What is Chainlink? (LINK)

Chainlink is a cryptocurrency aiming to incentivize a global network of computers to provide reliable, real-world data to smart contracts running on top of blockchains.

If you’re unfamiliar, smart contracts are agreements programmed to execute if and when certain conditions are met. To date, smart contracts have been used for everything from creating novel crypto-financial products to developing new crypto assets.

However, an issue that has persisted is that most smart contracts need to rely on some kind of external data source to properly execute their terms.

For example, smart contracts seeking to replicate bonds or insurance agreements may need access to APIs reporting on market prices or Internet of Things data.

Chainlink was created to address this issue by incentivizing data providers (called “oracles”) to act as a bridge between blockchain smart contracts and external data sources.

Every oracle within the Chainlink network is incentivized to provide accurate data since a reputation score is assigned to each. Further, when nodes follow the software’s rules and provide useful data, they are rewarded in Chainlink’s cryptocurrency, LINK.

Arriving amid a crowded field of projects in 2017, the Chainlink team has so far been able to deliver on its vision, expanding efforts beyond Ethereum (ETH) amid a surge in market activity.

As of 2020, Chainlink is seeking to support all blockchain-based smart contract networks.

Users seeking to stay connected on the current development status of Chainlink can follow its official project tracker for up-to-date details.

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How does Chainlink work?

To facilitate communication between its users and external data sources, Chainlink divides its execution process into three distinct steps.

1. Oracle Selection – First, Chainlink users draft a service-level agreement (SLA) that specifies a set of desired data requirements. The software then uses the SLA to match the user with oracles that can provide the data. Once the parameters are set, the user submits the SLA and deposits their LINK cryptocurrency in an Order-Matching contract, which accepts bids from oracles.
2. Data Reporting – This is where the oracles connect with external sources and obtain the real-world data requested in the SLA. The data is then processed by the oracles and sent back to contracts running on the Chainlink blockchain.
3. Result Aggregation – The last step involves tallying the results of the data oracles collect and returning it to an Aggregation contract. The Aggregation contract takes the responses, assesses the validity of each and returns a weighted score, using the sum of all the data received, to the user.

Architecture

The Chainlink blockchain is powered by three types of smart contracts.

• Aggregating Contracts – Collect data from oracles and match the most accurate results with the smart contract that needs them.
• Order-Matching Contract – Matches a smart contract’s service level agreement (SLA) with the best bidding oracles.
• Reputation Contract – Verifies an oracle’s integrity by checking its track record. This includes factors such as the total number of completed requests, average response time and amount of LINK cryptocurrency the oracle has staked.

However, Chainlink also interacts with oracles that do not operate on its blockchain, and that are independently responsible for collecting the real world data requested by the contracts.

The nodes are made up of two components:

• Chainlink Core – Chainlink Core is responsible for reading newly filed SLAs and routing assignments to the Chainlink Adapter.
• Chainlink Adapter – Acts as the bridge between the node and the external data. The adapter can read and process the data and write it to the blockchain.