PolkaOracle

Chainlink hasn't deployed here. We did.

The Problem

Polkadot Hub has no price oracle. Chainlink, Pyth, DIA, Band -none of them have deployed to Hub's PVM. Every DeFi primitive -lending, stablecoins, derivatives, liquidation engines -requires reliable on-chain price data to function. Without an oracle, no DeFi can exist on Hub.

Parachains face the same gap. There's no native way to get a trusted price feed from Hub and distribute it across the ecosystem. Projects either build their own fragile price feeds or don't build at all.

The Solution

PolkaOracle is the first decentralized price oracle built natively for Polkadot Hub. Independent reporters stake PAS tokens, fetch prices from multiple exchanges (CoinGecko, CoinPaprika, Binance), and submit them on-chain. The contract aggregates via median -computed by a Rust contract compiled to PolkaVM (RISC-V) -and distributes prices cross-chain to any parachain via XCM.

Reporters who deviate from the median get slashed. No trust required -just math and stake.

Links

Live App	polkaoracle.vercel.app
Dashboard	polkaoracle.vercel.app/dashboard
Docs	polkaoracle.vercel.app/docs
Repo	github.com/IronicDeGawd/polkaoracle-dorahacks-2026

Deployed Contracts

Polkadot Hub TestNet · Chain ID 420420417 · Explorer

Contract	Address
PriceOracle	0xaf781298fE769738eF529816c11C121Ea8887Fc9
OracleStaking	0xd2A807a574CAEa31e6DA7102feA1b2071A6a3321
OracleConsumer	0xa442FAdAa070fB1C89d0dBFBfa0B488110E25146
RustMedian	0x454d0fB0BBB30c08f05e2DfEF94E0fe106eDFADA

Moonbase Alpha · Chain ID 1287 · Explorer

Contract	Address
XcmPriceReceiver	0xad81ed5a1e0c8Ea28E8a52Fee6aC1D51131DD0cB

Feeds: DOT/USD, BTC/USD, ETH/USD (8 decimal precision)

Architecture

  CoinGecko ──► Reporter 1 ─┐                          ┌─ RustMedian (RISC-V)
CoinPaprika ──► Reporter 2 ─┤──► submitPrice() ──► PriceOracle ──┤  (staticcall + fallback)
    Binance ──► Reporter 3 ─┘         │                └─ Solidity median
                              OracleStaking           ──► Relay ──► Moonbase Alpha
                         (10 PAS min stake, 50% slash)

• PriceOracle -Submission rounds, median aggregation, TWAP (60-entry circular buffer), deviation checks, XCM broadcast
• OracleStaking -Stake/unstake with cooldown, slashing, pause, reentrancy guard
• OracleConsumer -Reference dApp: getDOTPrice, calculateDOTValue, collateral checks
• XcmPriceReceiver -Cross-chain receiver with batch relay and staleness validation

Why Only Polkadot

PolkaOracle isn't a Chainlink fork redeployed on a new chain. Its design depends on primitives that only exist in Polkadot's architecture:

• No competing oracle on Hub -Chainlink, Pyth, DIA, and Band have not deployed to Polkadot Hub. PolkaOracle is the first and only oracle available to PVM smart contracts.
• XCM-native price distribution -Prices broadcast to any parachain via the XCM precompile (0x0...0a0000). No bridge contracts, no third-party relay protocols -this is a Polkadot-only messaging primitive.
• Native token staking for accountability -Reporters stake PAS (Hub's native token) directly. Slashing is enforced on-chain without deploying a separate staking token. On EVM L1s, this requires a custom ERC-20 + staking contract.
• PVM execution -Compiled to PolkaVM (RISC-V), not the EVM. Same Solidity source, different runtime with Polkadot-native 3-dimensional gas metering (ref_time + proof_size + storage_deposit).

Rust on PVM

PolkaOracle's median aggregation is also implemented as a native Rust contract compiled to PolkaVM (RISC-V). The Solidity oracle calls the Rust contract via standard ABI -demonstrating cross-language smart contract interop on PVM.

