnet for prerequisites and the checklist.

NEXT_PUBLIC_NETWORK=robinhood-mainnet
NEXT_PUBLIC_CHAIN_ID=4663
NEXT_PUBLIC_RPC_URL=https://rpc.mainnet.chain.robinhood.com
NEXT_PUBLIC_REOWN_PROJECT_ID=your_reown_project_id
NEXT_PUBLIC_payment token_ADDRESS=0x...   # real payment token, supplied by the operator
NEXT_PUBLIC_CARBON_CREDIT_NFT=0x...
NEXT_PUBLIC_CARBON_CREDIT_TOKEN=0x...
NEXT_PUBLIC_CARBON_MARKETPLACE=0x...
NEXT_PUBLIC_CARBON_PRICE_ORACLE=0x...
NEXT_PUBLIC_EMISSION_VERIFIER=0x...
NEXT_PUBLIC_CARBON_REGISTRY=0x...
NEXT_PUBLIC_DEPLOY_BLOCK=your_deploy_block

Example: Robinhood Chain Testnet

NEXT_PUBLIC_NETWORK=robinhood
NEXT_PUBLIC_CHAIN_ID=46630
NEXT_PUBLIC_RPC_URL=https://rpc.testnet.chain.robinhood.com/rpc
NEXT_PUBLIC_REOWN_PROJECT_ID=your_reown_project_id
NEXT_PUBLIC_CARBON_CREDIT_NFT=0x...
NEXT_PUBLIC_CARBON_CREDIT_TOKEN=0x...
NEXT_PUBLIC_CARBON_MARKETPLACE=0x...
NEXT_PUBLIC_CARBON_PRICE_ORACLE=0x...
NEXT_PUBLIC_EMISSION_VERIFIER=0x...
NEXT_PUBLIC_payment token_ADDRESS=0x...
NEXT_PUBLIC_CARBON_REGISTRY=0x...
NEXT_PUBLIC_DEPLOY_BLOCK=your_deploy_block

Deploying the contracts

Deployer keys, RPC overrides and explorer API keys are used only by your Hardhat setup, from a git-ignored .env. They are never read by the web app and must never be committed or placed in NEXT_PUBLIC_* variables. See Robinhood Chain Mainnet and Robinhood Chain Testnet.