Web3 Builder Hub FAQ
What is a blockchain testnet?
A testnet is a separate blockchain network that mirrors mainnet functionality using tokens with no monetary value. Developers deploy and test smart contracts, simulate transactions, and debug applications on testnets before mainnet deployment. Ethereum uses Sepolia and Holesky. Solana uses Devnet. Base uses Base Sepolia. Most L2s run Sepolia-based testnets.
What is an RPC endpoint?
An RPC (Remote Procedure Call) endpoint is a URL that applications use to communicate with a blockchain node. Read requests return balances, transaction data, and contract state. Write requests submit transactions and deploy contracts. Public RPCs are free but rate-limited, typically 10-100 requests per second. Private providers (Alchemy, Infura, QuickNode) offer higher throughput, WebSocket support, and archive node access with SLA-backed uptime.
How do testnet faucets work?
Testnet faucets distribute free test tokens to developer wallets. Connect a wallet or paste an address, and the faucet sends test ETH, SOL, or the chain's native token. Most faucets enforce daily limits and cooldown periods. Some require a minimum mainnet balance or social account verification to prevent abuse.
Which wallet should I use for Web3 development?
MetaMask is the standard wallet for EVM chains (Ethereum, Arbitrum, Base, Polygon, Optimism). Phantom handles Solana. Keplr handles Cosmos SDK chains. For multi-chain development, Rabby supports most EVM networks. Choose based on the target chain and whether hardware wallet integration is required.
What chains does this hub cover?
51 blockchains including Ethereum, Solana, Arbitrum, Base, Polygon, Optimism, Avalanche, zkSync, Starknet, NEAR, Sui, Aptos, TON, Cardano, Polkadot, Cosmos Hub, Berachain, Monad, and others. Each chain has pages for testnets, RPC endpoints, faucets, and wallets.
What is the difference between a public and private RPC?
Public RPCs are free endpoints maintained by chain foundations or community operators. They have rate limits and no uptime guarantees. Private RPCs from providers like Alchemy, Infura, or QuickNode offer dedicated throughput, WebSocket connections, archive node access, and SLA-backed availability. Production applications typically require private RPCs.
How do I add a custom network to my wallet?
Open wallet settings, navigate to Networks, and add a new network. Required fields: RPC URL, chain ID, currency symbol, and block explorer URL. The RPC pages in this hub list these values for every supported chain.
How is this data maintained?
The DIA team curates all resources. RPC endpoints are verified for availability. Faucet links are tested. Wallet listings reflect current chain compatibility. Content is maintained in Notion and published through DIA's infrastructure. Updates happen on a rolling basis as chains launch new testnets or deprecate old ones.