Fast-tracking development of blockchain banking applications using Open Banking


El Salvador is the first country in the world to give Bitcoin the status of legal tender. This is a historic milestone and could prove the feasibility of widespread cryptocurrency adoption, but introduces a number of operational and regulatory implications.

Banco Hipotecario de El Salvador is a first-tier national bank with a commercial focus. When faced with the Bitcoin Law, Banco Hipotecario recognized that by leveraging an Open Banking infrastructure, it could tap into existing solutions rather than reinventing the wheel.

As a result, Banco Hipotecario chose TESOBE to help navigate this new landscape and the Open Bank Project solution to power its first bitcoin-focused hackathon to accelerate the development of innovative banking applications that can satisfy the emergent needs of Salvadoran consumers.



To succeed in developing these kinds of financial applications, Banco Hipotecario outlined the following objectives:


To assist in this project, TESOBE called on a partner in the blockchain space, API3 – a leading first-party oracle solution providing real-world data to smart contracts on blockchains. After assessing a selection of providers, TESOBE and API3 determined that the Qredo Custody Solution and Tropykus Finance lending application were a perfect fit for the bank’s objective. 



Qredo is a decentralised digital asset management platform.


BTC saving & lending platform built on the RSK smart contract platform.


To ensure the best experience for developers, we wanted to provide a unified solution. TESOBE deployed an OBP instance to act as the Bitcoin Bankathon sandbox, then generated and populated the sandbox with localized test data.

In cooperation with API3, TESOBE then deployed an Airnode instance which was connected to the Bankathon OBP API instance. The Airnode was set up to listen for commands on the blockchain, translate them into API REST calls, and post the response back onto the blockchain. In order to link an on-chain address to an off-chain identity, the teams developed a decentralised authentication mechanism: dAuth. 

The OBP Sandbox was then populated with Qredo APIs and Tropykus SDKs were made available.

Once the technologies were integrated, we could present hackathon participants with a unified solution to build their products.


Hackathon Event

With the building blocks of this initiative determined, Banco Hipotecario had only to choose a way forward. In the spirit of innovation, the bank chose to embark on this journey hand in hand with the community.

To succeed in creating a more inclusive financial services landscape for the citizens of El Salvador, we must start driving innovation proactively. A hackathon is like a seed that allows innovation to sprout. Banco Hipotecario is proud to be the first bank to plant this seed to create innovative Bitcoin-based applications that will remove the barriers preventing Salvadoran citizens from accessing financial services in the region.

Celina Padilla

Celina Padilla

President of Banco Hipotecario de El Salvador


TESOBE, API3 and the Sponsors (Qredo & Tropykus) launched a targeted promotional campaign to attract global developer talent, with a focus on local innovators and startups.

On November 19th 2021, Banco Hipotecario de El Salvador launched the Bitcoin Bankathon. 325 participants came together to build innovative banking applications focused on one of five challenges:

  • Build the next neobank: What could a more inclusive Bitcoin-enabled neobank for El Salvador look like?
  • Redesign remittances: How can bitcoin remittances improve the lives of those who rely on money from abroad?
  • Battle climate change: How can banks and crypto companies help citizens of El Salvador unite to tackle climate change and reduce its impact?
  • Empower merchants: How might we empower merchants using open banking data and smart-contracts?
  • Empower women: How can Bitcoin and Open Banking help increase Women’s financial empowerment?

The teams provided technical support over the dedicated discord channel, as well as technical workshops to help the teams get started on their applications. We invited mentors to guide participants and help them build winning applications, and organized informal online sessions to break the ice. 

After three weeks of virtual collaboration and building, hackathon teams started preparing for their final pitch. On December 6th, 7th, and 8th, we invited a limited number of participants to participate in activities and pitch live in El Salvador. 

The event ended on December 8th with live and recorded pitches in front of 9 Judges, who chose 8 winning applications.

Results and Winning Apps


Best Overall Product

  • BitFunding – Neobanking and investment platform for SMEs and Entrepreneurs built on the Bitcoin blockchain.
  • Growr On-Chain – Decentralized lending protocol providing open access to peer-to-peer lending services.

Best use of off-chain data

  • Cardinal – Smart virtual debit card linked to a Bitcoin wallet and supported by a bank to pay with Bitcoin in a regular fashion.
  • Blockchain Carbon Registry – Blockchain-based carbon registry that can help govern emission trading schemes for companies and monitor fulfillment of their emission targets.

Best use of advanced technology

  • PISTO.NETOpen Banking payment system enabling merchants to accept bitcoin by providing digital gift cards to customers, which can be topped up by their relatives abroad to make purchases – even without an internet connection. 

Most visionary concept

  • Tlanetia – Financial inclusion platform enabling women to become financially independent by creating their own community banks funded by their collective savings.
  • Chimera – Set of integrated tools that allow the recording of operations and carbon footprint of micro and small merchants.


The Bitcoin Bankathon was the first Bitcoin-focused hackathon in El Salvador to be launched by a traditional financial institution.

The hackathon enabled Banco Hipotecario to fast-track the development of blockchain-based products and services that will be essential in the forthcoming Bitcoin-enabled landscape. By tapping into solutions already in the market and by inviting the community to contribute their creativity and expertise, Banco Hipotecario greatly decreased the time it would take to comply with the Bitcoin Law and start offering Bitcoin services to Salvadorans. 

TESOBE helped us navigate the new bitcoin landscape and determine the right approach, while the Open Bank Project solution saved us a lot of time and resources. Thanks to this collaboration, we laid the foundation to start offering the next generation of financial services to our customers in El Salvador.

Celina Padilla

Celina Padilla

President of Banco Hipotecario de El Salvador




For more information on the Open Bank Project or if you would like to integrate blockchain services within your offering, please contact us at: | @OpenBankProject | | +49 (0)30 8145 3994

About TESOBE and the Open Bank Project

TESOBE GmbH is an independent company founded in Germany that assists banks in executing effective API strategies. The Open Bank Project started life in 2010 with the vision of enabling all banks to benefit from open innovation, open APIs, and wider access to fintech startups. It quickly scaled into the leading open-source API solution for financial institutions, spanning over 500 banking-specific APIs supported by 11,000 fintech developers worldwide with over 100 global banking customers.

About Banco Hipotecario de El Salvador

Banco Hipotecario is a first-tier national bank with a commercial focus. It focuses on meeting the financing needs of Salvadoran SMEs in several economic sectors, offering a wide range of banking products and services throughout the country.

About API3

The API3 Foundation is a Decentralized Autonomous Organization (DAO)  that builds decentrally governed and quantifiably secure data feeds to power Web 3.0 applications without employing third-party intermediaries. Powered by Airnode-enabled first-party oracles, API3’s dAPIs are fully decentralized and blockchain-native APIs with quantifiable security.