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How to Stream Solana Slots
How to Stream Solana Slots in Real Time With gRPC (+ Free Repo)
Clone the free repo solana-grpc-subscribe-slots, install dependencies, point the endpoint to https://grpc.gsnode.io, and you’ll have every new Solana slot hitting your terminal in < 50 ms.
A slot is the heartbeat of Solana. Every 400 ms (≈ 2,500 slots/hour) a validator may produce a block. If you can see the next slot before everybody else, you can:
- Front-run MEV bots (or build your own).
- Fire sniping transactions one slot earlier.
- Benchmark validator lag and RPC latency for your infra dashboard.
Who benefits?
| Use case | How slot streaming helps |
|---|---|
| DEX bots & MEV searchers | Predict when swaps will settle and time tip accounts. |
| Sniper tools | Know the precise slot where liquidity will appear. |
| Validator dashboards | Monitor slot skew and fork events in real time. |
Requirements & Quick Setup
Before start, you need the next requirements:
| Stack | Min version |
|---|---|
| Node.js | 18.x |
| TypeScript | 5.x |
| @grpc/grpc-js | 1.8.x |
| protobufjs | 7.x |
How to suscribe Solana Slots step by step
1. Clone (or copy) the repo
git clone https://github.com/gsnode/solana-grpc-subscribe-slots.git
cd solana-grpc-subscribe-slots
npm i
No Git? Copy index.ts into your own project and install the same dependencies.
2. Point to GS Node
Create a .env file:
GRPC_ENDPOINT=https://grpc.gsnode.io
3. Run it
ts-node index.ts
You should see a stream like:
slot: 249068235
slot: 249068236
slot: 249068237
…
Under the Hood: The 15-Line gRPC Call
import { SubscribeRequest, CommitmentLevel } from "./types";
const req: SubscribeRequest = {
accounts: {},
slots: { incoming_slots: {} },
transactions: {},
transactionsStatus: {},
entry: {},
blocks: {},
blocksMeta: {},
accountsDataSlice: [],
commitment: CommitmentLevel.PROCESSED // switch to CONFIRMED if you need more certainty
};
console.log("Streaming Solana slots…");
CommitmentLevel.PROCESSED means you get the event as soon as a validator votes, not when it’s finalized, exactly what bots need.
Pro Tips From Infra Engineers
- Parallel streams > single streamSpin up 3–5 workers, round-robin endpoints, and merge events. No single connection bottleneck.
- Back-pressure with queuesPipe slots into BullMQ (or Redis streams). Avoid dropping events during GC pauses.
- Track “slot lag”(network_latest – local_latest) > 100? Your VPS is falling behind—time to relocate or upgrade NIC.
- Store minimal dataA slot, timestamp, and maybe leaderPubkey is enough. Save disk; replay later via blocks if needed.
Common Pitfalls
- Mixing REST & gRPC leads to unpredictable latencies. Stick to one transport for mission-critical flows.
- Neglecting commitment levels: FINALIZED adds up to ~3 s delay—great for analytics, awful for MEV.
- Assuming slots == blocks: not every slot becomes a block; handle skipped slots in your logic.
Next Tutorials (Clone-and-Go)
| What you’ll learn | Repo |
|---|---|
| Account balance updates (USDC) | solana-grpc-subscribe-account |
| Token balance with data slice | …-account-slice |
| Filtered transactions (Serum only) | …-transaction-filtered |
| Block metadata stream | …-blocks-meta |
(Full index in the GS Node README)
Final CTA
- Star the repo if it saved you time.
- Fork & adapt the code; add metrics, queues, Redis—whatever your stack needs.
- Join us on Discord for latency tips, bot best-practices, and RPC status alerts → https://discord.gg/M8778yHKcV
