Pyth is an oracle that publishes financial market data to multiple blockchains. Pyth uses an on-demand price update model that is slightly different from other oracles you may be more familiar with. Pyth price updates are streamed off-chain via the Wormhole Network, a cross-chain messaging protocol. These updates are signed such that the Pyth on-chain program can verify their authenticity. Updating the on-chain price is a permissionless operation: anyone can submit a valid Wormhole message to the Pyth contract to update the price.