Chainlink Oracle Network
Chainlink is the dominant oracle provider in DeFi, securing $75B+ in TVL. It aggregates price data from multiple independent node operators, each pulling from multiple data sources. A new aggregation round triggers when the off-chain price deviates beyond a threshold — or when a heartbeat timer expires. The median of all node responses becomes the on-chain price. This architecture makes it extremely expensive to manipulate a single price feed.
⚙️ Aggregation Round Simulator
Configure the oracle network and watch how individual node reports converge into a final aggregated price. Each node samples from slightly different sources, introducing variance.
Aggregated Price
$2,000.00
Node Spread
±$5.20
Rounds Triggered
3
Update Latency
~12s
🔗 How Aggregation Works
📡
Data Sources
CEXs, DEXs, OTC desks provide raw price data
→
🖥️
Node Operators
Independent operators aggregate & submit answers
→
📊
Aggregator
On-chain contract takes median of all responses
→
✅
Price Feed
DeFi protocols read the latest answer on-chain
🛡️ Security Properties
BYZANTINE FAULT TOLERANCE
Using median aggregation, up to ⅓ of nodes can report malicious data without affecting the final price. With 21 nodes, an attacker must compromise 11.
DEVIATION THRESHOLD
New rounds only trigger when price moves beyond the threshold (e.g., 1%). Saves gas during stable markets while ensuring timely updates during volatility.
HEARTBEAT GUARANTEE
Even if price doesn't move, a heartbeat forces an update (e.g., every 1 hour for ETH/USD). DeFi protocols can reject stale data based on this timestamp.
⚡ Key Price Feeds
ETH / USD21 nodes · 0.5% deviation · 1hr heartbeat
Used by Aave, Compound, MakerDAO
BTC / USD31 nodes · 0.5% deviation · 1hr heartbeat
Highest-security feed on Chainlink
USDC / USD21 nodes · 0.1% deviation · 24hr heartbeat
Stablecoins use tighter thresholds