Chainlink (LINK)

• Short explanation by Messari:

"Connecting smart contracts to reliable off-chain data oracles. ChainLink is blockchain middleware that decentralizes data oracles enabling anyone to become a data provider in a reputation-dependent information network."

Chainlink

Type	Oracles. ERC677 Token
Total supply	1.000.000.000

Basics

• Launched by the San Francisco fintech company SmartContract in June 2017. Currently based in the Cayman Islands.
• External data for contracts.
• Mainnet launch on Ethereum was on 30 may 2019.
• Short explanation by Messari:

"Connecting smart contracts to reliable off-chain data oracles. ChainLink is blockchain middleware that decentralizes data oracles enabling anyone to become a data provider in a reputation-dependent information network."

• Longer explanation by CMC:

"Chainlink (LINK) is a decentralized oracle service, which aims to connect smart contracts with data from the real world. Since blockchains cannot access data outside their network, oracles are needed to function as data feeds in smart contracts. Oracles provide external data (e.g. temperature, weather) that trigger smart contract executions upon the fulfillment of pre-defined conditions. Participants on the Chainlink network are incentivized (through rewards) to provide smart contracts with access to external data feeds. Should users desire access to off-chain data, they can submit a requesting contract to ChainLink’s network. These contracts will match the requesting contract with the appropriate oracles. The contracts include a reputation contract, an order-matching contract, and an aggregating contract. The aggregating contract gathers data of the selected oracles to find the most accurate result."

Audits & Exploits

• Bug bounty program can be found here. Max payout is $5000 (29-6-2020).
• Blockchain Security DB (29-6-2020) shows 5audits. The latest was in 9-2019.

Hacks/Exploits

• From The Block (4-9-2020):

"At least nine Chainlink node operators suffered an attack on Sunday that resulted in the draining of about 700 ETH from their wallets, The Block has learned. The attack exploited the way in which nodes respond to queries and involved the use of a token tied to network transaction costs. Chainlink confirmed the attack and described it as a “failed attempt” to spam the network."

Governance

• From this (very bullish article) about Chainlink, in which it explains how smart contract users/developers can chose their level of decentralization and security (29-10-2020):

"Levels of Decentralization:

When a smart contract creator uses the Chainlink network for its services, it must first select the amount of nodes it wants to use. For example, having one node fetch data for the contract will likely be cheaper, but comes with more security risk, whereas having 1000 nodes service the same contract will give the contract far greater trust and security.

Distributing Sources:

One of the ways a smart contract creator can increase trustless connectivity of the smart contract is by having nodes fetch data from several sources. For example, a node could get market-pricing data from Bloomberg, Yahoo Finance, and Reuters.

Distributing Oracles:

Another way it can increase trustlessness in the connectivity layer of the smart contract is by having multiple nodes work on the contract. One way this could work is for all the nodes to get data from the same source, which is important when there is only one source of data. This would insure against the one and only node being a bad actor or getting hacked, since there are other nodes to back the contract up. Another way is to have multiple nodes get data from multiple sources.

Aggregation:

The smart contract creator can also choose an aggregation method for the data fetched by the nodes, such as using an average from all the sources, tossing out the outliers, or weighting different sources more than others. In reality, there can be all kinds of aggregation methods. It’s ultimately up to the smart contract creator to choose what they want.

Penalty Payments:

The smart contract creator can also choose how much collateral they want the node to stake in order to get the privilege to solve the contract. This collateral acts as both a penalty payment and insurance on the contract in the event that the node acts in a malicious or unprofessional way, specifically if their data feed is inconsistent with the data given by other oracle nodes working on the smart contract. The malicious node will have to pay the smart contract creator the amount of collateral that was agreed upon in the beginning of the contract if their data feed is a clear outlier. Low value contracts might not request as much collateral, but high value/high importance contracts will likely want larger amounts of collateral staked to insure the node performs its job to the highest standards.

Reputation:

Another security check on nodes is having a reputation system that rates nodes based on certain criteria such as the total number of assigned requests, total number of completed requests, total number of accepted requests, average time to respond, and amount of penalty payments. What this does is keep nodes acting in an honest manner because if they do not, they are subject to receiving bad ratings by other users, which are then seen by future customers. A bad rating would cause the node to lose out on potential revenue earned by servicing upcoming contracts. This is likely to be done by third parties, at least initially.

Certification Services:

Finally, another proposed security check is for the Chainlink team or some outside third party to give endorsements of high quality oracle providers. They could do this by monitoring network statistics in order to locate nodes they found most reliable. This is not something that is mandatory, but more of an optional feature to increase security on the system."

Decentralization

• From Our Network #23 (30-5-2020)

"Zooming out and looking at the distribution of LINK payments paid to each active Chainlink node since mainnet launch in May 2019 gives some interesting information on the evolution of the Chainlink network. The first observation is that the network has been continually decentralizing over time. First only beginning with three nodes (Chainlink team, LinkPool, and Fiews), the network has since grown to over 30 active nodes, a 10x increase in decentralization.

The overall percentage of LINK payments paid to the Chainlink core team’s node has also drastically lowered over time. Initially beginning at 33.33% of the total daily payments, it has since lowered to only 1.34%. Additionally payments have become more variable in the last third of the chart due to the transition to a deviation based schedule. Additionally notice how each node is paid differently, this is due to the fact that not every Chainlink node is not equal in quality and thus do not serve the same amount of oracle networks."

Token

ICO

• The following comes from this analysis (22-1-2018):

"The ChainLink ICO was quite hyped up in a certain community – 4chan’s /biz/. Failing to spark the marketing bullwhip outside isolated tech circles on 4chan and Reddit, ChainLink’s ICO wasn’t exactly the most well-known, despite selling out. There was some post ICO drama regarding tokens not being paid out correctly, and the ICO didn’t even use smart contracts, despite ChainLink being a product of Sergey’s Smartcontract.com platform.

A rather beautiful part of the ICO distribution was the presale ICO, with a minimum amount being 100 ETH each. Well, that’s not the beautiful part – because few people aside from institutional investors could afford it (remember, this is September 2017, the price of ETH is around $300 each). So a bunch of 4channers from /biz/ pooled up their money and shared ICO links to participate in the presale.

ChainLink’s price didn’t continue to spike after the token release, like anticipated. After a parabolic initial increase, the value dropped and Chainlink hype subsided. The people who made posts about the ChainLink ICO being a scam due to its rather incongruous set up came out of the woodwork laughing at everyone for buying into it. ChainLink only continued its growth during the December 2017 alt bull run. It’s still never reached its BTC all time high of 10000 sats achieved in October. In cryptocurrency terms, holding a coin that doesn’t grow for several months is unacceptable, and most investors would have exited LINK a long time ago.

The various flavours of ChainLink FUD memes that have appeared since then:

ChainLink just got “shadow forked” for insiders

Jason Parser joined the dev team (and may also be Rory’s dad)

The ChainLink office is a Chinese nail salon/iPhone repair shop

Sergey Nazarov eats too much McDonalds

“Link marines” and “stinky linkies” who hold LINK

• According to this blog (2017) there were 3 mistakes made in the ICO:

1. "Communication. ChainLink sent me only one email and it was littered with enough mistakes that I thought it was from a scammer at first, so I double checked with other people who had signed up for it and verified it was legit.
2. Smart Contracts. Ironically, for a company that has a working product designed to make better smart contracts, the deposit address wasn’t using smart contracts. So instead of automatically refunding everyone that was over the hard cap, ChainLink will have to manually refund everyone. 
3. Using Fiat as a hard cap. Sergey Nazarov statements on Reddit show a lack of understanding of the crypto market. He keeps insisting that the price of ETH rose from the pre-sale and that ethically it would be unfair for him to short pre-sale participants. The problem is why are you using fiat when you are doing an ICO in ETH?"

It also mentioned 4 reasons Chainlink might have been a scam:

1. "Late whitepaper. It is very unusual to do a pre-sale before even releasing their whitepaper but that was exactly what ChainLink did. In fact, their whitepaper was so late that they pushed back the ICO an entire week to compensate for it.
2. Pre-Sale Pooling. Their pre-sale was for high cap individuals only but in direct contradiction of the contract, people formed pools to buy into the pre-sale. Not only that but because of the pooling, several groups of people were able to bypass the 100 ETH limit. No consequences were ever seen and only some discussions were offered on how to send back the ETH that went over the limit.
3. Silence. After pre-sale ChainLink went silent, with only a few peeps about their whitepaper undergoing scientific review. Eventually, they went completely silent with the only communication coming from the ICO email.
4. No KYC. Despite prohibiting USA, Singapore and Chinese residents from participating ChainLink just required checking a little box proclaiming you weren’t from any of those nations."

• Sergey gave a Reddit response (20-9-2017) on their ICO choices:

"In order to include more people, we considered raising the dollar cap like other projects, but that seemed like something that would be strongly disliked by the larger community, as it has been with other projects.

