UMA optimistic oracle
Optimistic oracle that verifies any statement with bonds, a challenge period and token-holder votes.
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UMA key facts
| Category | Blockchain oracle |
|---|---|
| Chains | Ethereum and EVM networks |
| Platforms | Web |
| Token | UMA |
| Open source | Yes, AGPL-3.0 on GitHub (UMAprotocol/protocol) |
What is UMA?
UMA runs the Optimistic Oracle, which verifies statements rather than streaming prices. A claim is posted with a bond, stands if no one disputes it during a challenge period, and goes to a UMA token-holder vote if disputed. Polymarket and Across use it, per UMA's homepage.
UMA pros and cons
- Handles arbitrary questions, not only prices
- Used by Polymarket and Across
- Code public on GitHub under AGPL-3.0
- Answers arrive only after the challenge period, so it does not fit live price feeds
- Disputed outcomes depend on UMA token-holder votes
UMA FAQ
What is UMA?
UMA runs the Optimistic Oracle, which verifies statements rather than streaming prices. A claim is posted with a bond, stands if no one disputes it during a challenge period, and goes to a UMA token-holder vote if disputed. Polymarket and Across use it, per UMA's homepage.
Which chains does UMA support?
Ethereum and EVM networks.
Sources
How this page works
Sources: UMA: official site, UMA: Home, UMA: GitHub repository. Data as of Sep 26, 2026.
Not affiliated with any project listed. Educational content, not financial advice.