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

# RentrEscrow Overview

> The Solidity contract that holds rental funds between checkout and settlement.

## What it does

`RentrEscrow` is a single-file Solidity contract on [Base](https://base.org) that escrows USDC for the duration of every rental. It has three external entrypoints:

| Function                                              | Caller   | When                                                      |
| ----------------------------------------------------- | -------- | --------------------------------------------------------- |
| `createRental(rentalId, owner, amount, fee, endTime)` | Renter   | At checkout. Pulls `amount + fee` USDC into the contract. |
| `release(rentalId)`                                   | Operator | At rental end — pays owner + treasury.                    |
| `refund(rentalId)`                                    | Operator | On a successful dispute — returns full deposit to renter. |

## Design choices

* **Single 256-bit storage slot per rental.** Owner address (160 bits), amount (96 bits), fee (96 bits), endTime (64 bits), status (8 bits) — packed for gas efficiency.
* **Custom errors over revert strings.** Cheaper, more informative.
* **Checks-Effects-Interactions** pattern throughout. No reentrancy attack surface.
* **`_safeTransferFrom` / `_safeTransfer` wrappers** for ERC-20 — handles tokens that return false vs. revert (USDC follows the standard but defensive coding is free).
* **Admin can rotate operator** via `setOperator()` — meant for migrating from hot relayer to multisig.
* **No pause / kill switch.** Intentional — keeps the trust surface minimal. If we ever want one, we'd add it before going to mainnet.

## Roles

| Role     | Default value                     | Can do                                                     |
| -------- | --------------------------------- | ---------------------------------------------------------- |
| Renter   | Whoever called `createRental`     | Nothing post-creation; the contract is the source of truth |
| Owner    | Set at `createRental` time        | Nothing — funds get pushed to them, no pull needed         |
| Operator | Backend EOA (or multisig in prod) | Call `release` and `refund` anytime                        |
| Admin    | Backend EOA (or multisig)         | Rotate the operator                                        |
| Treasury | Set at deploy time                | Receives the 1 USDC platform fee per release               |

The contract has **no upgradability**. To change behavior, deploy a new contract and migrate. This trades flexibility for security — no admin can suddenly drain funds via a backdoor.

## Lifecycle

See the [lifecycle page](/contract/lifecycle) for diagrams and step-by-step state transitions.

## Source code

Open source, MIT licensed: [github.com/justexo-hash/rentr/tree/main/programs/rentr-escrow-evm](https://github.com/justexo-hash/rentr/tree/main/programs/rentr-escrow-evm)

Built with [Foundry](https://book.getfoundry.sh/). 20 tests pass (14 unit + 1 fuzz pass over create/release/refund).

## Addresses

See [addresses](/contract/addresses) for deployed contract addresses on Base mainnet and Base Sepolia.

## Security

See [security](/contract/security) for the audit status (currently unaudited) and what we've done in lieu of an external review.