In choosing to keep our $32MM dollar cap, in conjunction with the rise in ETH price, we ended up giving all token sale participants approximately 30% more LINK per ETH than we originally planned when pricing the token sale at a lower price back in July. Instead of the 2000 LINK per 1 ETH initially planned we ended up giving our token sale participants 2600 LINK per 1 ETH, to their benefit, allowing them to capture the gains in ETH price, by us choosing to stay at our $32MM cap. We feel that sticking with the cap we mentioned earlier was indeed the more ethical thing to do, even if it meant we raised less ETH.

In order to reduce the effect of a rising ETH price before the crowdsale, we did try to set the dollar rate for ETH back on Friday September the 15th to an average of $220, based on the recent drop in ETH price during that time. After listening to feedback from the community about this being an unpopular and uncommon decision, we chose to listen to their requests for setting the ETH price closer to the crowdsale date. Since Friday, the ETH price has had a ~30% increase to $285, which together with us maintaining a $32MM cap to the benefit of our token sale participants, led to less LINK being available for sale per ETH. We did try to work through this before the crowdsale, but the setting of an ETH price even a few days before the crowdsale is something that the larger community seemed against, leading to us adopting their suggestion of setting the ETH price closer to the crowdsale date.

We previously stated that the presale would be part of the crowdsale, which was something that the community in our slack wanted us to comment on back in the early days of the token sale, and which was repeatedly mentioned in our slack. We would have been glad to keep the presale entirely separate from this $32MM, because that would have allowed us to raise much more ETH in total, but we made it part of the crowdsale based on what the community seemed to expect from us.

As I look at this now, it seems more transparent to include the presale amount in the crowdsale total, because then there isn't any other amount raised elsewhere as part of the token sale. If we had raised a separate presale amount, then that would add up to much more than the $32MM here, for the same amount of 350MM LINK tokens. I'm not sure why it would be clearer to say we have a seperate presale that isn't part of the crowdsale. It seems to make sense that people would be interested in the total amount raised for the distribution of all the public sale tokens."

The community responses were less than positive.. Most rants included that the post did not respond to the initial critiques. Many claimed he lied, that the ICO was a 'terrible experience' and people overall complained about the fact that the ICO was not done by smart contracts. Quite some were outraged because their ETH got rejected and now they had to wait for refunds (since it was not done by a smart contract). However one user commented:

"Edit: u/sergeynazarov and the ChainLink team did an amazing job with handling the aftermath since they returned funds within hours (including the cost of their transaction fees). Everyone makes mistakes, but we just have to learn from them."

• One ICO review also mentioned as a concern: "The team has not been very responsive to community's questions for the past two weeks. This may drive some potential participants away as they may prefer a team with more transparency."

Utility 

• The token get's its value from supply and demand of being used. And because providers need to buy collateral to stake. Which will be taken away if they provide bad info. And this also creates token value because these staked coins are locked up until the provider decides not to be a provider anymore.

Token Details

• ERC677 token on ETH

• "Even non-data providers can benefit from this since there are staking services popping up for Chainlink which allow LINK holders to loan their tokens to people operating data nodes in exchange for a portion of the profits. These staking systems are effectively high interest savings accounts, which will see returns upwards of 5%."
• From this article(9-10-2019):

"According to the developers, 35% of all LINK tokens will go to node operators to incentivize the ecosystem with an additional 35% sold in the public token sale.

The final 30% of the total LINK tokens will remain at the company for continued development and staff payments."

• By Messari:

"LINK’s token offering launched September 19, 2017 with a $32 million hard cap. The pre-sale offering sold LINK at $0.09 per token with a 20% bonus depending on when the investor participated. The subsequent public sale sold LINK at $0.11 per token. Combined, both sales dispersed 350 million LINK. A separate 650 million tokens were made unavailable and are allocated for building data provider incentives, protocol development, and smart contract platform partnerships. LINK has not released specifics on budgeting or operating expenses. No public information is available for equity rounds held by LINK’s parent company, Smart Contract ChainLink LTD founded in 2017 and currently based in the Cayman Islands. Since September 2017, around 15M LINK have been transferred from one of the company ERC20 address. Chainlink has not provided any information in vesting schedule and no smart-contract restriction has been found for he company holdings"

Other

• Moved 700k$ LINK (7-2019) from a dev wallet to Binance during a massive LINK bullrun.
• Sold another 30 million dollars worth (8-2019), saying they needed the funds for development.

Coin Distribution

• From Our Network #17 (19-4-2020):

"Binance and Coinbase together now account for over 40% of the circulating supply of LINK. LINK’s distribution across the two exchanges have just recently come to parity with each other with both exchanges holding 70M LINK. It should be noted however Coinbase does not make their wallet addresses public, so this information was aggregated by tracking particular wallets that exhibited identical robotic accumulation behavior which started at the same exact time as the Coinbase listing."

• Some (7-2020) have accused Chainlink of splitting up its holdings over more accounts to create the view of decentralisation.
• From Our Network #51 (18-12-2020):

"During the overall period, the Chainlink network has considerably increased its wealth concentration, with 90% of the supply being currently held by only 0.08% of all wallets; earlier this year this figure was above 0.3%."

• From Crypto Briefing (19-1-2021):

"125 wallets held 81% of the total supply. Chainlink node operators hold 35% of the supply, the team holds almost 25%, and exchanges hold 16%. No wallet outside of teams, nodes, or exchanges holds over 1% of funds. The author’s findings show that wallets holding more than 1% of the total supply account for 66.6% of the supply. The distribution for wallets holding over 1% is as follows:

1. Smart contract for Chainlink node operators: 35%
2. Chainlink team: 24.8% across five different wallets
3. Binance: 3.4%
4. Aave LendingPoolCore: 2.7%

Exchanges hold 16% of the total supply. 35% of the funds are held in a smart contract that will be paid out to nodes as an incentive and the team holds 24.8%. The team holds enough LINK to manipulate price action, they’ve only sold 5% of the total supply over the last 3 years, moving from 30% to 25%."

Tech

• Whitepaper can be found here (4-9-2019). Second Whitepaper (13-4-2021).
• Code can be viewed [insert here].

 How it works

• Done by Messari:

"LINK’s decentralized network of introduces three approaches to ensuring against faulty data inputs and ameliorate other vulnerabilities associated with single trusted oracles.

Distributing data sources and curating verified data via majority voting prevents reliance on a single data sources. LNIK also distributes oracle selection by aggregating oracle data and ordering historical oracle trustworthiness. Third, LINK introduces hardware components like Intel’s Software Guard eXtensions to protect the integrity and confidentiality of supporting applications.

ChainLink also introduces a reputation and certification system to catalog and display oracle performance for user evaluation. Oracle security profiles include number of assigned requests, number of completed requests, average response time, etc. LINK is used to pay node operators for data retrieval from off-chain feeds, formatting data into blockchain-readable formats, and good data-retrieval up time.

LINK was originally built on Ethereum with plans to interact with all smart contract networks like EOS, HyperLedger and RootStok."

• The core architecture of Chainlink is based on four fundamental components:

· External Data: This might represent an API or data fee containing relevant information to a blockchain programmable asset.

· Chainlink Node: This is the off-chain middleware operates between the blockchain and external data sources, which provides real-world data and fulfills the requests from requester contracts. The Chainlink node handles jobs, tasks, scheduling, and signing transactions for the blockchain. The Chainlink node runs through a specified set of sequential processes and includes a number of core adapters which give it support to read and process data, and write to the blockchain.

· External Adapter: This component allows for additional functionality outside of what is supported by the default Chainlink adapters. Data validation and mapping are classic scenarios for external adapters. Functionally, external adapters can be seen as serverless routines that complement the core functionality of an existing Chainlink adapter.

· Blockchain Node: This component is responsible for monitoring a specific blockchain and allows the Chainlink node to look for specific events to occur to initiate a job.

• The following comes from this article (30-5-2019):

"Chainlink Ecosystem

Chainlink clarified there are three types of projects that the ecosystem: Data providers, platforms/blockchains, and projects that use Chainlink oracles. Although Chainlink refrained from pointing to a comprehensive list, they pointed to a Decrypt article which mentions many collaborators and projects. There is a lot of speculation in the industry, they added, and they only confirm when official. Chainlink provides more than the technical infrastructure here -- they also provide an instance of this infrastructure, with vetted data providers onboarded. Chainlink emphasized that they work with top data partners for officially created adapters such as crypto price data, supply chain, etc. Essentially, there are two layers of selection there: One on the oracle network, and one within each oracle. Users can choose which oracle(s) to use in the oracle network, and oracle nodes can choose which external services to connect to.

Essentially, oracles will act as data hubs, with data flowing in and out of them. How will the different data providers and data streams be cataloged, integrated, and managed? And what about issues related to data freshness, correctness, and performance?

