What does blockSubscribe do?

Subscribes to new blocks and streams each full block — optionally filtered to blocks mentioning a given account or program — as it is confirmed or finalized.

How many credits does blockSubscribe cost?

blockSubscribe costs 1 credit(s) per call on Triport by default.

Is blockSubscribe available over WebSocket?

Yes, blockSubscribe supports WebSocket.

blockSubscribe

Last updated: June 20, 2026

blockSubscribe pushes entire blocks over the WebSocket as the cluster produces them, sparing you the poll-getBlocks-then-fetch-each-getBlock loop. Each blockNotification carries the slot and a block object in the same shape getBlock returns — blockhash, parent linkage, timestamp, rewards, and the transaction list at the detail level you configure.

The first parameter is a filter: the string "all" streams every block, while {"mentionsAccountOrProgram": "<pubkey>"} narrows the stream to blocks containing at least one transaction that references the given account or program — and in that case the notification's transaction list includes only the matching transactions, not the whole block's. The config object then controls payload weight: transactionDetails (full, accounts, signatures, or none), encoding (json, jsonParsed, base58, base64), showRewards, and maxSupportedTransactionVersion — set the latter to 0 or versioned transactions in the block will make decoding fail. commitment may be confirmed (default) or finalized; processed is not supported for block subscriptions.

Use it when you genuinely need block-granular data live: feeding a real-time indexer or analytics pipeline, computing per-block metrics (fees, compute units, transaction counts), or tailing all activity of one program with block-level ordering guarantees. If you only care about individual account changes or log lines, accountSubscribe/logsSubscribe are far lighter.

Caveats worth planning around. In stock Solana this method is marked unstable and only works on nodes started with the block-subscription flag enabled — Triport routes /ws/sol block subscriptions to capable nodes, but portability of your code to other RPC setups is not guaranteed. Full-detail notifications are large (hundreds of KB, easily multiple MB per block), so budget bandwidth and parsing time, and prefer transactionDetails: "signatures" or a mentions filter when you can. Skipped slots produce no notification. The stream is session-scoped: after a reconnect, resubscribe and backfill missed slots with getBlocks + getBlock. Stop with blockUnsubscribe.

Parameters

This method takes no parameters.

Returns

blockSubscribe return value
Field	Type
result	object

Examples

cURLTypeScriptPython

curl https://triport.io/sol \
  -X POST -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer <api-key>' \
  -d '{"id":1,"method":"blockSubscribe","params":[],"jsonrpc":"2.0"}'

const res = await fetch("https://triport.io/sol", {
  method: "POST",
  headers: { "Content-Type": "application/json", Authorization: "Bearer <api-key>" },
  body: JSON.stringify({
  "id": 1,
  "method": "blockSubscribe",
  "params": [],
  "jsonrpc": "2.0"
}),
});
const data = await res.json();

import requests
resp = requests.post(
    "https://triport.io/sol",
    headers={"Authorization": "Bearer <api-key>"},
    json={"id":1,"method":"blockSubscribe","params":[],"jsonrpc":"2.0"},
)
print(resp.json())

Usage

Transport: WebSocket.
Networks: mainnet, devnet, testnet.
Credit cost: 1 per call.

FAQ

What does blockSubscribe do?: Subscribes to new blocks and streams each full block — optionally filtered to blocks mentioning a given account or program — as it is confirmed or finalized.
How many credits does blockSubscribe cost?: blockSubscribe costs 1 credit(s) per call on Triport by default.
Is blockSubscribe available over WebSocket?: Yes, blockSubscribe supports WebSocket.