Price Oracle
価格オラクルは、外部の市場データをスマートコントラクトに提供し、現実世界の価格変動に対応できるようにします。
価格オラクルは、分散型金融（DeFi）アプリケーションの不可欠なコンポーネントです。これらは、オンチェーンのスマートコントラクトと、集中型取引所（CEX）や分散型取引所（DEX）などのオフチェーンのデータソースとの間のギャップを埋めます。これにより、スマートコントラクトは、さまざまな資産のリアルタイムの価格フィードにアクセスし、市場の状況に基づいてアクションをトリガーできます。オラクルがないと、スマートコントラクトは孤立し、外部データと対話できなくなり、その機能が大幅に制限されます。オラクルは、金利や気象データなどの他のデータも提供できますが、価格フィードはDeFiで最も一般的なユースケースです。
graph LR
Center["Price Oracle"]:::main
Pre_economics["economics"]:::pre --> Center
click Pre_economics "/terms/economics"
Rel_oracles["oracles"]:::related -.-> Center
click Rel_oracles "/terms/oracles"
Rel_smart_contracts["smart-contracts"]:::related -.-> Center
click Rel_smart_contracts "/terms/smart-contracts"
Rel_chainlink["chainlink"]:::related -.-> Center
click Rel_chainlink "/terms/chainlink"
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classDef pre fill:#0f172a,stroke:#3b82f6,color:#94a3b8,rx:5,ry:5;
classDef child fill:#0f172a,stroke:#10b981,color:#94a3b8,rx:5,ry:5;
classDef related fill:#0f172a,stroke:#8b5cf6,stroke-dasharray: 5 5,color:#94a3b8,rx:5,ry:5;
linkStyle default stroke:#4b5563,stroke-width:2px;
🧠 理解度チェック
🧒 5歳でもわかるように説明
Imagine a [smart contract](/ja/terms/smart-contract) is like a robot that can only follow instructions inside its factory. A price [oracle](/ja/terms/oracle) is like a trusted messenger who goes outside, checks the price of something, and tells the robot the correct price so it can do its job.
🤓 Expert Deep Dive
Price oracles are essential for enabling complex smart contract functionalities such as derivatives trading, lending protocols, stablecoins, and synthetic assets. The security and reliability of a price oracle directly impact the security of the dependent DeFi protocols. Architecturally, DONs often use a Time-Weighted Average Price (TWAP) or Volume-Weighted Average Price (VWAP) calculation across multiple sources to mitigate the impact of single-source manipulation or temporary exchange volatility. Cryptoeconomic incentives, such as staking and slashing mechanisms for oracle node operators, are employed to ensure honest data reporting. Edge cases include handling exchange downtime, API rate limits, and the 'oracle problem' itself – the inherent difficulty in obtaining truly decentralized and manipulation-resistant external data. Advanced oracle designs incorporate threshold signatures, verifiable random functions (VRFs), and cross-chain data feeds to enhance security and utility.