Data selection and schema matching

Chainlink currently operates with a schema system based on JSON Schema, to specify what inputs each adapter needs and how they should be formatted. Similarly, adapters specify an output schema to describe the format of each subtask's output.
Schema management at scale with data coming from various domains and sources is a sufficiently researched and documented topic, but that does not make it easy to deal with in practice. Especially when using JSON Schema, which is not the most advanced solution when it comes to schema management.

So what happens when there is no sufficient metadata on the data flowing through Chainlink? Not to mention, even sufficient metadata can be erroneous / misleading. What happens if i connect a data provider and claim it's about topic A, but others say it really is about topic B, or C, or D and E? Chainlink says this is where decentralization plays a key role in the oracle problem:

"Just like how smart contracts are secure because they're ran on multiple machines (blockchain nodes), you can secure the inputs to your smart contracts by having that input retrieved by multiple Chainlink nodes.
So if you're a requester, and you want data from a particular API DPA, you define how many Chainlink nodes you want to retrieve that data. To further decentralize your inputs, and if there are additional data providers with the same topic of data, you could have additional Chainlink nodes retrieve from another API DPB to assist with validation."

However, we would argue that while that does indeed address the topic of data source selection, it does not address that of schema matching: The terms used to describe what DPA and DPB is about could be different, and yet their data could be about the same thing. Based on JSON Schema, without a mechanism to align the metadata in place, nobody would ever know.

Data flow

From a data architecture perspective, Chainlink looks like a data hub through which data will flow transiently. However, a published list of use cases, interacting with databases and data in the cloud is mentioned.

We wondered whether there are implementations of such use cases to show for today. Plus, if this takes off, the amount of data flowing through Chainlink will be considerable. Would Chainlink consider storing any of that data in the oracle, for example for caching?

Chainlink's view is that they like to think of it as an on-chain protocol that allows smart contracts and node operators to work with one another in a trust-minimized way. The ChainLink oracle acts as a data hub, enabling data source selection on 2 levels: oracle and external data sources.

"This means that any endpoint that a node operator can access can be used by a smart contract through our protocol. We have a number of working implementations that give smart contracts the ability to retrieve data from authenticated data sources. Storing or caching data within the oracle is not currently a consideration since there are a number of security concerns associated with that. Data providers already have the facilities to store data long-term, and have the history and reliability of providing that data."

And what about the other way round? If a smart contract wants to send data to an external source, rather than store it on the blockchain, can Chainlink do this?
A Chainlink node can relay information from a smart contract to an external source. However, this would introduce an array of issues, as storing data in an external system means the tamper-proof aspect of data storage on the blockchain no longer applies."

Upgrades

• From CoinDesk (29-8-2020):

"Sergey Nazarov and Juels Ari have begun drafting a second Chainlink white paper, according to a phone interview with the pair."

• From EthHub (2-3-2021):

"Off-chain reporting (OCR) is an upgrade that reduces the on-chain gas costs by up to 90% for Chainlink oracles."

Staking

• Is not yet (7-2020) fully live. When asked about it (19-7-2020) in their Telegram group, the admin sends people to an article from 10-6-2019 in which it states:

"In order for staking in Chainlink to be possible, two main aspects of the Chainlink software need to be complete, these are commonly referred to as the Penalty and Deposit contracts. These contracts contain the logic that allows smart contract creators to specify collateral requirements and the ability for nodes to be penalised in the event they don’t fulfill their accepted tasks. The Chainlink team do not typically work to set time frames, choosing to release the work when they feel it has met their high standard, so it is difficult to say exactly when staking will be available. However, you can track the teams progress and what they are working on here."

• From Eric Wall (1-5-2021):

"Now, LINK marines as well as the Chainlink team has come up with a cringeworthy term called “implicit staking” which tries to argue basically the following: “Hey, nodes actually do have something at stake! Their future LINK payments!”"

Validator Stats

• There are 103 nodes online according to market.link and 144 oracles according to reputation.link as of 9-12-2020. About 25% of these get actual 'jobs'. These are almost all 'approved' nodes by Chainlink.

LinkPool

• From their blog (10-6-2020):

"We started LinkPool in 2017, shortly after the Chainlink ICO. We first realised the necessity for a staking pool for Chainlink due to the higher than normal technical requirements for this type of staking, but we also wanted to help grow the ecosystem by building tools and services for Chainlink. We received great support from the community and decided to hold a small crowdsale of 1000 Ethereum for 1000 LP tokens allowing us to develop LinkPool to the highest standards. We sold 700 Eth worth and distributed the remaining tokens so the ratio was about 1:1.4 ETH/LP, you can read more about that in this article."

Scaling

• From Daily Gwei (25-9-2020):

"[[[Optimism]] has] plans to work with Uniswap and Chainlink to bring their services to layer 2."

• From Decrypt (16-10-2020):

"Former BitGo CTO Ben Chan has joined Chainlink to build layer-2 scaling solutions. The Threshold Signatures scaling solution will aggregate data and send it to Chainlink customers in a single transaction."

Interoperability

• From this article, which is highly biased towards Chainlink (8-8-2020):

"Through modular external adapters and external initiators, Chainlink nodes are able to monitor data requests and deliver off-chain data to any blockchain environment directly, meaning there is no reliance on lite clients or external third parties with questionable incentives/accountability. Thus, Chainlink nodes are able to natively support any blockchain, DLT, or layer 2 solution that exists today or into the future, including chains that have limited smart contract capabilities like Bitcoin where such a lite client could not be hosted."

Other Details 

• Using the 0x protocol.

Oracle Method

• From this Tezos forum (30-4-2020):

"ChainLink’s reference price feeds rely on a set of trusted parties to provide asset prices to the Ethereum blockchain. ChainLink also offers a service that allows users to request alternate off-chain price data from trusted oracle providers or, alternatively, set up a network of oracles themselves. ChainLink provides free access to reference price feeds for the ETH/USD and BTC/USD pairs (as well as many others). These feeds rely on a set of 21 trusted parties to submit reference price data. The ETH/USD pair updates every 0.5% deviation in price and has a heartbeat of 2 hours. The BTC/USD pair updates every 1% deviation in price and also has a heartbeat of 2 hours. Unlike MakerDAO, ChainLink does not have a decentralized governance process to determine participating parties in its reference price feeds. ChainLink itself is responsible for adding/removing parties from the system, centralizing control of the reference oracles.

ChainLink allows application developers to run their own ChainLink node or request other off-chain data, but requires payment in the LINK token. LINK is an ERC-667 token that implements a custom function that allows for the transfer of data along with token transfers. This mechanism is used to query and transfer resulting data from ChainLink nodes to on-chain smart contracts. If an application developer wishes to query non-reference data using Chainlink, they can either run their own ChainLink node, or query one of ChainLink’s trusted nodes. Each node that is queried charges the requester a predetermined amount of LINK. Requesters can call multiple nodes to achieve the desired degree of decentralization, but are charged for each query they make.

ChainLink gives developers the option to run their own ChainLink node that responds to requests, but requires these developers to buy and send the LINK token to themselves for each request they make. ChainLink will also be establishing a whitelist for all on-chain reference price data (although it is currently free). The ChainLink organization will control all changes (additions/deletions) to this list."

Oracles

• At the mainnet launch (30-5-2019) Chainlink started out "with three endorsed oracles, including its own. The other teams are Fiews and LinkPool. These teams have been running a Chainlink node on the Ethereum test networks for around a year, and have assisted with the development of the Chainlink node. Chainlink noted they will also have an on-boarding process for endorsed Chainlink nodes to be listed in official documentation."
• Amberdata has partnered to be an oracle. Announced: 23-5-2019
• A total of 62 oracles are mentioned in their own docs (as of 12-2019). These include Fiews, LinkPool, Chainlink and Stake.Fish. Amberdata is not mentioned.
• T-Systems Multimedia Solutions has become a node operator (27-7-2020).
• Framework Ventures is an integral node operator (27-8-2020).

Reviewed Node Operators

• Stake.fish (26-7-2019):

"As a Reviewed Node Operator, Stake.fish will be listed in Chainlink’s official documentation and the Chainlink Explorer (used for tracking activity on the decentralized oracle network). On the Chainlink platform, running a node allows it to provide external data directly to smart contracts.

In addition to supporting the oracle network, the Stake.fish team intends to help grow the Chainlink community by attracting more developers and other qualified professionals."

• In their official docs we can see (as of 12-2019) some of the names that are also mentioned in their partnership lists, which means they are still working together, most are part of the testnet . Some also on the mainnet.

Price Feeds

• From Our Network #12 (12-3-2020):

"The diversity of price feeds live on mainnet and their respective sponsors have expanded from 10 price feeds supported by two projects to now 29 price feeds supported by 10 projects, a growth of 2.9x in price feeds and 5x in sponsors in the past three months. The BTC/USD and ETH/USD price feeds consume such a high percentage of Chainlink’s bandwidth due to its higher relative decentralization (20-21 nodes vs 7-9) and more sensitive update frequency (every 20 minutes and 0.5% deviation).

