blockSubscribe

blockSubscribe opens a Solana PubSub subscription that pushes a full block object — its transactions, rewards paid in SOL (lamports), and metadata — each time a new block is produced. Solana confirms a block roughly every 400ms at very high throughput, so this is a firehose of the freshest on-chain state. You can take every block with the "all" filter or narrow to blocks that touch a given account or program. The matching JSON-RPC endpoint is https://solana.therpc.io/YOUR_API_KEY, and you stop the stream by passing the returned subscription id to blockUnsubscribe.

Use cases

• Feed a live indexer block by block as Solana produces them at its ~400ms cadence, instead of catching up with repeated getBlock calls.
• React only to blocks that mention a specific program or account by passing { mentionsAccountOrProgram: pubkey } — for example a Jupiter or Raydium program id.
• Trim the payload with transactionDetails ("signatures" or "none") and showRewards: false for a lighter, lower-bandwidth feed.

Parameters

Response

Example request

1# Open a WebSocket connection (e.g. with wscat) and send the subscribe request:
2wscat -c wss://solana.therpc.io/YOUR_API_KEY
3# then send:
4> {"jsonrpc":"2.0","id":1,"method":"blockSubscribe","params":[{},{}]}

Errors & troubleshooting

Common pitfalls

• This is one of the heaviest Solana subscriptions, so many validators leave it off — it requires the --rpc-pubsub-enable-block-subscription flag and providers often gate it. Check availability before you build on it.
• Set maxSupportedTransactionVersion: 0 in the config, or versioned (v0) transactions in a block will cause the notification to error out.
• This is a WebSocket-only method — it streams over a wss PubSub connection, and you stop it by passing the subscription id to blockUnsubscribe.

Supported networks

• Mainnet
• Devnet

See also

• getBlock
• slotSubscribe