Starkzap Brings Crypto Powers to Any App

In 2025, I played through Season 1 of Realms: Eternum on Starknet. It was a blast, largely because it just felt like playing a solid mainstream strategy game. The onchain elements were abstracted away.

You could sign into the game with a social login like Discord, avoid transaction deluges via session keys, and make trades for free through a paymaster. Not bad! Really good, in fact. This UX flow was an obvious blueprint for other consumer apps to make their way onto crypto rails.

So, what if you packaged the pillars that made Eternum S1 so slick with even more utility, and put it all into a single developer kit so that any app could use it for streamlined, plug-and-go crypto powers?

Well, you'd get Starkzap, which is fortunately now open for anyone to use.

What is Starkzap?

Starkzap is an open-source TypeScript SDK that StarkWare launched this week so developers can easily embed onchain capabilities into their apps.

One command is all it takes to dive in: npm install starkzap. From there, all of the architecture is modular, so builders can opt for whatever configurations they need.

On the wallet side, Starkzap supports three authentication backends:

• Privy, which handles social and email login with server-side key management so users never touch a seed phrase.
• Cartridge Controller, which is tuned for gaming and lets users sign in with Google, Twitter, or biometrics.
• Plus, Ready and Braavos account templates, which are good for teams that want more traditional wallet setups.

As for transactions, Starkzap supports both AVNU and Cartridge paymaster tech for sponsored gas. This way, apps can offer fee-less experiences without having to build any payments plumbing themselves.

On the DeFi side of things, the SDK also ships with modules for ERC-20 operations (transfers, balance checks, approvals), staking across STRK, BTC, and USDC, and a transaction builder for handling batching and fee estimations.

And this is all just Starkzap as it stands out of the gate. In the future, look for more modules and integrations to arrive, like support for bridging via Near Intents or lending via Vesu.

Build, Brother

Right now, if an app wanted to deploy even a basic crypto feature, it'd entail manually wiring up wallet management, fee logic, DeFi protocols, etc.

That whole process could take many weeks.

In contrast, Starkzap flattens that work into a single SDK, so that wiring process only has to take days, hours, or minutes.

This resource can be huge for human builders who want to expand their consumer apps into the onchain frontier. But also note in the context of vibe coding or autonomous onchain agents how Starkzap can serve as an execution layer so AI can bypass infra building.

Ultimately, Starkzap is a bet that eliminating developer friction as a bottleneck will lead to a bloom of onchain consumer apps.

Starknet is already home to rising hits like Loot Survivor 2 and Focus Tree. What happens when there are dozens of apps like these on the L2? We'll have to wait and see, but this is the future that Starkzap is pointing to.

What made Eternum S1 feel like a real game was good infra that was thoughtfully composed – Starkzap takes the same legos, adds more goodies, and pre-packages it all for anyone to deploy.

This has the potential to become a considerable catalyst in the Starknet ecosystem going forward, so keep it on your radar.