The ETH/USD price feed has shifted from a single sponsor to three independent sponsors. This reduced the costs experienced by the original sponsor by 66% with no reduction in node payments. As more projects support a common oracle network, the costs for each individual sponsor goes down, creating a public good model where security can be higher than what a single project could reasonably afford on its own."

Provable Randomness

• From CoinDesk (12-5-2020):

“A lot of applications can’t exist in a trustless way without randomness,” Nazarov said in an interview.

In short, smart contracts will send a seed to a Chainlink oracle which will generate a random number using Chainlink’s VRF. The resulting number, broadcast back to the application, can be verified as random based on the oracle’s public key and application’s seed, Chainlink said in a blog post.

PoolTogether is the first subscriber to Chainlink’s VRF. PoolTogether will now switch from its centralized randomness selection method to Chainlink’s VRF for decentralized randomness."

• From The Defiant (13-5-2020):

"[It] allows applications to prove they can generate values in a random way. Chainlink says its system can guarantee randomness is provably fair and equally uncertain to all contract participants with cryptographic proofs, while also reducing the risk of exploits."

Proof of Reserve

• From EthHub #143 (7-12-2020):

"Chainlink Proof of Reserve, on-chain reference feeds that provide smart contracts with the data needed to calculate the true collateralization of any on-chain asset backed by off-chain reserves."

Privacy Method

• From their blog (16-1-2020):

"Two privacy solutions have initially been introduced for Chainlink, differentiated by the developer's needs and trust assumptions. TEE-based oracles can be used to hide oracle queries from the oracle itself, removing the possibility of them leaking sensitive information (assuming you trust the hardware). Users could also use Chainlink to connect with off-chain computing environments like the trusted compute framework (TCF) as part of the Hyperledger Avalon project.

The other more recent non-hardware based approach is Mixicles, which uses oracles to create privacy by decorrelating the inputs and outputs of a smart contract. Following this protocol design, the oracle retrieves data and makes a true/false determination (switch) on the data off-chain. The determination is then relayed to a mixer that issues designated outputs based on that oracle input. The basic premise is that the state change (determination) is decorrelated publicly on-chain form the output payment for settlement. For even deeper security needs, users can use TEE-based oracles or DECO in tandem with a Mixicle to hide the switch from the oracle. For a more thorough understanding, please read the research paper or our less technical blog post."

Compliance

• From CoinDesk (6-8-2021):

"In addition, a new anti-fraud network will run parallel to the Chainlink cross-chain bridge, and monitor every single signature, transfer and addition or reduction of a node, Nazarov explained. The anti-fraud network has the ability to lock the bridge at any moment completely unilaterally, he added. “This creates a critical layer of risk management and anti-fraud management,”"

Their Other Projects

• Town Crier was bought by Chainlink. It was developed by the same person who they bought DECO from.

• From CoinDesk (29-8-2020):

"Acquired Cornell University’s privacy oracle solution DECO for an undisclosed amount. DECO was co-created by Ari Juels, former chief scientist at digital security firm RSA. He will also join Chainlink Labs under the same title. Juels told CoinDesk this privacy is possible through DECO’s incorporation of zero-knowledge proofs"

Cross-Chain Interoperability Protocol (CCIP)

• From CoinDesk (6-8-2021):

"Chainlink also announced a Programmable Token Bridge that will be built atop the CCIP. The bridge can be used to send tokens and computational commands to any blockchain network, opening the door to more advanced cross-chain applications. Celsius announced Thursday it has committed to using the CCIP. Under the hood, Chainlink’s CCIP leverages something like multi-signature security, Nazarov said, but done in a way that efficiently aggregates signatures from hundreds of reliable Chainlink nodes.

In addition, a new anti-fraud network will run parallel to the Chainlink cross-chain bridge, and monitor every single signature, transfer and addition or reduction of a node, Nazarov explained. The anti-fraud network has the ability to lock the bridge at any moment completely unilaterally, he added. “This creates a critical layer of risk management and anti-fraud management,”"

Keepers

• From CoinDesk (6-8-2021):

"Chainlink is expanding its services to include decentralized off-chain computation – a job done by a network of node operators known as “Chainlink Keepers.” Chainlink keepers will be selected from the network’s existing pool of reliable node operators, said Nazarov, and the profit they earn will ensure they provide computation at any level of congestion or cost scenario. Going forward, more enterprise-grade keepers will be added to the network, like Deutsche Telekom’s T-Systems."

Roadmap 

• Can be found [Insert link here].
• From this interview with the CMO (29-9-2020):

"Moving forward, three of Chainlink’s key goals and technical objectives are to scale our oracle networks through an off-chain aggregation technique known as threshold signatures, introduce economic incentives for node operators, our term for reputational staking, and to become truly chain-agnostic by integrating with a variety of smart contract platforms.

We also have big plans in the work for DECO, the privacy-preserving computation system we recently acquired from Cornell University. As on-chain contracts and financial products grow more complex, they will need oracles that can accommodate unique needs, particularly access to data that needs to remain confidential. Our acquisition of DECO positions us to continue growing towards the future by allowing smart contracts to use sensitive data in on-chain transactions while keeping that data completely confidential."

• From Decrypt (15-4-2021):

"The new whitepaper, titled Chainlink 2.0: Next Steps in the Evolution of Decentralized Oracle Networks, builds on the foundation the startup has established to reveal a new “MetaLayer” architecture for hybrid smart contracts; “the place where all of the coordination happens,” said Nazarov. “Hybrid smart contracts are about combining blockchain smart contract application capabilities, and the off-chain world’s proof and data and computations,”. Hybrid smart contracts will lead to advanced Decentralized Oracle Networks—which the whitepaper terms “DONs”—that serve as an off-chain computation layer, anchored to blockchains for security. “We're evolving from simpler oracle networks into more advanced Oracle networks called DONs, and then a large collection of DONs will form a MetaLayer,” explained Nazarov.

The MetaLayer—and even its definition—is still a work in progress. But, essentially it’s where hybrid smart contracts connect to a payment network, an ad network, or any other outside system, and coordinate these interactions. The MetaLayer allows for more off-chain resources; higher-frequency updates for price feeds and better cost-efficiency and security for NFTs and new applications, such as decentralized identity services. “There's going to be a set of Chainlink identity tools, where users can get identity data into their smart contracts, which is going to allow them to build smart contracts that comply with regulations, and that are usable by enterprises,” said Nazarov.

The white paper introduces an idea of how better crypto-economic security can be achieved—a concept called  “super-linear staking.” It increases security because, in order to successfully mount an attack on the network, a bad actor would need a budget quadratically greater than the combined security deposits of all oracle nodes. He explained how what’s been tentatively called “the alerting award” works: the value to any one node in an oracle network for proving that somebody is misbehaving has been made very large, he said. So all the nodes have a massive incentive to detect a fault.  “It makes staking scalable enough to support trillions of dollars in value, which is where the system is going.”"

• Eric Wall had harsh words on Chainlink 2.0 (1-5-2021):

"In Chainlink 2.0, the “solution” to the problem that trusted oracles can collude and feed incorrect oracle answers into the blockchain is to have another group of even more trusted oracles be responsible for punishing the first group."

Usage

• From this (23-10-2019) on-chain IntoTheBlock analysis (The author is the CTO at IntoTheBlock):

"IntoTheBlock’s Address analysis shows that over 57% of addresses in the Chainlink network are active. Also the balance between new addresses and addresses with zero balance has been very positive.

An interesting point about this analysis is that it reveals that there are over 11,000 addresses that bought at an average price of $3.54 which could represent the next major level of resistance for a LINK price rally.

After the Coinbase listing the flows of new capital coming into Chainlink has dropped. IntoTheBlock’s Traders analysis reveals that the new money inflows into Chainlink has decreased significatively since June but still remains solid. Despite its global footprint, Chainlink remains more popular within wester investors based on the metrics revealed by IntoTheBlock’s East-West analysis."

• From Our Network #12 (12-3-2020):

"Since the start at the token sale in September 2017, the number of Chainlink-related contracts grew until January 2018 when the overall crypto markets turned over. Growth in contracts stagnated between 400 and 700 contracts for 15 months (increase of only 1.75x) until just before the launch of mainnet in May 2019 when contract growth hit an inflection point and began to turn vertical.

Since then, the number of contracts has increased from 700 to over 5,300 cumulative contracts, a growth of 7.57x in nine months. Recent growth in this metric can largely be attributed to smart contract developers integrating Chainlink oracle functionality in their decentralized applications."

• From this article, which is highly biased towards Chainlink (8-8-2020):

"Supported blockchains on the Chainlink network include Ethereum, Bitcoin, Polkadot, Ava, NEAR, Kava, Tezos, Binance Smart Chain, China’s BSN, IRIS, EVM based chains, Substrate based chains, Harmony, Zilliqa, Ontology, Kadena, Klaytn, CasperLabs, Solana, Hdac, ICON, Conflux, Hedera Hashgraph, Matic, and many more. There are over 60 blockchains which are being integrated into the Chainlink protocol. While initially launched on the Ethereum blockchain, Chainlink’s systems of contracts are being rewritten to run natively on numerous other blockchains with the LINK token being wrapped via a cross-chain bridge. As a result, each Chainlink oracle network will only be subject to the throughput and security assumptions of the particular chain it’s running on."

