An oracle module for substrate, used together with srml_collective.
- substrate version:
polkadot-master - demo page: https://oracle.debank.com/
- ws:
wss://test-api.debank.io:2053/oracle/
Under testing...
- Oracle management and business logics should be decoupled.
- Should follow conventions of
substrateitself.
- Staking/Rewarding/Slashing
- One should stake a specific amount before becoming an oracle.
- Oracle will receive rewards if it successfully witnessed an offline event.
- Oracle will be slashed if it missed a reporting window.
- Oracle can be slashed by major parties if its malicious activity is agreed upon. (parties such as council)
- Oracle Election: oracles will be elected by staking amount every specific duration.
- Reporting Cycle: an oracle should report an event in a specific duration. If so, it'll be paid, if not, it'll be slashed.
- Unlock Duration: an oracle's staked coin will not be unlocked until a future time.
Currency: Currency type.OracleFee: The amount of fee that should be paid to each oracle during each reporting cycle.MissReportSlash: The amount that'll be slashed if one oracle missed its reporting window.MinStaking: The minimum amount to stake for an oracle candidate.MaliciousSlashOrigin: The origin that's responsible for slashing malicious oracles.Count: The maxium count of working oracles.ReportInteval: The duration in which oracles should report and be paid.ElectionEra: The duration between oracle elections.LockedDuration: The locked time of staked amount.ChangeMembers: The actual oracle membership management type. (Usually thesrml_collective::Trait)
bid(amount: Balance): bind amount to list as oraclce candidates.slash_by_vote(who: AcocuntId, amount: Balnace): slash oracle by third parties.unbind(amount: Balance): unbind amount.
Oracle module has implemented the following trait. Business module should use this trait to communicate with oracle module.
pub trait OracleMixedIn<T: system::Trait> {
/// tell oracle module that an event is reported by a speicifc oracle.
fn on_witnessed(who: &T::AccountId);
/// predicate if one oracle is valid.
fn is_valid(who: &T::AccountId) -> bool;
}Oracles: acting oracles.OracleLedger: staking ledger of oracle/candidates.WitnessReport: blockstamp of each oracle's last event report.OracleCandidates: oracle candidates.CurrentEra: Current election era.OracleLastRewarded: oracle reward records.
OracleBonded(AccountId, Balance): Amount bonded by one oracle.OracleUnbonded(AccountId, Balance): Amount unbonded by one oracle.OracleSlashed(AccountId, Balance): Amount slashed to one oracle.OraclePaid(AccountId, Balance): Amount paid to one oracle.CandidatesAdded(AccountId): Candidate added.CandidatesRemoved(AccountId): Candidate remove.OracleStakeReleased(AccountId, Balance): Amount unlocked for one oracle.
Current repo has an example of coin price oracle (link), build use:
$ cargo buildAnd reporters are listed in scripts/reporters/:
$ cd scripts/
$ npm install
$ node reporters/binance.js ...