Sapience is a decentralized forecasting community which aims to create the most accurate prediction markets on the planet. It leverages the Foil protocol to create prediction markets using Uniswap and UMA.

Sapience and its dependencies are completely open source. The API is free to use with rate limiting. Paid keys will be made available in the future.

The Foil protocol is immutable. Once a market has been deployed onchain, no one can modify its logic. Anyone can permissionlessly interact with the markets onchain, regardless of API usage.

The API is in alpha and subject to change without notice.

Overview

Each market group lives at a unique smart contract address on a blockchain. They consist of one or many markets, each with a sequential Market ID and a question. Markets can resolve to a numeric value (e.g. the average temperature in New York City in January of 2026) or binary value (with 1 representing "yes", 0 for "no".)

Market groups may consist of just one market, multiple binary markets with the same ending time (for multiple-choice questions), or a series (e.g. for average temperature in January, February, etc.)

Every market accepts collateral and allows base and quote tokens to be traded in a Uniswap pool (which is effectively an onchain orderbook) prior to an end time. Once the market is settled via UMA, individual positions can be settled.

For a binary (yes/no) market, the base tokens represent a prediction that the market will resolve to "yes". If the market resolves to "yes", everyone holding a base token can redeem a pro-rata share of the collateral. Otherwise, those holding a quote token redeems pro-rata.