• From CoinDesk (12-11-2020):

"The monthly subsidies earned by each of the top three Chainlink node operators was close to $100,000 per month between August and October this year. According to research carried out by The Block, between August and October, ChainLayer made over $322,000, LinkPool over $306,000, CertusOne over $293,000 and Fiews over $282,000. September was a particularly good month for them, as the top three nodes all made over $160,000 in said subsidies."

• From Our Network #51 (18-12-2020):

"LINK network’s on-chain volume is mainly (at a 75% rate) caused by 600-1k wallets having a total on-chain volume between 80 to 160M tokens on a weekly basis. The network activity is highly concentrated around a few big players."

Integrations

• Has as on 31-10-2019 more then 70 integrations. Update (17-7-2020): over 200+ integrations in the pipeline, including 60 blockchains.

Most of the following list comes from this Decrypt article (6-3-2019). Others come from this official google docs document. Some come from this unofficial curated list. Some have been added later.

• Accord Project; is building smart legal contracts, hence its interest in Chainlink. Project members include many leading lawyers and enterprise blockchain developers, including IBM and HyperLedger, who want to create an open-source source implementation for oracle data. Announced July 2018
• Aelf; On Sep 10, 2019, Enterprise blockchain giant Aelf announced the integration with Chainlink.
• Amberdata; "They’ve doing been blockchain data for a few years but have recently added Market Data to their repertoire making them the one stop shop for all data involving blockchains. In addition, they’ve just partnered with Chainlink to become an oracle for Market Data." Announced: 23-5-2019
• Akash Network; Will integrate Chainlink (15-10-2020).
• Akropolis; "Akropolis’ model proposes the creation of AFOs (Autonomous Financial Organizations), run like DAOs, that are generated by people who trust each other and would like to leverage their power as a group to conduct financial operations. For the time being, the financial integrations are subject to DeFi protocols and trading. However, according to our long term plan, especially after deploying the Akropolis Chain to allow scaling and interoperability, some of these financial operations will require an interface with traditional financial institutions such as banks, credit issuers, insurers, and others. “We started thinking about integrating oracles, and most specifically Chainlink, around 8 months ago when we revised our projects’ direction and architecture. We have now reached a more stable phase where we launched our MVP into the Ethereum Network and are working towards our own chain on Substrate. After seeing Chainlink’s trailblazing advancements in the oracle space, the choice of Chainlink was natural. We are happy to have the opportunity to work alongside such a great team that is also building towards the Web3 vision,” said Alex Maz, Akropolis’ CTO". Announced: 25-7-2019
• Arbitrum; Chainlink oracles are now live on the Arbitrum Rollup testnet (16-3-2021).
• Axie Infinity; "Is integrating Chainlink’s decentralized price feeds and verifiable randomness tool." (16-11-2020)
• Binance; They will share crypto data to other blockchain platforms. "To allow smart contracts to integrate data from the Binance API, Chainlink has built an external adapter to enable connectivity so that any node operator can provide data. External adapters extend the functionality of a Chainlink node by providing application-specific services from an API to smart contracts. This external adapter is built with serverless architecture in mind, allowing for node operators to run as many external adapters as they like, and only be charged by the cloud provider when that external adapter is used. Binance’s API is available for anyone to connect to their unauthenticated endpoints and the external adapter makes it easy for smart contracts to request and consume the data it provides." Announcement: 25-10-2019. Binance Smart Chain successfully integrated (26-7-2020) Chainlink’s Oracle Solution for Building DeFi.

• Bodhi; A prediction market which launched on the Qtum mainnet in early 2018. It runs on a Proof of Agreement consensus mechanism, which is currently “purely manual.” In the next stage of its evolution, it plans to integrate Chainlink oracles to improve its efficiency. Announced: February 2019
• Brave New Coin (BNC); a data and research company focused on the blockchain and cryptographic assets industry and founded in 2014. Recently BNC has been developing a marketplace for third-party applications, news-feeds, research and market data products unlocked through the BNC utility token. The first application on its platform is aimed at crypto investors and traders, and BNC is working with Chainlink as their data provider to create “individual smart contract oracles” to connect to repayment data. BNC has also teamed up with Nasdaq on the Bitcoin, Ethereum and Ripple Liquid Indexes, which has resulted in speculation that ChainLink will be used to access price data. Announced: September 2018
• BZx; Founded in 2017, U.S.-based BZx developed a protocol on the Ethereum blockchain that powers decentralized margin trading with ultra-fast settlement times for the 60+ tokens supported by on-chain liquidity protocol, KyberNetwork. BZx sees the partnership with Chainlink as a key step in its vision of ushering in a new generation of decentralized exchanges and says that Chainlink opens a wider range of integrations, such as real-time pricing. Announced: November 2018
• Ceek; a developer of virtual- and augmented-reality experiences, founded in 2015 by Mary Spio, a former head of satellite communications at Boeing. ChainLink is listed as the oracle solution for CEEK VR in its whitepaper. ChainLink’s website says it will be used by CEEK to enable on-chain subscriptions via smart contract. Announced: June 2018
• Celer; was founded by four PhDs from MIT, Princeton, UC Berkeley and University of Illinois Urbana-Champaign. Its platform enables fast, easy and secure off-chain transactions and smart contracts. Celer plans to use Chainlink when payment is conditionally dependent on some future condition in the real world being met. Announced: February 2019
• CenterPrime; "CenterPrime, a private Hyperledger based chain with unique access to the Korean open banking API, is sharing foreign exchange rate data from top Korean banks including Hana Bank, Shinhan Bank, Nonghyup Bank, and Industrial Bank of Korea (IBK) to Chainlink’s decentralized oracle network.This integration with Chainlink marks a major breakthrough for the Korean fintech industry. For the first time in history, applications will be able to access decentralized foreign exchange rates compiled by the best banks in Korea. Projects will be able to access high quality Korean bank sourced exchange rates in the local currency KRW. This opens the floodgates for a massive expansion in blockchain-based fintech applications operating cross-border and DeFi applications building homegrown products priced in the local currency KRW." Announcement (26-7-2020).
• Charm; "Chainlink oracles are used to retrieve the underlying price at expiration."
• China’s Blockchain Service Network (BSN) is integrating (23-6-2020) Chainlink’s oracle service into its ecosystem.
• ClinTex; is a blockchain-based, data-management software solution for the clinical trials in the pharma industry. It’s based in the UK and was founded in 2017. It partnered with Chainlink to access data from external pharmaceutical source systems, such as clinical, electronic, case-report forms, to calculate payments that should be made to investigators and vendors. Announced: July 2017
• Crypto.com;  plugged directly into its DeFi wallet, giving users ready access to its price feeds (14-9-2020)
• Dapps Inc; integration. "The integration with Chainlink will enable enterprise users of Salesforce to power their smart contract based B2B workflows by securely accessing off-chain CRM and sales data through DappSuite." Announcement: 17-6-2019
• Data Sports Group; Based in Germany, Data Sports Group collects, normalizes and syndicates sports data from more than 5,000 sporting events worldwide. It will incorporate Chainlink’s oracle services into its API services, which will make it the first service to deliver sports data to smart contracts on-chain, according to its CEO, Sowbhagya Shetty. Announced: March 2019
• DefiDollar; uses (19-7-2020) chainlink oracles for its stability mechanism.
• DocuSign; it's founder Tom Gonser is on the Chainlink board and wants to integrate it in its own business "“I think the DocuSign platform could use oracles if it’s got good data to make decisions. It’s a closed system, at least today, but it could use those oracles to make decisions and make contracts in that system smarter. I think other applications out there could actually rely on those oracles for reliable data. I think it’s beyond just smart contracts in terms of the value of these oracles. I think it’s going to be much bigger than that,” detailed Gosner during a fireside chat with Chainlink CEO Sergey Nazarov."
• DODO; plans on integrating Chainlink (15-10-2020).
• ENS; integration (26-7-2020).
• ETHA; a UK-registered, blockchain-based remittance platform enabling users to use their digital assets to send fiat globally to banks, small local facilities and for mobile top-up. ETHA is working with Chainlink to enable off-chain data feed and API access. Announced: December 2018
• Etherisc; Is using Chainlink for multiple insurance projects (23-11-2020).
• Factom Inc. is U.S-based blockchain innovations company, established in 2014. In 2017, it raised $8 million from investors including Draper Associates and Overstock.com’s Medici Ventures. It provides APIs and managed services to build blockchain applications, systems, and processes. Factom says that it’s collaborating with Chainlink to give Bitcoin and Ethereum smart contract developers easy access to Factom data. Announced: July 2016
• Fantom; Integrates (31-3-2020) Chainlink as its oracle solution and price feed mechanism.
• Filecoin; From CoinDesk (24-3-2021):

"Filecoin has integrated with oracle service Chainlink. The integration will enable connection between Filecoin and Ethereum and other smart contract-enabled blockchains."

