Watching a Solana wallet without running your own RPC node

Watching a Solana wallet without running your own RPC node

If you want to know the moment a specific Solana wallet's balance moves — a treasury, a whale you're tracking, your own hot wallet for a security check — the "proper" way people reach for is running a dedicated indexer or paying for a webhook service like Helius. For a single wallet with modest polling needs, that's overkill.

Solana's public RPC (api.mainnet-beta.solana.com) is rate-limited but free, and it's enough to poll a wallet's SOL and SPL token balances on a schedule without an API key at all. Here's the pattern I used, in case you're about to build a similar watcher and don't want to pay for infra you don't need yet.

The loop

1. Poll every 5 minutes — getBalance for SOL, getTokenAccountsByOwner for SPL tokens, against the public RPC endpoint. No auth, no key.
2. Diff against last known balance — stored between runs (a simple key-value store is enough; I used n8n's built-in static data, but a Sheet or a Redis key works the same).
3. Threshold check — only fire an alert if the change exceeds a threshold you set. Without this, you get pinged on every dust transaction and start ignoring the channel within a day — the threshold is what makes the alert actually useful instead of noise.
4. Alert with context — a Telegram message with the delta and a link straight to the transaction on Solscan, so you don't have to go look it up.

Where the public RPC runs out

At low polling frequency (minutes, not seconds) and a handful of wallets, the public endpoint holds up fine. If you're watching dozens of wallets or need sub-minute latency, you'll hit rate limits and want to swap in a dedicated RPC (Helius, QuickNode, Triton) — the workflow is built so that's a one-field change, not a rewrite, since the RPC URL is a single credential.

If you want the built version

Packaged as an n8n workflow — polling, diffing, thresholding, and the Telegram alert with the Solscan link already wired up:

👉 https://shop.lumnika.com/solana-wallet-watcher.html?utm_source=devto&utm_medium=article&utm_campaign=solana-wallet-watcher

$14.99, one-time, no API key required to get started since it uses the public RPC by default.

Anyone else tracking wallets for security/ops reasons rather than trading? Curious what thresholds people settled on before the alerts stopped being noise.