> ## Documentation Index
> Fetch the complete documentation index at: https://corridor.udokaam.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# ADR 0001: pathUSD as the settlement unit

> Corridor holds balances in pathUSD on Tempo and accepts any USD TIP-20 at the edges, with a per-corridor policy to settle in USDC.e when depth requires.

## Context

Every stablecoin on Tempo is a TIP-20, including USDC.e (Stargate-bridged USDC). "USDC or a native token" is a false choice; the real question is which TIP-20 is the unit of account inside Corridor, and whether partners ever see it.

## Decision

**pathUSD is the canonical settlement unit on the hub. The edges accept any USD TIP-20.** Partners never see pathUSD: they are paid in USDC on Base or Solana.

## Consequences

* One atomic swap on Tempo's enshrined stablecoin DEX converts any USD TIP-20 on the way in.
* Vaults pay gas in pathUSD through the Fee AMM, the asset they already hold.
* The Moderato faucet issues pathUSD, so the demo runs on the production asset.
* Across routes `pathUSD (4217) → USDC` on Base and others.
* pathUSD supply is still small. Each corridor carries a `settlementAsset` policy, and a ticket larger than pathUSD depth settles in USDC.e directly. Switching is configuration, not a migration.

## Alternatives rejected

* **USDC.e as the unit everywhere:** deeper today, but not the fee token, and it bypasses the neutral quote token the DEX routes through.
* **Multiple units per customer:** fragments balances and forecasts, which is the problem the hub exists to remove.


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