Abstract

Endorphin is a non-custodial DeFi wellness dapp where users stake USDC into time-boxed fitness competitions. On join, the pool converts USDC to PT-USDe on Pendle to lock a fixed APR; users receive non-transferable sMOL (Staked molecules” as receipts of their pro-rata position. A Flare-backed oracle posts Strava activity normalized to “Effort Points”. at the end; participants who meet the goal claim the entire PT-USDe pot pro-rata (optionally auto-swapped to USDC), while non-finishers are slashed. The factory→pool architecture keeps rules transparent, payouts deterministic.

1) Motivation & Goals

Fitness challenges fade without stakes. Endorphin aligns incentives by putting real value on consistency: finishers gain, quitters forfeit. The goal for v0 is an auditable, demo-ready pipeline with minimal trust and simple economics

2) System Overview

• On-chain
  • EscrowFactory: deploys competitions and sets the oracle signer.
  • EscrowPool (per competition): accepts USDC, buys PT-USDe, mints sMOL, tracks EP, settles, and pays winners.
• Off-chain
  • Oracle Aggregator (Flare): fetches Strava data, computes Effort Points (EP), signs EIP-712 progress messages.

3) Tokens & Assets

• USDC: user stake (input asset).
• PT-USDe: Pendle Principal Token at maturity T; fixes APR (1 PT → 1 USDe at T).
• sMOL: per-pool, non-transferable receipt token representing a user’s fraction of the pool’s PT-USDe.

Constraint: choose T ≥ liveEnd + buffer, so the PT maturity never precedes settlement.

4) Core Mechanics (Flow)

4.1 Join

1. User calls join(usdcAmount).
2. Pool pulls USDC, swaps USDC → buys PT-USDe (slippage-limited).