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hyo.dev

Independent software studio · Seoul

Open code.Real impact

We build open source, developer tools, apps, and games. We share our code and what we learn with the community.

Meet the studio
Projects from the studio
Open sourceOpenIAPDeveloper toolsIAPKitGameSecondRoundAppBooKoohyo.dev

01Open source

Many platforms. One shared language.

Store differences should not define your architecture. We build the open standard that connects them.

OpenIAP

One API for every store

OpenIAP gives in-app purchases a consistent contract. Native modules handle each store; framework SDKs bring the same API to the stack you already use.

Explore the standardGitHub

Stores covered

Who's next?Your platform could be here — let's talk.

Framework SDKs

06

Native core

openiap-appleStoreKit 2openiap-googlePlay Billing
See a shared API example
store.ts
One shared APITypeScript
import {
  initConnection, fetchProducts,
} from 'expo-iap';

await initConnection();
await fetchProducts({
  skus: ['studio.pro'],
  type: 'in-app',
});
Start herenpx expo install expo-iap
API excerpt. Full setup in the guide.Setup guide

02What we ship

From open standards to shipped products.

The same foundation, put to work. IAPKit brings the purchase backend into one place.

The OpenIAP purchase backend

IAPKit

Purchase validation and entitlement infrastructure for the OpenIAP ecosystem — open source, with a hosted dashboard.

  • Open source
  • Hosted service
  • Free for developers
Explore IAPKitGitHub

Where it sits

Your app
IAPKitVerify · Entitle · Notify
Store ecosystems

App Store · Google Play · Amazon Appstore · Meta Horizon · Vega OS

  1. 01

    Purchase verification

    Server-side receipt validation for every store.

  2. 02

    Entitlements

    Subscription state tracked from store lifecycle events.

  3. 03

    MCP operations

    Your coding agent creates and syncs store products.

  4. 04

    Revenue visibility

    MRR, churn, and refunds from connected notifications.

03Open-source support

Kept open. Together.

Meta and Amazon Developer sponsor OpenIAP — funding the maintenance, testing, and shared infrastructure behind one purchase contract for every store.

MetaAngel sponsorAmazon DeveloperAngel sponsor

Where the support goes

View sponsorship options
  • Real-device testing
  • Shared IAPKit capacity
  • Store change response
  • SDK parity

04Track record

Code is only half the story.

We maintain software, share what we learn, and help developer communities grow. As a Linux Foundation Speaker, we work alongside developers across the world. OpenIAP is sustained by official sponsorship from Meta and Amazon.

References

Open Source Contributions

Managing open source projects whenever possible, sharing knowledge and expertise with the community.

GitHub

Community Leadership

Running a developer community, focusing on sharing technology, and working to build developer relations.

Community

05Selective engagements

Expertise for what’s next.

While not our main focus, we provide consulting services to select partners.

Hyo Dev provides expertise in the following areas:

  • 01

    Mobile & Web Development

  • 02

    Technology Strategy Planning

  • 03

    Team Mentoring

06Get in touch

Let’s build something worthwhile.

A platform to support, a project to move forward, or a good idea to share. We’d love to hear it.

Reach Out
hyo@hyo.dev