---
title: "User Guides"
description: "How to trade and provide liquidity on BTR: what each action does on chain, what it costs, and how it can fail."
audience: user
type: guide
status: live
lang: en
updated: "2026-08-29"
publish: true
---

# User Guides

These pages describe what actually happens when you use the app: which contract each action
calls, what you pay, and every way the transaction can be rejected. Each opens with what a holder
needs and then goes down to the call and its revert surface, so the later sections of every page
are as useful to someone reproducing the flow as to someone using it. The mechanism behind the
prices lives in [AIMM](/docs/1-overview); the builder entry points are in the
[Developer Guides](/docs/5-overview).

Behaviour is the same on every chain BTR runs on; the examples below use one deployed instance, where the
roster and addresses are listed under [Deployments](/docs/2-overview).

## Before you start

See [deployed instances](/docs/2-1-contract-addresses) for where BTR runs. Where an instance is a testnet, testnet
assets have no value. The six chains named as targets under
[Deployments](/docs/2-overview#1-testnet-policy) carry no contracts yet.

Gas on Arc is paid in **native USDC**, not in ETH. That has two consequences worth knowing before
your first transaction:

- A wallet holding only pool assets cannot transact.
- "max" on a native USDC balance must leave gas behind, or the send fails.

A new wallet has to arrive funded: the faucet mints pool assets, not gas.

Claim pool assets from the app's **Faucet**, once per token per UTC day; the caps and the
registration step are in [Assets and the Hub](/docs/4-3-assets-and-the-hub#5-the-testnet-faucet).

| Page | Content |
|------|---------|
| [Swapping](/docs/4-1-swapping) | How a route is planned off chain, what the swap transaction calls, what the slippage control protects you against, and the reverts |
| [Providing Liquidity](/docs/4-2-providing-liquidity) | Single-sided deposit, per-leg receipts, the withdraw cooldown, how coverage prices both sides, and liability swaps between legs |
| [Assets and the Hub](/docs/4-3-assets-and-the-hub) | Why every pool has a base asset, native tokens versus their mintable twins, what "listed" means, and the testnet faucet |
| [Liability Swaps](/docs/4-4-liability-swaps) | Moving an LP claim between two legs of one pool without withdrawing: the two haircuts, the mark cap, and where it beats a withdraw-and-redeposit |

Terms used throughout are defined in the [Glossary](/docs/glossary).