What is an Oracle?
Polymarket resolves its markets by using oracles.
What is an oracle?
An oracle is a trusted source that provides the official outcome of events or real-world data such as prices and reported numbers.
Why does Polymarket use oracles?
Polymarket does not have a way of knowing real-world outcomes on its own. Oracles provide Polymarket with real-world outcomes so it knows how a market should resolve.
Which oracles does Polymarket use?
Polymarket uses three oracles: the Markets Team, Chainlink, and UMA Protocol.
Markets Team
Polymarket has a Markets Team whose job is to create markets, write rulesets, and resolve markets.
On Polymarket US, the Markets Team is responsible for resolving markets by checking whether the resolution criteria have been satisfied. On Polymarket International, the Markets Team provides clarifications about how a market should resolve.
Chainlink
Chainlink is the largest decentralized oracle network. It delivers secure, tamper-resistant data from outside sources into blockchain applications.
How does Chainlink work?
Chainlink collects information, such as asset prices, from multiple independent providers. It then aggregates and delivers that data onchain in a way that is timestamped and verifiable, reducing the risk of errors or manipulation.
How does Polymarket use Chainlink?
Polymarket uses Chainlink to resolve markets that depend on real-time numbers like crypto prices. With the integration of Chainlink Data Streams (low-latency, verifiable price feeds) and Chainlink Automation (timely, automated onchain settlement), Polymarket can run fast-resolving markets such as 15-minute crypto price markets.
UMA Protocol
UMA (Universal Market Access) is an optimistic oracle designed for questions where outcomes are harder to verify or do not have a single data source.
How does UMA work?
UMA uses a three-step process to verify real-world outcomes and bring that data onto the blockchain:
Proposers submit an answer to the market question.
Disputers can challenge the answer if they believe it is wrong.
Voters make the final decision if a dispute occurs.
This system creates checks and balances so that incorrect answers can be caught and corrected.
How does Polymarket use UMA?
Polymarket uses UMA for markets that cannot be resolved through automated data feeds like Chainlink. These are often subjective questions or situations where there is no single official source. By using UMA, Polymarket ensures that these markets still resolve in a transparent way, with the community involved in verifying the outcome.