Is there a free Robinhood Chain RPC endpoint?
Yes, two. Robinhood runs a public endpoint at https://rpc.mainnet.chain.robinhood.com, and PublicNode offers a free keyless one at https://robinhood-rpc.publicnode.com with MEV protection. Several commercial providers also have free tiers.
Robinhood's own documentation describes the public endpoint as rate-limited and unsuitable for production. It is fine for a wallet, a script, or development.
PublicNode requires no API key and no signup, and advertises MEV protection — a feature several commercial providers charge for. QuickNode, GetBlock, dRPC and Validation Cloud all offer free tiers with higher limits in exchange for a key.
Two free production-adjacent endpoints is why plain RPC resale on this chain has almost no pricing power, and why RobinhoodRPC gives RPC away and charges for the data layer above it.