Key Concepts Glossary

Payment Engine

The core system that receives a payment instruction, computes the best route, simulates it, executes it, and delivers. Everything else in Papillae serves this.

Stablecoin

A cryptocurrency whose value is pegged to a fiat currency. USDC is pegged 1:1 to the US dollar. Papillae uses stablecoins as the settlement rail because they move on-chain in seconds and do not fluctuate in value during transit.

Smart Contract

A program that lives on a blockchain and executes automatically when conditions are met. Papillae's smart contracts handle fund routing, execution, and delivery without Papillae staff needing to manually process anything. The code is the operator.

Route

The specific path a payment takes from source to destination. Could be a single hop - USDC on Ethereum directly to a recipient on Ethereum. Could be multiple hops - ETH swapped to USDC on Ethereum, bridged to Polygon, delivered as USDC to a recipient there. The engine computes this automatically.

Bridge

A protocol that moves assets between two different blockchains. Papillae uses Circle CCTP as the primary bridge for USDC, with Across Protocol, Stargate, and Wormhole as fallbacks depending on the corridor.

Swap

Exchanging one token for another on the same blockchain. If a user sends ETH and the recipient needs USDC, a swap happens before bridging. Papillae uses 1inch on Ethereum and Polygon, and Jupiter on Solana - these are aggregators that find the best rate across all available liquidity.

Off-Ramp Partner

A licensed financial institution that receives stablecoin on-chain and pays out local fiat currency to a recipient's bank account or mobile wallet. Yellow Card handles Africa, Coins.ph handles the Philippines, Bitso handles Latin America. They are regulated entities that carry the licensing obligation for fiat delivery.

Corridor

A specific source-to-destination payment path. US to Nigeria is a corridor. US to Philippines is a corridor. Each corridor has its own liquidity characteristics, partner coverage, average fees, and typical settlement times. Papillae tracks performance per corridor.

Pre-Flight Simulation

Before any real funds move, the payment engine runs the entire route as a dry run. It checks liquidity depth, estimates slippage, verifies compliance, and confirms the off-ramp partner is accepting transfers. If simulation fails, nothing moves and the engine explains why.

Session Key

A limited signing authority that a user grants to Papillae's system for autonomous execution within defined boundaries. The boundaries - max per transaction, max per day, whitelisted recipients - are enforced by the smart contract in code. Revoking a session key instantly removes autonomous access.

Proof Bundle

A structured record generated for every transfer containing the compliance checks that ran, which passed, which providers were used, the risk scores at the time, and a signed hash for tamper detection. This is your audit trail.

Telemetry

Performance data recorded for every transfer - actual vs estimated fee, actual vs estimated time, which protocols succeeded or failed, slippage accuracy. This data trains the routing engine to make better decisions on the same corridor over time.

Intent

A natural language payment instruction. "Send $200 to Ahmed in Nigeria" is an intent. The intent parser extracts the structured data from it - amount, recipient, corridor, urgency - and converts it into a RouteData object the engine can execute.