Gas Tank.

Origin

While dogfooding the Kraken Wallet app, I tried to send Wrapped BTC and couldn't. I had the asset, I had a destination, and the transaction failed. The reason — I didn't have enough ETH to cover the gas fee on a token I wasn't even sending — took me a while to untangle. If it confused me, it's confusing a lot of people. Gas Tank is my attempt to fix it.

The problem

Gas fees are paid in the native token of whatever network you're transacting on. Send USDC on Ethereum and you still need ETH in your wallet to cover the fee, even though you're not sending ETH. Want to send your entire ETH balance? You can't. You need to mentally reserve enough for gas, and gas costs fluctuate in real time so you don't know exactly how much to hold back.

For a non-crypto-native user, this creates a hidden calculation that nobody explains upfront. Your balance shows one number. The amount you can actually send is lower, by a margin that changes by the minute and varies across networks. Get it wrong and the transaction fails. Sometimes the fee is taken anyway. The user did everything right and the money didn't move.

The problem isn't the cost of gas. It's that gas turns every transaction into a mental arithmetic exercise at the exact moment the user is trying to do something else.

The reframe

Gas Tank separates gas from the transaction entirely. Rather than a reserve you mentally subtract from your balance every time you send, gas becomes a pre-funded system resource — a separate pot that covers network fees automatically across every transaction you make.

The shift is from "how much ETH do I need to hold back for gas on this network right now?" to "my Gas Tank is active. I have approximately 37 transactions remaining."

One mental model requires a calculation the user shouldn't have to make. The other requires none.

Three screens, one system

The wallet view

Gas Tank appears as a system resource within the wallet, visually distinct from your assets and placed above them. The placement is deliberate. Gas isn't something you hold, it's infrastructure that makes the wallet work. Treating it like an asset — listed alongside ETH and USDC — implies it's something you trade or manage like the rest of your portfolio. Separating it establishes the right mental model before the user ever tries to send anything. The status and approximate transaction count are visible at a glance. There's nothing to calculate before you act.

The Gas Tank dashboard

The dashboard expresses balance as both a dollar amount and an approximate transaction count, because dollar amounts alone don't tell you whether you have enough to transact. Showing "37 transactions remaining" makes the resource immediately legible without requiring the user to understand network fee mechanics. Usage stats for the last seven days — transactions made, total gas spent, average fee per transaction — give context without clutter. Per-network average costs sit below, for users who want to go deeper. The information hierarchy moves from what you need to know to what you might want to know.

Funding the tank

The funding screen surfaces estimated coverage in human terms before you commit: "approximately 38 swaps and sends, based on current network conditions." You're not adding ETH for gas on a specific network. You're buying transaction capacity that works across chains. An auto top-up rule — replenish when the balance drops below a set threshold — closes the loop on failed transactions before they can happen, removing the need to monitor gas balances manually.

Why it matters

Failed transactions are one of the most trust-eroding experiences in crypto. There's no clear error. No obvious fix. Just a transaction that didn't go through and a fee that was charged anyway. For a user trying to build a habit of using a self-custody wallet, that experience is often the last one.

Gas Tank doesn't make gas cheaper. It makes gas invisible at the moment it matters most and predictable at the moment you choose to think about it. The budget is always visible. The math is never yours to do.

What I'd want to test

This is a concept, not a shipped product. The reframe from gas-as-reserve to gas-as-system-resource is the core hypothesis, and it needs validation before it's a design recommendation.

The questions I'd want to answer: does the transaction count framing ("37 remaining") actually reduce pre-send anxiety compared to a dollar balance? Do users understand that the Gas Tank covers fees across chains, or do they assume it's network-specific? Does auto top-up reduce failed transactions in practice, or does it create anxiety about unexpected charges?

The right test would be a moderated usability session with non-crypto-native users, watching how they interpret the wallet view and the funding screen before making their first send. That's where the model either holds or breaks.

Personal concept project. Built in Figma Make, January 2026.