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Introducing the xCall Public Incentivized Testnet Program

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July 5, 2023



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Challenges for the xCall Public Incentivized Testnet Program are now live!

We are excited to announce the upcoming launch of the xCall Incentivized Testnet Program starting July 31, 2023. As we get closer to launching xCall on mainnet, we hope that many developers will use this opportunity to get familiar with xCall and find interesting applications of our cross-chain technology, in addition to helping us improve the product further.

Our ultimate goal is to make xCall the easiest tool that developers can use to add an interoperability feature to their products. To make this happen, we need your support!

We have 845,000 ICX (~200 K USD) in prizes committed to this program for quality submissions, so we look forward to your participation.

A Glimpse into the Testnet Program

The Incentivized xCall Testnet Program is intended to bootstrap the xCall cross-chain ecosystem through robust testing and product onboarding. In this initial phase, we will be testing:

  1. xCall integration with the Blockchain Transmission Protocol (BTP) (ICON’s interoperability protocol) cross-chain message transfer layer

  2. products and services between ICON Berlin, Ethereum Sepolia, BSC Testnet and the HAVAH Testnet.

Get your ideas ready for mainnet and try to break our system!

The program will focus on various themes:

  • Feature Testing — Perform targeted testing of xCall’s unique new features. How DevSec can you get? Let’s see if we can break the interoperability layers (unconfirmed transactions, desynchronized data, unverified messages, etc)

  • dApps & Templates — Develop alpha-level products and reusable technology components for projects that utilize xCall. Think token swaps, governance, NFT referencing, decentralized identity, etc.

  • Tooling — Simplify the overall development workflow Contributor Content — Publish creative content that raises awareness and educates the community on xCall’s value and benefits.

  • Wildcard — Be creative, do whatever you want!

Why You Should Participate

You’re early! This means that in addition to direct rewards for quality contributions to the program, another great draw to this program is that it is an invaluable opportunity to build meaningful connections with ICON’s core developer team and ICON developer community.

Because our goal is to build a lush product ecosystem for interoperable dApps using xCall technology, we are currently actively in search of development teams to build demonstrations and plan specific roadmaps for xCall-integrated products.

So we invite developers of all ecosystems to come take a look at the xCall product and take this opportunity to build.

After the incentivized testnet program closes, there will be many follow up resources and funding opportunities available to development teams for their products that use xCall, so now is the time to get involved!

Use this link to join a growing community of xCall developers on the ICON Discord.

How to Join

Once the program launches on the 31st of July, a ‘Challenges’ page will become available through the xCall Homepage where participants can submit a form after completing each challenge. Participants can submit entries for multiple challenges, but can only submit one entry per challenge.

Everyone in the community is welcome to participate, but the judges from the ICON Foundation will not be eligible to receive rewards. Everyone is required to abide by the Rules of Engagement or Code of Conduct. Violations, including exploiting software vulnerabilities or using malware to attack other participants, may result in disqualification. Identity checks are required for claiming rewards.

You can learn more about xCall and ICON through our xCall Docs. If you run into any issues while exploring xCall, join the ICON Discord to get support from our developer community!


This program is designed to evaluate the resilience and effectiveness of the xCall interoperability service and the associated BTP. Any judge involved in a challenge is ineligible for rewards. This includes members of the ICON Foundation: Eric Solomon, Cyrus Vorwald, and Min Kim. We reserve the right to modify, end, or extend the program at our discretion, in line with the program’s goals.

We look forward to your participation in the xCall Incentivized Testnet Program, a new chapter in ICON’s journey in blockchain development and innovation. Don’t miss this opportunity to become an early contributor in shaping the future of interoperability protocols!