Preconfirmations: The Earliest Transaction Signal on Solana

Stream scheduled transactions the moment a validator commits to executing them — before they are shredded. The lowest-latency transaction signal Helius offers, delivered over a WebSocket subscription.

Use Sender Max (min tip: 0.001 SOL) to act on Preconfirmations. A preconfirmation only pays off if you land your transaction first — Sender Max is the fastest way to do that. Build on Sender Max from the start to get the full benefit of Preconfirmations.

Overview

Preconfirmations 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 — earlier than Shred Delivery and earlier than processed commitment streams.

You subscribe over a WebSocket with the preconfSubscribe method and receive each scheduled transaction as it happens.

Preconfirmations are served from the Helius Gatekeeper endpoint, wss://beta.helius-rpc.com. The beta hostname refers to the Gatekeeper rollout, not the maturity of Preconfirmations — it will become the standard endpoint as traffic migrates to Gatekeeper.

Lowest Latency

Transactions are delivered at the scheduled-transaction stage, ahead of shreds and processed commitment streams

WebSocket Streaming

Subscribe once with preconfSubscribe and receive a continuous stream of scheduled transactions

Credit-Based Pricing

Professional plan or higher; 10 credits per message (each streamed transaction)

Built for Traders

React to onchain activity before it lands, for propAMMs, snipers, copy traders, and liquidation bots

Where Preconfirmations sit in the pipeline

A transaction passes through several stages inside a validator before it lands onchain. Latency increases left to right — the further right you observe, the later you learn about the transaction.

Preconfirmations deliver scheduled transactions one stage before shreds.

Preconfirmations tap the scheduled-transaction stage — after the validator has scheduled the transaction, but before being collected into an entry and turned into shreds. That makes them strictly lower latency than shred-based delivery for the same transaction.

When to use Preconfirmations

Good fit

propAMMs, snipers, copy traders, and liquidation bots — any strategy that needs to react to a transaction as early as physically possible.

Consider alternatives

For full historical or confirmed data, use LaserStream or Enhanced WebSockets. For raw network data, see Shred Delivery.

A preconfirmation is an early signal, not a guarantee. A scheduled transaction has not yet landed onchain and could still fail or be dropped. Confirm landing through standard commitment checks before treating it as final.

Pricing

Preconfirmations require a Professional plan or higher and cost 10 credits per message — one message per streamed transaction — billed from your plan. See Credits for details.

Preconfirmations is a new product and pricing is subject to change.

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.

Expect gaps. During slots whose leader doesn’t forward to Helius, you’ll receive no preconfirmation messages for that slot. Design your integration to tolerate these gaps — don’t assume an unbroken stream, and fall back to other signals such as LaserStream or Shred Delivery when you need continuous coverage.

Coverage grows as more validators forward to Helius. If you operate a validator, you can help close these gaps and earn revenue.

For validators

Operate a validator? You can earn revenue by forwarding your preconfirmation stream to Helius — and improve coverage for everyone consuming Preconfirmations.

Validators: earn by sending Preconfirmations

Learn how to start forwarding preconfirmations and earn revenue.

Next steps

preconfSubscribe reference

Subscribe, message format, and a complete WebSocket example.

Helius Sender

Pair Preconfirmations with Sender to act on what you see with the fastest landing.