Solana clusters and RPC endpoints
Every sithbit command that touches the chain talks to a cluster — one of
Solana’s independent networks, each with its own validators, ledger, and
state — through an RPC endpoint URL. This page explains what the public
clusters are, which one SithBit runs on today, and what the URL you configure
actually points at.
The three public clusters
| Cluster | Public RPC endpoint | What it’s for |
|---|---|---|
| devnet | https://api.devnet.solana.com | The developer playground. State can be reset, and SOL is free via faucet airdrops — nothing on devnet has real value. |
| testnet | https://api.testnet.solana.com | Where Solana’s core contributors stress-test new validator releases. Also has a faucet, but it exists for network testing, not applications — rarely relevant to app users. |
| mainnet-beta | https://api.mainnet-beta.solana.com | The production network. SOL here is real money; there is no faucet. |
The clusters are completely separate: an account, program, or balance on one
does not exist on the others. Configuring an endpoint (sithbit config set --url <cluster>, or the JSON_RPC_URL environment variable — see
CLI Quickstart)
is what selects which network you’re talking to.
Which clusters SithBit uses
- Devnet hosts SithBit’s live test deployment: all three programs are deployed there under the devnet-only vanity IDs. Because devnet SOL is a free airdrop away, this is where the setup wizard can fund a fresh wallet automatically and let you claim a mailbox and send mail at zero cost.
- Local development doesn’t use a public cluster at all: the CLI
integration suite and day-to-day program work run against a
surfpool test validator on
127.0.0.1:8899— a private, disposable cluster of one. The development and pilot servers page covers the matching memory-backed mail binaries. - Mainnet-beta is where the production launch will live. The programs are not yet deployed there — the mainnet-track identities exist (see Program & PDA reference), but until launch, pointing the CLI at mainnet-beta finds no SithBit programs.
- Testnet is not used by SithBit.
Validators vs. RPC servers
The URL you configure is an RPC endpoint, not necessarily a validator.
A validator participates in consensus: it holds stake, votes on blocks, and
takes turns producing them. An RPC server runs the same node software
configured without voting — it replays the ledger to stay current, answers
JSON-RPC reads (balances, account data, transaction history), and forwards
the transactions you submit to the current block producers. Every cluster is
served by both kinds of node, and the public api.*.solana.com endpoints
above are RPC fleets, not voting validators.
The public endpoints are shared and rate-limited. That’s fine for CLI use and light development, but anything heavier — an MX server checking postage on every inbound message, or a production deployment — warrants a dedicated endpoint: either a commercial RPC provider or a self-run RPC node.
Further reading
- Solana’s clusters reference — the official page for the three public clusters and their endpoints.
- Solana JSON-RPC API — the full set of methods an RPC endpoint serves.
- Setting up an RPC node — Anza’s operations guide to running your own non-voting node.
See also
- Devnet-only vanity program IDs — why SithBit’s devnet deployment lives under a second program identity.
- Deploying to devnet/mainnet-beta: the modexp-free build — the build-flag mechanics of targeting a real cluster.
- Development and pilot servers — the local, memory-backed mail binaries that pair with a local validator.