The Solana Foundation public RPC at https://api.mainnet-beta.solana.com is the free endpoint that ships in every Solana SDK quickstart. It's useful for what it is. It is not what you should ship apps on.
What it actually is
A small set of RPC nodes operated by the Solana Foundation as a courtesy for the developer ecosystem. Heavily rate-limited per IP. No SLA. No support. No DAS. No enhanced transactions. No webhooks. No anything beyond the bare RPC spec.
What it's good for
- Local development. First-time Solana setup, hello-world programs, hackathon kickoff.
- Scripts you run from your laptop. One-off airdrop verification, a manual transaction lookup.
- Validator quickstart. When you're learning, before you have an API key from anywhere.
What it's bad for
- Production dapps. The rate limits will hit your users and they'll see
429errors. The Solana Foundation explicitly asks production apps not to use it. - Anything reading historical data. Methods like
getSignaturesForAddresswith old offsets routinely fail or take minutes. - Anything subscribing to WebSockets. The public WebSocket endpoint is overloaded and drops connections.
The right migration path
Use the public RPC during local dev → ship to a free tier (Helius, Syndica, QuickNode) before mainnet → upgrade to paid when usage grows past the free quota. Never ship a production app pointed at api.mainnet-beta.solana.com.