Blockchain Trigger: a tool for automatic smart contract invocation

The ecosystem of blockchain tools for creating decentralized applications is extensive and diverse. In this article, I will describe blockchain Trigger, a service that could be integrated into Waves or any other blockchain protocol.

Blockchain Trigger is a tool that could resolve the issue of high entry barriers for users who want to call a smart contract. In this article about smart contracts, I described the practicalities of writing transparent code and integrating smart contracts into dApps. While setting a smart contract script is quite easy, its invocation remains an open issue:

Every time a user wants to call a smart contract, they need to sign a transaction and interact with the blockchain. This might as well be rocket science to a regular user, and certainly doesn’t help the mass adoption of blockchain technology.

The main functionality that Blockchain Trigger enables is automatic invocation of a smart contract without a user’s involvement. A given condition can be specified for calling a smart contract — for instance, hitting a certain block height, a change to a user’s balance, or reaching a certain point of time in the real world.

When the condition is met, any miner who launches Blockchain Trigger will call the smart contract, instead of a user. Let’s look at three examples of how this tool might be used to achieve unique functionality in a dApp.

Blockchain Trigger-based solution: A user opens a wallet and attaches a smart contract script that corresponds to the relevant rental agreement. The script will automatically be invoked by Blockchain Trigger every 30 days, while the user only needs to make sure that the wallet has a sufficient balance.

Similar mechanics can be implemented in the DeFi space. For instance, payments for Neutrino staking could be executed by a smart contract that is invoked on a daily basis by Blockchain Trigger, sending Neutrino stakers their additional USDN tokens. Similarly, payments to stakers by node owners could be automated with a smart contract invoked by Blockchain Trigger.

This use case could help resolve an issue that recently arose with an existing solution.