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By: on October 21, 2021
Blockchain-based applications are growing in popularity and underscore the decentralized Web3 movement. Simultaneously, web APIs are helping port data and reusable functionality across application types and are driving microservices development practices. So, how do we bring these two paradigms together?
There are many cases where a blockchain-based smart contract may require data updates that only a web API request can fulfill. For example, perhaps the smart contract needs to access the latest price of a given stock ticker. Or, perhaps on-chain activities are contingent on the weather at a particular time. The ubiquity of APIs means there are thousands of helpful features available for the task at hand. Yet, integrating them into Web3 applications is tricky.
Interestingly, the API3 Alliance is making strides to introduce an industry-standard solution to bring APIs to Web3 applications. API3 provides a vendor-neutral standard gateway to apply on top of existing APIs that helps them appeal to decentralized apps. The vendor-neutral API Alliance already consists of many APIs across various verticals and appears to be gaining more traction.
I recently met with API3’s co-founder, Heikki Vänttinen, to learn more about the challenges of introducing traditional web APIs into blockchain development. According to Vänttinen, whereas previous solutions relied on a third-party middleware or ‘oracle,’ the best way to incorporate an API request and response system into smart contracts is through a node operated by the API provider themselves. Such a system could help blockchain-based applications leverage myriad software-as-a-service solutions, essentially uniting the two worlds.
The number of APIs is growing exponentially. As companies reinvent themselves with digital transformation, APIs have become the glue for interconnecting the applications we use on a daily basis. When it comes to APIs, there are a growing number of potential use cases for blockchain—the technology is not just relegated to cryptocurrency; rather, it can power a number of scenarios that require smart ledgers.
Since APIs drive much of the functionality in modern software development, it makes sense that they may be useful in decentralized app development. For example, a blockchain-based decentralized finance (DeFi) app that handles lending and borrowing may want to call an API to collect raw data for a liquidation price, says Vänttinen. Or, a smart contract may wish to acquire the cost of an asset as a conditionality for making a purchase. Hooking into public APIs to check local weather or flight arrival information could affect how smart contracts respond.
There are many use cases for incorporating APIs into a distributed ledger system. However, “blockchain applications are not able to call APIs natively,” Vänttinen explained. The incompatibility is due to the nature of blockchain technology, said Vänttinen, as it requires consensus from multiple parties to maintain the smart contracts. For this reason, blockchain applications require a middleware piece to connect a blockchain node to an API, relaying data responses from outside of the chain.
As Vänttinen described, previous attempts to connect APIs to Web3 architectures have revolved around a third-party middleware node. Yet, externalizing integration responsibility in this way creates a centralized point of failure, which defeats the purpose of a decentralized environment altogether.
Instead of relying on such a dependency, Vänttinen advocates for a “first-party oracle approach,” in which API providers operate a layer in front of their APIs. This enables a request-response mechanism for smart contracts, allowing blockchain applications to initiate API requests from on-chain and incorporate the responses into the contracts. This method retains immutability and trustlessness, which is inherent to the distributed ledger.
One solution enabling such an architecture is Airnode, a Web3 middleware that connects any web API directly to any blockchain application. Companies that have adopted Airnode make up the API3 Alliance, which is “a collective of API providers who have signed up to enable this first-party use of their API for Web3 applications,” said Vänttinen. “Adopting Airnode is a pledge from API companies to make their API blockchain-compatible.”
The API3 Alliance is one significant initiative aiming to extend the capabilities of smart contracts and blockchain applications. This could enable such environments to call an API to send a text message or email, or grab sports scores, collect maps data and so on. Thus far, participating APIs in the API3 Alliance come from sectors such as agriculture, biotechnology, communications, open banking, insurance, supply chain management and many others. The initiative also accepts applications from API providers that want to join the marketplace.
So, what are the benefits of embracing an industry-standard middleware for web-API-to-blockchain connectivity? Well, according to Vänttinen, it is the best way to enable complex off-chain computation. Enacting intricate computing on the chain is quite resource-intensive, resulting in high transaction fees. By extending particularly complicated calculations externally, blockchain applications could reduce operational overhead. “The industry is long overdue for connection between the real world and blockchain,” said Vänttinen. (By real-world, I assumed he meant other architectural styles that pre-date blockchain.)
Having a standard implementation could also reduce the development burden for the API provider to support nuanced technologies. Whereas other solutions would require someone in-house to operate blockchain nodes, Airnode is more of a plug-and-play API gateway that could be deployed on AWS as a Lambda function, Vänttinen said. This usability makes it easy for API-based services to appeal to Web3 applications, thus quickly opening a new potential growth segment.
Of course, Vänttinen admitted, the concept of syncing with off-chain processes is still at a very early stage. There are competing philosophies about how to address it on the market, and some foundational issues have not yet been resolved. For example, most efforts have focused on Read operations to acquire raw data. The next step will be having the middleware ‘oracle’ incorporate off-chain Write capabilities, too. Furthermore, more PubSub-like formats will be important to enable event listeners capable of reactive qualities.
The Web3 trend is bringing more decentralized, blockchain-based applications to fruition. But, such applications can’t operate in a closed-off world. To experience the full breadth of digital possibilities, they’ll likely need to figure out how to incorporate off-chain computations and mesh with alternative communication software libraries. Naturally, this will require integrations with web APIs, which have become an important method of cloud-based communication.
The API3 Alliance is “here to propose a solution to the API connectivity problem for Web3,” said Vänttinen. “When a data provider is blockchain-compatible, you can apply the reputation of the data provider in this decentralized data feed … The importance of this becomes more clear when you talk about connecting off-chain services and microservices with smart contracts.”
Airnode and the surrounding API3 Alliance is one initiative spearheading the connection of APIs and smart contracts. But, this is just one method in a maturing field. What do you think about bridging the two paradigms? Comment on your experience below!
Filed Under: DevOps and Open Technologies, DevOps Culture, Features
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