Quiz Entry - updated: 2026.07.30
Name a few real oracle tools and which pattern each realizes.
Orisi (Bitcoin, multi-oracle voting) is pull-based inbound; Oraclize/Provable and Chainlink serve inbound feeds; Witnet is a decentralized oracle network — most real tools are inbound.
| Tool | Character |
|---|---|
| Orisi | Distributed set of independent oracles for Bitcoin; a majority must agree, and funds sit in a multi-signature address requiring their signatures — a pull-based inbound design |
| Oraclize / Provable Things | Popular inbound-oracle service across many contract platforms; acts as a trusted intermediary to varied data sources, and can behave as both push- and pull-based |
| Chainlink | General-purpose framework for decentralized inbound oracles, decentralizing at both the oracle and the data-source level via multiple external adapters |
| Witnet | A decentralized oracle network protocol where nodes earn tokens for honest reporting, with an Ethereum bridge |
The through-line: the overwhelming majority of deployed tools are inbound — bringing outside data in. Outbound/reverse oracles remain comparatively rare, which is part of why formalizing all four patterns is valuable.
Go deeper:
Chainlink (Wikipedia) — the most widely deployed decentralized inbound-oracle framework.- Witnet: A Decentralized Oracle Network Protocol (arXiv) — the token-incentivised oracle network with an Ethereum bridge.
- Orisi white paper — the Bitcoin multi-oracle, majority-vote, multisig design named on this card.