• Fuse; from their blog (2-3-2021): "Our Chainlink Proof of Reserve integration will bring secure, reliable, and efficient minting and auditing of Fuse Network’s collateralized stable coin FuseDollar (fUSD), ensuring it is 100% backed by USD Coin (USDC) deposited in a dedicated Ethereum smart contract."
• GameDex; Based in Singapore, Gamedex is a platform for blockchain-powered, collectible cards and games. It’s working with Chainlink to provide sports results to decentralized applications on the Ethereum network. The data collected from Gamedex will be made available via a Chainlink oracle to other decentralized apps. Announced: September 2018
• GET Protocol; integrated (26-7-2020).
• GoChain; "integrate its oracle services capable of bringing real-world data onto the GoChain blockchain" Announcement 12-6-2019
• The Graph; "As part of the integration (10-6-2020), The Graph will index DEX liquidity data that Chainlink oracles can bridge to DEX UIs as reference data for calculating slippage based on a user’s trade size. The Graph will also track gas prices paid per transaction and plans to develop a universal API to allow smart contracts access to any subgraph using a Chainlink decentralized oracle network."
• Harmony; to integrate with Chainlink for Off-Chain Connectivity. Announcement: 5-6-2019
• Haven Protocol; utilizing ChainLink for its private stablecoins (27-4-2021).
• Hedera Hashgraph; they will collaborate to integrate Chainlink’s decentralized oracle network with Hedera’s enterprise-grade distributed public ledger. Announced: 9-5-2019. Still busy with integrating. Chainlink Labs has become a member of the Hedera Council (25-5-2021).
• Hydrogen; Headquartered in New York, Hydrogen builds tools for global financial applications. It plans to utilize Chainlink to enable smart contracts to act on messages sent from its API, allowing users to secure funds inside a smart contract. In a blog post, Hydrogen highlights the importance of native communication, between smart contracts and external systems, as a key factor leading to mainstream usage. Announced: November 2018
• iExec; "collaborate to address the complex off-chain needs of next-generation decentralized applications". Announced: 31-1-2020.
• IOST; "IOST puts significant emphasis on DApp development, as it is the foundation for a healthy and vibrant blockchain ecosystem. At present, there are already 15 Dapps on the IOST mainnet with thousands of active users and growing transaction volumes." Partnered up with Chainlink. Announced: 8-5-2019
• FinNexus; says it has a partnership (1-12-2020).
• FirmaChain; "With Chainlink’s “oracle” network integration, FirmaChain can add-in the DMV’s license database API on duite. Now the only thing the owner of the rental company has to do is sign the rental agreement with the customer and receive his/her driver’s license through duite. which will automatically be cross referenced with the DMV database. If the license were to turn out as fake, duite. will automatically nullify the rental agreement between the driver and the company and take necessary steps following the nullification of the agreement." Announcement (26-7-2020).
• Kaiko; Founded in Paris in 2014, Kaiko is a digital assets data provider covering the top cryptocurrency exchanges. Kaiko collects, normalizes, and distributes cryptocurrency market data and is working with Chainlink to enable a “consistent and secure market data source for smart contracts.” It’s CEO, Ambre Soubiran, said: “We chose to partner with Chainlink because of their proven record of execution in the blockchain ecosystem.” Announced: November 2018
• Kaleido; A platform and marketplace of plug-and-play services and integrations, Kaleido develops software for enterprise blockchain projects. It launched its blockchain platform in November in collaboration with venture venture-production studio, ConsenSys (which also funds Decrypt) and Amazon Web Services. Kaleido will collaborate with Chainlink to provide its clients with smart contract oracles. Announced: November 2018
• KardiaChain; "KardiaChain immediate focus will be using Chainlink to obtain sporting outcomes and statistics for their eSports Incentive Platform." Announcement (26-7-2020).
• Katallassos; a financial services provider. The team includes Reto Trinkler, a Forbes “30 under 30” alumni in the finance industry. The project plans to enable financial contracts on its blockchain to access off-chain data feeds through Chainlink, and its blog post describes the latter as a potential “de facto standard in the blockchain industry.” Announced: January 2019
• Kava; integration. Announced: 26-3-2020.
• Keep3r; Will integrate Chainlink but Keep3rs will also become nodes for Chainlink itself (7-12-2020).
• Kyber integration. Announced: 12-6-2020
• U.S-based MARKET Protocol is targeting derivative trading of trade stocks, cryptocurrencies, and traditional assets, and enables users to create decentralized exchanges and dapps. MARKET Protocol is using ChainLink to help derivatives traders create “highly complex” derivatives’ smart contracts—a “potential gateway to the $100 trillion derivatives market,” according to its blog post. Announced: August 2018
• Matic; integration. Announcement: 12-6-2019
• Gibraltar-registered Mobilum is an instant payment platform and point of sale system that integrates 200 cryptocurrencies and fiat with payment methods ,  including cards and wire transfers.  Using Chainlink’s decentralized oracle network, Mobilum plans to pull market price data to calculate the amount of cryptocurrency needed to settle fiat-denominated conversions. Mobilum’s volatility indexes and best execution rates for major currency pairs will be accessible through Chainlink oracles. Announced: December 2018
• Moonbeam; will integrate it (17-12-2020).
• Morpheus.Network was founded in 2015, is registered in the Seychelles, and  is using blockchain and smart contracts to improve supply-chain inefficiencies and move toward decentralizing global trade . With Chainlink, Morpheus.Network smart contracts will be able to communicate with service providers on both sides of a transaction. Announced: October 2018
• Naka; By the team that developed Bodhi (above), Naka is a blockchain-agonistic platform which enables developers to create blockchain dapps based on utility tokens. It plans to incorporate Chainlink so that the two networks can communicate and to enable “full-fledged dapps.” Announced: February 2019
• NEAR; got Chainlink integrated (31-7-2020).
• Nexo; got Chainlink integrated for price data (8-7-2020).
• Loopring and Chainlink collaborate (28-12-2019) on oracles for Loopring's zkRollup DEX protocol. With their first usecase already implemented; "Loopring v3 drawing on Chainlink oracles to inform protocol-level security parameters"
• LTO Network blockchain; integrated (9-8-2020).
• Oasis Network; got it integrated (29-8-2020).
• Ocean Protocol, based in Singapore, is creating a way to share data while underlying proprietary information remains secure. In April, it launched the beta version of its data-sharing platform—the first to connect people, industries, startups, governments with data and AI experts, and allow them to build data services and marketplaces powered by blockchain technology. Ocean Protocol is the latest startup to integrate Chainlink, which will enable its smart contracts to access off-chain information to trigger certain transactions, such as awarding on-chain contract tokens to people who supply datasets off-chain. Announced: April, 2019
• New York-based Olympus Labs is building a crypto-trading ecosystem, with tools, community, and a decentralized financial products marketplace. It’s working with Chainlink to bring decentralized oracles into financial products for reliable price feeds. The first implementation of Chainlink’s price feed oracles will be in Olympus’s futures products. Announced: November 2018
• OpenLaw is a blockchain-based protocol for creating and executing legal agreements, owned by ConsenSys. It’s targeted at lawyers, enabling them to digitally sign and store legal agreements with security. Recently it partnered with Rocket Layer, an online, consumer-facing startup with tens of thousands of customers. Integration with Chainlink will allow crypto assets transferred on OpenLaw to be denominated in USD and the equivalent amount of Ether calculated at the moment of transfer. For example, if a party agrees to $10,000 per month contract via an OpenLaw agreement, the exchange rate can be converted via ChainLink’s oracle each month to pay in Ether at the latest exchange rates. Announced: August 2018
• Opium Protocol; uses it for its CDSs (7-9-2020).
• Opyn; it's v2 will use Chainlink oracles (29-12-2020).
• Origami Network; “A protocol for building decentralized marketplaces using the Ethereum blockchain“. From their whitepaper: "Origami Review will check the shipment tracking code on the carrier of the order APIs using Chainlink." Announced: in their whitepaper of 26-2-2018
• Plotus; has it integrated (10-8-2020).
• Polkadot; will be the first non-ethereum blockchain to integrate Chainlink. "Chainlink is set to become the first and primary oracle provider for all Substrate-based chains and eventually the entire Polkadot network," Polkadot announced (25-2-2020).
• Polygon; has it enabled (7-3-2021).
• Prosper; from their blog (17-12-2020); "A non-custodial, cross-chain prediction market and hedging platform, has started integrations with Avalanche. The integration is set to be completed in late January 2021. [Will be] using Chainlink oracle price feeds."
• Provable (formerly Oracalize); Under its previous name, Oraclize, Provable has been in use on blockchain mainnets as a “leading oracle service” for smart contracts and blockchain applications since 2015, processing more than a million requests to date, according to its website. However its degree of decentralization has been in question. The company plans to interoperate with decentralized oracle systems, starting with Chainlink. Announced: March 2019
• Reflexer; integrated (26-7-2020).
• Ren; from their blog (5-10-2020): "Ren has collaborated with Chainlink on a new Proof of Reserve mechanism (live on testnet and soon mainnet) to improve the transparency and auditability of its cross-chain assets bridged into the DeFi ecosystem, starting with renBTC, renBCH, and renZEC."
• Reserve; "We plan to use Chainlink to help make the price feeds that the Reserve Protocol relies on more secure and to accelerate our development timeline as we work towards our full mainnet launch." Announcement: 10-6-2019
• Revolution Populari, a decentralized data and identity exchange aiming to take on Facebook and Twitter. Announced (14-7-2020).
• Vancouver-based RTrade Technologies Ltd builds distributed data storage and dapp solutions. It’s partnered with Chainlink to provide oracles for off-chain data storage, and deals with astronomical, weather, financial data and more. Announced: November 2018
• Set Protocol; a bit speculative "To determine condition validity, manager contracts can utilize on-chain data sources such as price feeds (e.g. Maker), blockchain state, oracles (e.g. Chainlink), token curated registries, or even prediction market outcomes (e.g. Augur)." Announcement: 28-2-2019
• Shyft; "Will enable institutions that act as oracles on Chainlink to handle data containing PII (Personally Identifiable Information) in a secure way. Using an attestation model, only specific metadata about the data and sender is shared as required, with strict user consent. For example, knowing that the data belongs to Coinbase would give it a certain certification, and Chainlink’s API users could select which types of data providers they’d like to connect with based on the attestations Shyft offers." Announcement: 28-5-2019 However, as of 12-2019 Chainlink is not mentioned on their website in between all of their partners.
• Skale; mentions Chainlink as an oracle (10-8-2020).
• Sperax; integrated (9-8-2020).
• Solana; says on its website that it is developing an oracle with Chainlink (15-10-2020).
• StaFi; will integrate it (9-10-2020).
• Streamr; has an integration with Chainlink.
• Based in Canada, STK is a cryptocurrency for instant payments at point of sale, via state channels for off-chain transactions. It plans to integrate Chainlink into its smart contract projects, to securely verify payments such as SWIFT banking transactions and to connect to off chain data feeds and external APIs. Announced: December 2018
• SWIFT; started relations with CEO Sergey Nazarov when the name Chainlink was not even in the picture. SmartContract.com (from Sergey) was a winner at a Demo (17-10-2017) and they said they would work together in the future. But as this article (22-1-2018) states:

