JSON-RPC connection guide

Subglow's JSON-RPC endpoint is a drop-in replacement for any standard Solana mainnet-beta RPC URL. Your existing client code works unchanged — only the URL moves.

Your quotas

Every paid plan bundles JSON-RPC on the same API key as gRPC. sendTransaction has its own bucket.

TypeScript / @solana/web3.js

import { Connection, PublicKey } from "@solana/web3.js";

const conn = new Connection(
  `https://rpc.subglow.io/${process.env.SUBGLOW_API_KEY}`,
  "confirmed",
);

// Reads
const slot = await conn.getSlot();
const { blockhash } = await conn.getLatestBlockhash();
const account = await conn.getAccountInfo(
  new PublicKey("So11111111111111111111111111111111111111112"),
);

// Writes — sendTransaction lives in a dedicated daily bucket
const sig = await conn.sendRawTransaction(signedTx.serialize(), {
  skipPreflight: false,
  maxRetries: 3,
});

Python / solders

import os, httpx
from solders.rpc.requests import GetSlot, GetLatestBlockhash, GetAccountInfo
from solders.pubkey import Pubkey

URL = f"https://rpc.subglow.io/{os.environ['SUBGLOW_API_KEY']}"

with httpx.Client(base_url=URL, timeout=10.0) as c:
    slot = c.post("/", content=GetSlot().to_json()).json()["result"]
    blockhash = c.post("/", content=GetLatestBlockhash().to_json()).json()["result"]
    info = c.post(
        "/",
        content=GetAccountInfo(
            Pubkey.from_string("So11111111111111111111111111111111111111112")
        ).to_json(),
    ).json()["result"]

Rust / solana-client

use solana_client::nonblocking::rpc_client::RpcClient;
use solana_sdk::{commitment_config::CommitmentConfig, pubkey::Pubkey};
use std::env;

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let url = format!(
        "https://rpc.subglow.io/{}",
        env::var("SUBGLOW_API_KEY")?,
    );
    let client = RpcClient::new_with_commitment(url, CommitmentConfig::confirmed());

    let slot = client.get_slot().await?;
    let hash = client.get_latest_blockhash().await?;
    let wsol: Pubkey = "So11111111111111111111111111111111111111112".parse()?;
    let info = client.get_account(&wsol).await?;

    println!("slot = {slot}, blockhash = {hash}, lamports = {}", info.lamports);
    Ok(())
}

Go / solana-go

package main

import (
    "context"
    "fmt"
    "os"

    "github.com/gagliardetto/solana-go"
    "github.com/gagliardetto/solana-go/rpc"
)

func main() {
    url := fmt.Sprintf("https://rpc.subglow.io/%s", os.Getenv("SUBGLOW_API_KEY"))
    client := rpc.New(url)

    slot, _ := client.GetSlot(context.Background(), rpc.CommitmentConfirmed)
    bh, _ := client.GetLatestBlockhash(context.Background(), rpc.CommitmentConfirmed)
    wsol := solana.MustPublicKeyFromBase58("So11111111111111111111111111111111111111112")
    info, _ := client.GetAccountInfo(context.Background(), wsol)

    fmt.Println(slot, bh.Value.Blockhash, info.Value.Lamports)
}

Method policy

Error codes you should handle

• -32001 archival-disabled — archival method attempted on a shared tier. Upgrade to Dedicated or refactor your query.
• 429 rate_limited — your daily RPC or sendTransaction bucket is exhausted. Counters reset at midnight UTC.
• 401 invalid_api_key — key missing, banned, or plan expired. Check your dashboard at /dashboard/usage.
• 5xx upstream_error — rare; retry with jittered backoff. We surface upstream Helius errors verbatim.