Concepts
The ocr
module is to store chainlink's OCR information into on-chain by verified members.
Off-chain reporting consists of N nodes (oracles), gathering data from external sources. Reports are being exchanged in a p2p fashion between oracles to get signatures of approval. A subset of nodes (transmitters) is identified by the ocr
module on-chain, they must submit the reports to module, the first transmitter who hits the chain gets an extra reward to cover gas costs. Other transmitters are not. All oracles participating in the round are getting paid. ocr
module stores median value from the reports.
OCR Terminology
The protocol periodically sends oracle reports to the OCR module. The reporting protocol is comprised of three components: pacemaker, report generation and transmission.
Pacemaker
The pacemaker drives the report generation process which is structured in epochs. Each epoch has a designatd leader who the pacemaker then tasks with starting the report generation protocol. If the leader does not produce a valid report in time, the pacemaker also aborts the current report generation and starts a new epoch.
Report Generation
For a given epoch, the report generation protocol enters into rounds where observations are gathered and (given conditions are met such as heartbeat and deviation) a signed oracle report is generated. The rounds are controlled by a leader node who controls the frequency of rounds, gathers the observations and generates the report.
Transmission
The transmission protocol then transmits the generated report to the OCR module.
Off-chain OCR integration
Provide means to communicate with Injective using sdk-go
Read data from the module, such as a list of approved oracles
Submit reports as Msgs (Implement
ContractTransmitter
)Implement
OffchainConfigDigester
Implement
OnchainKeyring
for producing signatures that will work on the target chain moduleImplement
ContractConfigTracker
for tracking changes of the chain module config (gov approved)
Notes:
Reports are timestamped in Epoch-Round fashion
ocr
module verifies the signatures of oracles on the reportocr
module records oracles who contributed to a report, for the payoutocr
module stores the median of the observationsocr
module provides extra reward for the first submitter of a Msg
Integration Overview
Chainlink has several price data feeds including:
80 Crypto/USD pairs (e.g. ETH/USD, BTC/USD)
17 Stablecoin pairs (e.g. USDT/USD, USDC/USD)
73 ETH pairs (e.g. LINK/ETH)
17 Forex pairs (e.g. GBP/USD, CNY/USD)
A derivative market on Injective specifies the following oracle parameters:
An oracleBase (e.g. BTC)
An oracleQuote (e.g. USDT)
An oracleType (e.g. Chainlink)
Thus for a BTC/USDT derivative market on Injective, the oracleBase would be BTC/USD, the oracleQuote would be USDT/USD and the oracleType would be Chainlink. The price for the market would then be obtained by dividing the BTC/USD price with the USDT/USD price, leaving the BTC/USDT price.
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