"The most touted line by ChainLink believers is its partnership with SWIFT, which is no small feat. Very few cryptocurrency projects have the ability to say they have a real partnership with one of the largest financial institutions in the world. Though it’s also likely that Sergey and his team are helping SWIFT develop their own smart contract solution, instead of using ChainLink. We don’t know."

• Swipe; announcement (11-2-2020)
• Synthetix is a decentralized asset platform for on-chain exposure to cryptocurrencies, real-world currencies, commodities, stocks, and indices on the Ethereum blockchain. The Australian startup is working with Chainlink to enable decentralized price feeds across its newly launched trading platform.   Announced: March 2019
• Tezos; integrated. Announcement: 30-4-2020.
• Singapore-based Wanchain enables interoperability between blockchains. It launched 1.0 of its platform in January 2018 and is now on its third iteration. Wanchain has partnered with Chainlink to access data from financial markets, IoT devices and more. In a blog post, Wanchain praised Chainlink’s safety, reliability and ease of use, adding that it will be “an integral component of the new digital, blockchain-based economy.” Announced: November 2018
• Tiny Boxes; "Tiny Boxes — immutable, animated pieces of art stored forever direction on chain — will use Chainlink VRF to determine the features and variations of each NFT-backed Tiny Box, as well as their animation algorithms." Announcement (26-7-2020)
• TrustToken; Chainlink will verify if the stablecoin is backed by actual dollars, on-chain (11-11-2020).
• Value DeFi; integrated it after its own centralized oracle got hacked (19-11-20-20).
• Venus; says it uses Chainlink among other oracles (16-2-2021).
• WBTC; BitGo is using Chainlink to audit Wrapped BTC (1-10-2020).
• The Web 3 Foundation is a Swiss foundation promoting decentralized protocols for Web 3.0. Its primary project is the Polkadot interoperability protocol. Chainlink will make off-chain data feeds, APIs, and traditional payment services available to all contracts on the Polkadot network. “We intend to drive the development of an oracle parachain together with the Chainlink team,” said W3F Executive Director Peter Czaban. Announced: October 2018
• xDai; announced on November 6th, 2020, xDai to integrate Chainlink with help from the Protofire team.
• XYO; "By working together, XYO and Chainlink provide smart contracts secure access to highly valuable IoT data, which can be used to create a multitude of new smart contracts in industries including Insurance and Financial Services." Announced: 20-5-2019
• ZeppelinOS Around 95 percent of Ethereum smart contracts are built on ZeppelinOS libraries. Based in Argentina, the startup makes tools for fast, easy and secure smart contract development on the Ethereum blockchain. It partnered with Chainlink to enable its smart contracts to access data—like the current price of Ether and gas, transaction pool size, and average mining block times on the blockchain. “Outsourcing to a veteran oracle provider means that our team can focus on platform development rather than creating the oracle’s infrastructure,” Zeppelin said in a blog post. Announced: December 2017

Pro's and Con's

Pro's

• The following comes from this analysis (22-1-2018):

"The most touted line by ChainLink believers is its partnership with SWIFT, which is no small feat. Very few cryptocurrency projects have the ability to say they have a real partnership with one of the largest financial institutions in the world. Though it’s also likely that Sergey and his team are helping SWIFT develop their own smart contract solution, instead of using ChainLink."

• When KuCoin got hacked (28-9-2020), many projects showed their centralized powers, however ChainLink did not fork its contracts or froze certain wallets.

Con's

• Had an ICO where SmartContract.com didn't use a smart contract.. Which is a bit weird.
• Surrounding the ICO communication was limited, and a cap dollar amount was chosen instead of crypto. Which created some confusion and irritation in the community. As one blog stated (27-9-2019):

"Many in the Chainlink community complain about lacklustre contact from the company. They actually only published their whitepaper after they had started selling tokens. They recently shut down their Slack channel. They have no roadmap. They are very patchy at releasing progress reports. They have a tiny team, and the CEO is only intermittently active on Reddit. During the ICO debacle, one of their advisors even posted on their subreddit to say that he had no idea what was going on. Compared to other crypto projects, communication from Chainlink is poor."

• Using JSON Schema, which is not the most advanced solution when it comes to schema management.
• Some are claiming their GitHub changes are “are cosmetic changes. The commits are short and not material.” 

• From Crypto Briefing (19-1-2021):

"Vitalik Buterin stated that while he felt the project was a “great solution as one among several,” Chainlink’s “security model is too centralized for me to be satisfied with it being the solution to all oracle problems.”

• Eric Wall had harsh words on Chainlink 2.0 (1-5-2021):

"In Chainlink 2.0, the “solution” to the problem that trusted oracles can collude and feed incorrect oracle answers into the blockchain is to have another group of even more trusted oracles be responsible for punishing the first group."

Competition

• Band Protocol, Aeternity, Coinbase's oracle.
• From this blog (27-9-2019:

"There are 3 main directions that competition will come from:

1. Mobius: Mobius is a middleware DApp platform for Stellar (XLM). It is not specialised in oracle services like Chainlink, but it has oracles in its roadmap so could be a direct competitor.
2. Centralised oracles:  We mentioned earlier that some companies are positioning themselves as trusted centralised oracles. If they can build enough trust they can be strong competitors to Chainlink because they have lower operating costs
3. Competition from platforms themselves: Chainlink want to be free to integrate with any blockchain, but in the future there is always a risk that one or more of the competing blockchain platforms will simply integrate an oracle market feature into their own landscape"

ZAP and Chainlink compared

The following comes from an article that did a 'deep dive into Zap:

"ZAP vs Chainlink: ChainLink is another prominent oracle service in development right now. While both Zap and ChainLink are products in the oracle space, Zap is focused on building a simple-to-use marketplace where smart contracts can connect to oracles through one intuitive interface and ChainLink is focused on building trustful oracle data streams through decentralization.

ChainLink aims to build its own data aggregator service that takes data from a bunch of data streams and returns the majority result. Although this will create highly reliable data streams for the blockchain, there is also tremendous overhead and complexity.

ChainLink data will be more expensive and take longer to deliver, something that is not necessary for highly trusted oracles, such as those from professional or long-standing data providers. ChainLink is excellent for enterprise dApps where data integrity is crucial but not so much for “lower-tier” dApps.