PriceOracle.sol (Solidity) ──► IRustMedian.median() ──► RustMedian (Rust/RISC-V)

Implementation	median(3 values) Gas	Binary Size	Notes
Solidity	~2,400 (est.)	-	Insertion sort + median, EVM-compiled to PVM
Rust	1,829	15 KB	Native RISC-V, same ABI, #![no_std]

The Rust contract is compiled with cargo build --release using pallet-revive-uapi for host functions and alloy's sol! macro for ABI compatibility. Source: rust-median/.

Deployed: 0x454d0fB0BBB30c08f05e2DfEF94E0fe106eDFADA on Paseo Hub TestNet

Usage

PriceOracle oracle = PriceOracle(ORACLE_ADDRESS);
bytes32 DOT_USD = keccak256(abi.encodePacked("DOT/USD"));

// Spot price
(uint256 price, uint256 timestamp) = oracle.getPrice(DOT_USD);

// Fresh price (reverts if stale)
(uint256 fresh, ) = oracle.getFreshPrice(DOT_USD, 1 hours);

// TWAP (manipulation resistant)
uint256 twap = oracle.getTWAP(DOT_USD, 5 minutes);

// XCM broadcast to parachain
oracle.broadcastPrice(DOT_USD, 2000);

Real-world example -a lending protocol using PolkaOracle for collateral valuation:

contract LendingPool {
    PriceOracle oracle = PriceOracle(0xaf781298fE769738eF529816c11C121Ea8887Fc9);
    bytes32 constant DOT_USD = keccak256(abi.encodePacked("DOT/USD"));

    function borrow(uint256 dotCollateral, uint256 borrowUSD) external {
        uint256 dotPrice = oracle.getTWAP(DOT_USD, 5 minutes); // manipulation-resistant
        uint256 collateralUSD = (dotCollateral * dotPrice) / 1e8;
        require(collateralUSD >= borrowUSD * 150 / 100, "Under-collateralized");
        // ... execute borrow
    }
}

See OracleConsumer.sol for a full reference implementation, or the integration docs for JavaScript examples.

Quick Start

git clone https://github.com/IronicDeGawd/polkaoracle-dorahacks-2026.git
cd polkadot-hackathon

# Contracts
cd contracts && npm install
npx hardhat test          # 91 tests

# Reporter Bot
cd ../reporter && npm install
npm run reporter:1        # CoinGecko
npm run reporter:2        # CoinPaprika
npm run reporter:3        # Binance

# Frontend
cd ../frontend && npm install && npm run dev

Tests

91 tests across 3 suites covering price submission, median aggregation, TWAP calculation, deviation rejection, stale data handling, slashing, round management, XCM relay, and Rust median integration (fallback, CEI ordering, multi-feed).

cd contracts && npx hardhat test    # 91 passing

Security

• Reentrancy guard on all staking operations
• 10% deviation cap (5x wider band for stale prices to prevent freeze)
• Configurable max price age (1 hour default)
• Time-bounded submission rounds with monotonic round counter
• 50% slashing for reporters deviating from median
• SCALE-encoded XCM with conservative weight estimates

Gas Benchmarks (Paseo Hub Testnet)

Operation	Gas (ref_time)	Notes
submitPrice()	66,586	Write: stores price, triggers median aggregation
getPrice()	1,316	Read: single storage lookup
getTWAP()	~2,390	Read: iterates circular buffer (estimate)

Rust vs Solidity Median (pure compute)

Implementation	Gas (ref_time)	Binary	Notes
Rust (RISC-V)	1,829	15 KB	PolkaVM-native, called via staticcall
Solidity	~2,400	-	Inline in PriceOracle, used as fallback

PriceOracle tries the Rust contract first; if the staticcall fails or returns unexpected data, it falls back to the Solidity implementation automatically.

PVM uses 3-dimensional gas: ref_time (compute), proof_size (state proof), and storage_deposit (new storage). The numbers above reflect ref_time only. Measured on live testnet with benchmark script.

Tech Stack

Solidity ^0.8.28 · Rust (PVM-native RISC-V) · PVM (PolkaVM) · Hardhat · ethers.js v6 · Next.js · Recharts · XCM V3

License

MIT