RPC & Subscriptions

Typed HTTP JSON-RPC and WebSocket subscriptions with @solana/kit 7.0.0.

Recipe

Quick-reference recipe card - copy-paste ready.

import { createSolanaRpc, createSolanaRpcSubscriptions, address } from "@solana/kit";
 
const rpc = createSolanaRpc(process.env.RPC_URL!);
const balance = await rpc.getBalance(address("PUBKEY")).send();
 
const ws = createSolanaRpcSubscriptions(process.env.RPC_WSS_URL!);

When to reach for this:

• Any on-chain read from TypeScript (balances, accounts, blocks).
• Live UI updates via account or signature subscriptions.
• Server-side reads in Next.js route handlers.
• Replacing untyped fetch calls to JSON-RPC.

Working Example

import { createSolanaRpc, createSolanaRpcSubscriptions, address } from "@solana/kit";
 
const rpc = createSolanaRpc("https://api.devnet.solana.com");
const rpcSubscriptions = createSolanaRpcSubscriptions("wss://api.devnet.solana.com");
 
async function watchBalance(owner: string) {
  const acct = address(owner);
  const { value } = await rpc.getBalance(acct).send();
  console.log("initial", value);
 
  const abort = new AbortController();
  const stream = await rpcSubscriptions
    .accountNotifications(acct, { commitment: "confirmed" })
    .subscribe({ abortSignal: abort.signal });
 
  for await (const n of stream) {
    console.log("update", n.value.lamports);
  }
}

What this demonstrates:

• HTTP RPC for point-in-time reads with .send().
• Matching WSS URL for push notifications.
• AbortController for cleanup.

Deep Dive

How It Works

• createSolanaRpc wraps JSON-RPC 2.0 with typed methods and responses.
• createSolanaRpcSubscriptions opens a WebSocket and exposes async iterable notifications.
• Commitment on calls controls staleness vs finality.
• Provider URLs often embed API keys as query params.

Common RPC Methods

TypeScript Notes

// Pass commitment on reads that power treasury UI
await rpc.getBalance(owner, { commitment: "finalized" }).send();

Gotchas

• HTTP URL on WebSocket client - connection fails silently or throws. Fix: use wss:// from provider docs.
• Public RPC rate limits - 429s under load. Fix: dedicated devnet/mainnet endpoint.
• Subscription leaks - tabs left open exhaust provider caps. Fix: abort on unmount.
• Assuming DAS on every RPC - getAsset needs DAS-enabled hosts. Fix: capability matrix per vendor.
• Skipping .send() - RPC builders are lazy until sent. Fix: always chain .send().

Alternatives

FAQs

Related

• RPC Basics - commitment and clusters
• @solana/kit Basics - kit primer
• Signing & Sending - submit path

Stack versions: This page was written for Agave 4.1.1, Solana CLI 3.0.10, Anchor 0.32.1, anchor-lang 0.32.1, Rust 1.91.1, @solana/kit 7.0.0, Surfpool 0.12.0, and LiteSVM 0.6.x.