# Achieving Zero-Slot Execution with Sender and LaserStream 0xIchigo **Developer Experience Engineer** 13 min read Sep 11, 2025 ## [Introduction](/content/blog/zero-slot#introduction/index.html) Everyone wants their transactions to land as fast as possible. However, as Solana trading infrastructure becomes more sophisticated and on-chain markets mature, simply sending a transaction and hoping for the best doesn’t cut it anymore—congestion, competition, and network quirks turn “fast” into “frustratingly unreliable.” The goal is straightforward: when a signal hits—a price crosses a certain threshold, an account updates, a program is invoked—a transaction reacting to that signal should land in the same slot. That’s the essence of **zero-slot execution**, where detection and submission happen so seamlessly that opportunities are captured before they vanish in milliseconds. In practice, this is increasingly difficult to achieve, requiring ultra-low-latency signal ingestion and reliable, deterministic delivery. Helius provides both. By combining [LaserStream](/content/laserstream/index.html) for lightning-fast event detection with [Sender](/content/sender/index.html) for optimized transaction submission, Helius delivers an end-to-end pipeline purpose-built for zero-slot execution. ## [LaserStream and Sender: A Unified Workflow](/content/blog/zero-slot#laserstream-and-sender-a-unified-workflow/index.html) Sender complements LaserStream to create a seamless, end-to-end pipeline for responsive trading workflows on Solana. In practice, 1. **Use LaserStream to Listen For Signals**: Shred-level ingestion and advanced filtering deliver real-time on-chain events faster than any other pipeline. 2. **Use Helius Sender to React to Signals**: Transactions are dispatched via SWQoS and Jito simultaneously, with global routing and validator-aware delivery to maximize inclusion and minimize latency. 3. **Profit**: Together, these services make securing profitable opportunities achievable in practice, not just theory. With Helius, developers get a vertically integrated stack purpose-built for speed and reliability: - No need to stitch together third-party RPCs, relays, or homegrown infrastructure. - Global routing, automatic retries, and validator-aware delivery are built in. ## [Finding the Right Signal](/content/blog/zero-slot#finding-the-right-signal/index.html) Arbitrages and liquidations can vanish in milliseconds on Solana. Detecting the right on-chain signal in a timely manner is of paramount importance. Here, a “signal” refers to any real-time event, such as a token transfer, account update, or program invocation, which presents a tradeable opportunity. Without ultra-low-latency ingestion, edges evaporate before they can be acted upon, making reliable, high-speed data streaming essential. [LaserStream](/content/docs/laserstream/index.html) is Helius’ next-generation Solana data streaming service, which combines the speed of [shred-level](/content/blog/solana-shreds#what-are-shreds/index.html) ingestion with the reliability and reach of a globally distributed service, without the cost or operational headaches of running multiple dedicated nodes. ## [Optimizing Transaction Sending Workflows](/content/blog/zero-slot#optimizing-transaction-sending-workflows/index.html) Transaction inclusion is a multi-variable optimization problem that requires a deep understanding of multiple areas of Solana’s architecture. Factors such as arrival time, simulation success, account lock conflicts, associated transaction fees, and priority all interplay to determine when a given transaction executes on-chain. To effectively land a transaction on Solana today, a developer needs to: ### [Use Staked Connections](/content/blog/zero-slot#use-staked-connections/index.html) Staked connections leverage Solana’s [Stake-Weighted Quality of Service (SWQoS)](/content/blog/stake-weighted-quality-of-service-everything-you-need-to-know/index.html), prioritizing traffic from staked validators and paired RPCs for better leader reachability and propagation speed. ### [Add Dynamic Priority Fees](/content/blog/zero-slot#add-dynamic-priority-fees/index.html) [Priority fees](/content/blog/priority-fees-understanding-solanas-transaction-fee-mechanics/index.html) help boost a transaction’s position in the leader’s scheduler in the Banking Stage. ### [Optimize CU Usage](/content/blog/zero-slot#optimize-cu-usage/index.html) Compute Units (CUs) quantify a transaction’s computational demand. Exceeding the requested budget triggers execution failures, while over-requesting inflates priority costs. ### [Use the Proper Commitment Level For Fetching Data](/content/blog/zero-slot#use-the-proper-commitment-level-for-fetching-data/index.html) [Commitment levels](/content/blog/solana-commitment-levels/index.html) determine the confirmation depth for fetched data like blockhashes. ### [Skip Preflight Checks](/content/blog/zero-slot#skip-preflight-checks/index.html) Preflight checks simulate a transaction on the RPC node prior to submission, verifying signatures, instructions, and execution to catch errors early. ### [Setting the maxRetries Parameter to Zero](/content/blog/zero-slot#setting-the-maxretries-parameter-to-zero/index.html) The **maxRetries** parameter in the **sendTransaction** method enables automatic resends on the RPC side in the event of failures. ### [Consider Using Jito](/content/blog/zero-slot#consider-using-jito/index.html) Jito tips enable off-chain bundles via MEV auctions, ensuring guaranteed transaction inclusion and ordering for partial blocks. ## [Sender](/content/blog/zero-slot#sender/index.html) [Sender](/content/docs/sending-transactions/sender/index.html) is Helius’s ultra-low-latency transaction sending service that leverages SWQoS and Jito’s off-chain auctions for MEV-optimized inclusion. ## [How Sender Works](/content/blog/zero-slot#how-sender-works/index.html) Sender processes transactions via a simple JSON-RPC POST request, where the transaction is serialized to base64 and submitted to one of its endpoints. ## [How to Get Started](/content/blog/zero-slot#how-to-get-started/index.html) ### [Working With LaserStream](/content/blog/zero-slot#working-with-laserstream/index.html) LaserStream offers the same developer experience as working with gRPC. Simply change the endpoint and API key to point to LaserStream. ### [Working With Sender](/content/blog/zero-slot#working-with-sender/index.html) Helius Sender is available to all users and doesn’t consume any additional credits—no paid plans or special access required. ### [Working With LaserStream and Sender](/content/blog/zero-slot#working-with-laserstream-and-sender/index.html) The real power of Helius comes from combining LaserStream and Sender into a single workflow. ## [Why Helius](/content/blog/zero-slot#why-helius/index.html) Helius stands out as the premier choice for optimizing transaction workflows on Solana, thanks to our position as [the network’s largest validator by stake](https://orb.helius.dev/stats?cluster=mainnet-beta). Staked bandwidth is therefore not an issue for us, effectively eliminating any bottlenecks or failure cases related to transaction deprioritization or packet drops during congestion. ## [Faster](/content/blog/zero-slot#faster/index.html) LaserStream reduces latency and uncertainty. The sooner a signal arrives, the more predictable the outcomes become. Combined with Sender, transactions sent in reaction to a signal enable greater operational confidence.