dYdX vs Solana JSON RPC

dYdX is a decentralized perpetuals exchange that migrated from its StarkEx-based v3 to a Cosmos-chain v4 architecture, replacing the old exchange API with an open-source Indexer exposing markets, orderbooks, trades, and candles over REST and WebSocket. Anyone can run their own Indexer instance, but the public one at indexer.dydx.trade needs no signup for market-data reads — it's rate-limited rather than API-key gated.

Solana's public JSON-RPC clusters expose the full read/write RPC surface — accounts, transactions, blocks, and WebSocket subscriptions — with no signup or API key required. They're free to call, but Solana's own docs are explicit that the shared public endpoints are rate-limited to roughly 100 requests per 10 seconds per IP and are not intended for production traffic, pointing serious usage toward a dedicated third-party RPC provider instead.