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

# Fixed Rate Lending

> Cross-chain gasless fixed-rate lending and borrowing

<Frame>
  <img src="https://mintlify.s3.us-west-1.amazonaws.com/centuari/assets/gifs/fixed-rate-overview.gif" alt="Fixed rate lending overview showing order book matching between lenders and borrowers" />
</Frame>

## Overview

Centuari's Fixed Rate Lending is the core product that enables predictable yields for lenders and predictable costs for borrowers. All transactions are gasless and cross-chain by default.

<Info>
  **Key Innovation**: Unlike variable-rate protocols where rates change constantly, Centuari locks in your rate at the moment of execution. Your 8% APY stays 8% APY, period.
</Info>

## Core Features

### Gasless Transactions

No gas fees for users. Confirm your order and we handle the rest.

### Cross-Chain by Default

Deposit and withdraw on any supported chain. Liquidity bridges to Arbitrum automatically where orders are matched and settled. [See cross-chain architecture details](/overview/how-it-works).

### Tokenized Positions (CBT)

When you lend, you receive **Centuari Bond Tokens (CBT)**, tokenized representations of your lending position.

<Card title="Learn about CBT" icon="coins" href="./cbt">
  Understand how CBT works and why it matters for composability
</Card>

## Two Ways to Trade

| Feature               | Easy Mode           | Advanced Mode                      |
| --------------------- | ------------------- | ---------------------------------- |
| Rate selection        | Auto-optimized      | You choose exact rate              |
| Maturity              | Next available date | Predetermined dates (1st of month) |
| Auto rollover         | On by default       | Off by default                     |
| Auto refinance        | On by default       | Off by default                     |
| Order book visibility | Hidden              | Full access                        |
| Partial fill control  | Automatic           | Manual                             |

### Easy Mode

Easy Mode is for users who want fixed-rate exposure without complexity. One click, predictable yields.

<Steps>
  <Step title="Select Asset & Amount">
    Choose your stablecoin and how much to lend or borrow
  </Step>

  <Step title="One-Click Confirm">
    The protocol handles the rest: optimal rate selected, next available maturity date, auto features enabled by default
  </Step>

  <Step title="Position Active">
    Lenders receive CBT tokens. Borrowers receive stablecoins in their wallet. At maturity, positions auto-extend unless you opt out.
  </Step>
</Steps>

**Rate optimization**: Easy Mode scans the order book and matches you at the best available rate, balancing rate vs time-to-fill.

<CardGroup cols={2}>
  <Card title="Auto Rollover" icon="rotate" href="./auto-rollover">
    Automatic position extension for lenders
  </Card>

  <Card title="Auto Refinance" icon="arrows-rotate" href="./auto-refinance">
    Automatic loan renewal for borrowers
  </Card>
</CardGroup>

### Advanced Mode

Advanced Mode gives you complete control. Set your exact rate, choose your maturity, and decide whether to enable auto features.

<Steps>
  <Step title="Select Asset & Amount">
    Choose your stablecoin and how much to lend or borrow
  </Step>

  <Step title="Set Your Rate">
    Enter your desired fixed APY. View the order book to see current bids, asks, and market depth.
  </Step>

  <Step title="Choose Maturity">
    Select from available predetermined maturity dates (1st of each month, up to 3 active)
  </Step>

  <Step title="Configure Auto Features">
    Toggle auto rollover (lenders) or auto refinance (borrowers) on or off
  </Step>

  <Step title="Submit Order">
    Your order enters the book as a limit or market order
  </Step>
</Steps>

#### Understanding the Order Book

```
═══════════════════════════════════════════════════════════
                  USDC / MATURING JUNE 1
═══════════════════════════════════════════════════════════
  LEND ORDERS (Asks)          │         BORROW ORDERS (Bids)
  ────────────────────────────│────────────────────────────
  $50,000 @ 9.0% APY          │         $30,000 @ 7.0% APY
  $25,000 @ 8.5% APY          │         $45,000 @ 7.5% APY
  $100,000 @ 8.0% APY    ◄────┼────►    $75,000 @ 8.0% APY
  ────────────────────────────│────────────────────────────
         Best Ask: 8.0%       │       Best Bid: 8.0%
═══════════════════════════════════════════════════════════
```

### When to Use Each Mode

<CardGroup cols={2}>
  <Card title="Use Easy Mode" icon="wand-magic-sparkles">
    * Want hands-off fixed-rate exposure
    * Don't want to monitor order books
    * Comfortable with market-optimized rates
    * Prefer automatic position management
  </Card>

  <Card title="Use Advanced Mode" icon="sliders">
    * Need a specific rate (e.g., exactly 10%)
    * Need a specific maturity date
    * Want to see and interact with order book
    * Building algorithmic or institutional strategies
  </Card>
</CardGroup>

### Fees

Both modes share the same fee structure:

* **No gas fees**: All order placement is gasless
* **Protocol fee**: 0.1% of interest earned/paid
* **No premium**: Easy Mode doesn't cost extra

### Early Exit

Don't want to wait for maturity? CBT holders can exit early:

* **Limit order**: Set your price and wait for a match
* **Market order**: Instant exit at current market rate
* **No collateral required**: CBT itself is your position

<Card title="CBT Early Exit" icon="door-open" href="./cbt-early-exit">
  Understand your early exit options
</Card>

## How Matching Works

Centuari uses a **hybrid order book model**. Orders are matched using price-time priority:

1. Best rates match first
2. Among equal rates, earlier orders match first
3. Partial fills are supported

<Info>
  **Off-chain Orders, On-chain Settlement**: Orders are stored and matched off-chain for speed and zero gas costs. Only settlement happens on Arbitrum for security.
</Info>

Orders are placed and matched off-chain at zero gas cost. Only deposits, withdrawals, and settlement happen on-chain (Arbitrum) at very low cost. [See full gas breakdown](/overview/how-it-works).

## Supported Assets

### Lending/Borrowing

| Asset | Status  | Min Order |
| ----- | ------- | --------- |
| USDC  | ✅ Live  | 1 USDC    |
| USDT  | ✅ Live  | 1 USDT    |
| DAI   | ✅ Live  | 1 DAI     |
| EURC  | 🔜 Soon | -         |
| JPYC  | 🔜 Soon | -         |

### Collateral

Multiple crypto and RWA collateral types are supported with varying LTV ratios. [See all collateral types and parameters](/user-guides/borrowers/collateral-types).

## Protocol Parameters

| Parameter           | Value                             |
| ------------------- | --------------------------------- |
| Maturity dates      | Predetermined (1st of each month) |
| Active maturities   | Maximum 3 at any time             |
| Minimum order size  | 1 USD equivalent                  |
| Protocol fee        | 0.1% of interest                  |
| Liquidation penalty | 5%                                |

### Predetermined Maturity Dates

Centuari uses a rolling system of predetermined maturity dates:

* All positions mature on the **1st of the month**
* A maximum of **3 maturity dates** are active at any time
* When the nearest maturity passes, a new one opens (auto-rotate)
* Example: If Jan 1, Feb 1, Mar 1 are active, after Jan 1 passes, Apr 1 opens

## Get Started

<CardGroup cols={2}>
  <Card title="Lender Guide" icon="piggy-bank" href="/user-guides/lenders/getting-started">
    Start earning fixed yields
  </Card>

  <Card title="Borrower Guide" icon="hand-holding-dollar" href="/user-guides/borrowers/getting-started">
    Borrow at predictable rates
  </Card>
</CardGroup>