Ultimately, Zap and ChainLink are not necessarily competitors. ChainLink oracles can serve as purchasable oracle services in the Zap marketplace."

iExec and Chainlink

On the difference with Chainlink's doracles, from a iExec slack user:

• "One of the things i find that gives doracles a huge advantage is that its a lot more API provider friendly since providers can sell their api access directly to whitelisted workerpools via the encrypted dataset feature and actually get paid per request with no middleman. But with the other oracle project(link) each node needs a separate API key so in essence each node is just reselling private API data as a middleman. At first i was a fan of the separate api way as it seems more decentralized but after a dev explained how iexec can manage multiple different api keys and keep the keys encrypted via datasets i found the iexec way a lot more neater, "legal", and business friendly."

BCH

• From this Bitcoin.com article (2-12-2019):

"In the areas where Bitcoin Cash could shine — Gambling, games, exchanges, and oracles,” Ruck detailed in his video. “Bitcoin Cash isn’t capable of such smart contracts at the moment so I’ve worked on a few changes to the Bitcoin Cash protocol and I’ve given it a fabulous name — Nimbus.” 

Ruck decided to call his idea Nimbus, because of the intention to “make it rain” with transactions." Ruck broke down some of the smart contract types into genres like gambling, exchanges, and oracles on the ETH chain and insisted that when it comes to “simple smart contracts” BCH could do them “really well.”

Ruck puts an emphasis on the fact that it costs $4 to update the Chainlink oracle. If developers used BCH for this particular oracle example “their revenue would double” Ruck claims."

Team, Funding, Partners

Team

• SmartContract Chainlink is the developer of Chainlink's technology. Located in the Cayman Islands. Their team headquarters is registered at a co-working space (just odd, but whatever).
• LINK is a Smart Contract developed by a team with more than three years of experience building and securing oracles for Bitcoin and Ethereum networks via partnerships with SWIFT to utilize the SWIFT messaging system. 
• Sergey Nazarov; CEO of SmartContract.com
• Steve Ellis; CTO, Previously a software engineer and team lead at Pivotal Labs, where he worked on securing sensitive HIPAA compliant data and building scalable payments automation software. Besides Steve, 2 more team members come from Pivotal Labs.
• Ari Juels; former Technical Advisor, Ari is a professor of computer science in the Jacobs Institute at Cornell Tech and a co-director of IC3 (Initiative for Cryptocurrencies and Contracts). He was previously the chief scientist of RSA. He also contributed to the Chainlink whitepaper. Update (29-8-2020): after acquiring DECO, Juels now works directly from ChainLink.
• Ben Chan; former CTO of BitGo, has joined (16-10-2020) Chainlink to build layer-2 scaling for the network.

Advisors (still as of 12-2019)

• Andrew Miller; Technical Advisor, Andrew is a well known leader in decentralized consensus research and secure blockchain infrastructure. He's an associate professor of computer science at the University of Illinois and an advisor to both Zcash and Tezos.
• Evan Cheng; Technical Advisor, Evan is one of the creators of LLVM which generates the low level machine code running every Apple device, as well as much of Google, Nvidia, and Intel. He is currently Director of Engineering at Facebook.
• Tom Gonser; Advisor and now (22-12-2018) on the board, Tom is the founder of DocuSign, the leading e-signature company that revolutionized digital contracts. He is a seasoned entrepreneur, executive and board member who has created billions of dollars in enterprise value.
• Hudson Jameson; Technical Advisor, Hudson is the Ethereum community manager, a well known authority on smart contracts, and the Ethereum development roadmap. He's written about why he's supporting chainlink. He will continue (3-2-2022).
• Jake Brukhman; Advisor, Jake was previously the CTO at Triton Research, going on to launch CoinFund, one of the leading research groups focused on web 3.0 and blockchain-based infrastructure.
• Brian Lio; Advisor, Brian is the CEO of Smith+Crown, a widely accepted leader in blockchain research. Providing in-depth analysis of both ongoing token sales and the larger evolution of decentralized technology over the past 2 years.

Funding

• Part of the portfolio of 8 Decimal Capital, Consensus Capital ("we’re a partner who supports their growth.") and Nirvana Capital.
• Started a grant program, in which it gave the first grant to its own LinkPool (10-8-2020).
• From Bitcoin.com (31-8-2020):

"An analytics firm, Trustnodes, has reported that Chainlink developers dumped up to $40 million of the Link token once the price peaked."

• Is one of the funders (18-10-2020) of Gitcoin Grant round 7 (and possibly continues to do so).

Partnerships

• Developing an oracle on Polkadot
• Google announced (14-6-2019) an integration with Chainlink to develop middleware in order to connect Ethereum to its enterprise cloud data warehouse. Through a Chainlink oracle, a smart contract can fetch data from an on-chain query to a data warehouse like Google’s BigQuery.
• Working with SWIFT on their own SWIFT Smart Oracle. Allowing smart contracts on various networks to make payments, send governance instructions, and release collateral with over 11,000 banks.
• Will be collaborating with Oracle. "Chainlink is a partner (31-10-2019) of Oracle’s startup program. This partnership will help Chainlink to generate additional revenue streams by selling its data. One more advantage of being the member of the Oracle for Startups program is to receive oracle cloud credits, pricing discounts and access to the Oracle marketing services." Regarding the partnership, Fernando Ribeiro, a senior manager with Oracle claimed (31-10-2019):

“We are going to co-develop Chainlinks with 50 qualified startups to prepare them to sell their data to Oracle’s 430,000 customers in 175 countries on the Oracle Blockchain Platform. The startups are going to be announced in Oracle Code One in September.”

Update (28-10-2019) Fist 20 startups have been announced: "The ecosystem of API providers (startups) will work in concert with Chainlink node operators and smart contract developers, creating a network of mutually interested entities. Neutral third-party API marketplace providers like LinkPool and Honeycomb will act as the catalyst by providing services that will cultivate interest and build “chainlinks” between API providers (startups), independent Chainlink node operators, and smart contract developers."

• Partners (as of 12-2019 still on the website) with Cornell’s IC3 to launch the first Intel SGX secured link between smart contracts and secure external data. This later led to the below acquirement.
• "We've been chosen as a 2017 Blockchain Applications Cool Vendor by Gartner." (as of 12-2019 still on the website)
• In November 2018, Chainlink acquired Town Crier, a “trusted hardware system,” which ensures data privacy and security for smart contracts. Town Crier was developed by Ari Juels, a computer science professor at Cornell University, who also contributed to Chainlink’s whitepaper. Town Crier is described as a “high-trust bridge” between the Ethereum blockchain and online data sources. It’s patent-pending system contains a program that runs inside an isolated piece of hardware called a “secure enclave.” Its function is to protect the program from malicious attacks and keep the computation confidential when it answers data queries from smart contracts; it does this after retrieving answers from external websites.

As this article described (10-2019):

"The operators of Town Crier’s server cannot even tamper with the data processed by the system. For Chainlink, Town Crier bolsters the privacy and verifiable authenticity of data that flows into its decentralized Oracle network. Oracle nodes on Chainlink that use Town Crier will be able to provide guarantees that the data they are providing has not been tampered with before or during its relay to the smart contract. Town Crier will first be implemented with Ethereum but can provide authentic data into any ecosystem."

• Has a partnership with MARKET Protocol (still as of 8-2019)

• From Proof of Work #77 (23-10-2019):

"Announced a new platform, FOAM In-Sight in collaboration with Google Cloud Platform, Blocklytics and FOAM for a hybrid cloud/blockchain application with a demo for DevConV. Main-net next."

• Partners (22-12-2018) with Request Network and Signal Capital.
• At the mainnet launch alleged "white label" partners such as Salesforce and Microsoft Azure names were also 'flying around'.
• Figment is a Chainlink Oracle. From their website (9-3-2020): "Figment Networks has been successfully running a Chainlink oracle and data processor node since 9/19. Chainlink is not yet decentralized. Therefore, staking or node operation services are not yet available for LINK token holders."
• Is a part of a larger team that is participating (4-3-2020) in building Baseline Protocol (announced by ConsenSys and EY).
• Celsius plans (31-3-2020) to use Chainlink’s price feeds, while Chainlink will use Celsius’ treasury management solution for its BTC and ETH cryptocurrencies.
• One of the sponsors (3-10-2019) of Hyperledger Avalon.
• One of the four sponsors of Week in Ethereum (1-5-2020).
• Chainlink partners (5-8-2020) with War Riders to create a hybrid solution for human readable Ethereum names that removes friction for blockchain gamers.
• On the website of Opium Protocol it is mentioned as one of its partners (7-3-2021).
• Will be on the Hedera Hashgraph Council (25-5-2021).
• Is part of the DeFi for the People innitiative by Celo (31-8-2021).
• Is mentioned as a partner to Octopus Network on their website (14-3-2022).

(:

Knowledge empowers all and will help us get closer to the decentralized world we all want to live in!

Making these free wiki pages is fun but takes a lot of effort and time.

If you have enjoyed reading, tips are appreciated :) This will help us to keep expanding this archive of information.

ETH tip address: 0x83460bE5F218b1520B69D702cE60A1DE37dD8E31