Stream scheduled Solana transactions
Preconfirmations stream transactions the instant a validator's scheduler commits to executing them — earlier than shred delivery and confirmed-commitment streams.
Available on Professional plans and higher
A filtered firehose, built for the fast path
Open a single preconfSubscribe WebSocket and stream scheduled transactions as compact binary frames, a fixed 18-byte header your decoder reads in nanoseconds.
- Lifecycle stage
- Scheduled txn
- Transport
- WebSocket
- Price per message
- 10 credits
Preconfs are an early signal, not a guarantee
A preconfirmation means a validator's scheduler has committed to executing the transaction, but it has not yet landed onchain and could still fail or drop. Coverage scales with participating validator stake, so expect and account for gaps.
The earliest point in the transaction lifecycle
Latency increases from left to right. Preconfirmations tap the scheduled-transaction stage before shreds exist.
Subscribe once, react first
Open a subscription
Connect to the Helius Gatekeeper endpoint and send a single `preconfSubscribe` request. Filter by account, region, or status. Only stream what you care about.
Get the earliest signal
Notifications arrive as compact binary frames with the slot, transaction index, status, and full transaction as soon as the scheduler commits to executing them.
Pay per message
10 credits per streamed transaction, billed from your plan like any Helius WebSocket subscription. Preconfirmations is a new product and pricing is subject to change.
{
"jsonrpc": "2.0",
"id": 1,
"method": "preconfSubscribe",
"params": [
{
"failed": false,
"regionInclude": ["ewr", "fra"],
"accountInclude": ["TARGET_WALLET_ADDRESS"],
"accountExclude": ["TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA"],
"accountRequired": ["11111111111111111111111111111111"]
}
]
}Open a subscription
Connect to the Helius Gatekeeper endpoint and send a single `preconfSubscribe` request. Filter by account, region, or status. Only stream what you care about.
Get the earliest signal
Notifications arrive as compact binary frames with the slot, transaction index, status, and full transaction as soon as the scheduler commits to executing them.
Pay per message
10 credits per streamed transaction, billed from your plan like any Helius WebSocket subscription. Preconfirmations is a new product and pricing is subject to change.
{
"jsonrpc": "2.0",
"id": 1,
"method": "preconfSubscribe",
"params": [
{
"failed": false,
"regionInclude": ["ewr", "fra"],
"accountInclude": ["TARGET_WALLET_ADDRESS"],
"accountExclude": ["TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA"],
"accountRequired": ["11111111111111111111111111111111"]
}
]
}Who are preconfs for?
Prop AMMs & HFTs
React to onchain activity at the earliest possible moment to stay ahead of the book
Snipers
See new launches the instant they're scheduled, not after they're confirmed
Copy traders
Mirror a target wallet's trades the moment their transaction is scheduled
Liquidation bots
Detect liquidation opportunities faster than your competitors
Arbitrageurs
Catch cross-DEX price divergences before competitors close the gaps
Searchers
Use preconfs to act on order flow your competitors can't see
Earn revenue by sending preconfirmations
Any validator can join and earn revenue by sending preconfirmations to Helius. The more participating stake, the broader the coverage is for everyone.
Preconfirmations (Preconfs) stream transactions at the earliest point they can be observed: the moment a validator schedules them, before they are collected into entries and converted into shreds. This is the lowest-latency transaction signal Helius offers.
Yes, there are gaps in coverage. Preconfirmations are only available for transactions scheduled by validators that forward their stream to Helius. Coverage scales with the share of network stake currently sending to Helius, so the stream is not continuous. Your trading system should account for gaps in coverage.
Helius Preconfirmations require a Professional plan or higher and cost 10 credits per message. Each streamed transaction equals one message. Preconfirmations are billed from your plan. See Credits for details.
Get the earliest signal on Solana
Subscribe to preconfs and react the moment txs are scheduled. Available on Pro plans only.