The messaging protocol XMTP tweeted that it has launched a testnet with support from Coinbase Wallet, Circle, ENS, Alchemy, a16z crypto, Mask Network, and Faction. The official said that the micro-fee paid by the testnet application in USDC will be automatically allocated to the node operator; messages will be delivered in milliseconds through the off-chain broadcast network; and consensus on critical states will be maintained using Arbitrum Orbit on Base.