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

# Dual-asset architecture

> XFG and HEAT roles, mint path, CDs, Hearth, and fee routing.

Fuego’s financial layer is built on two native assets and shared fee plumbing.

## Assets

| Asset    | What it is                            | How you get it                                                |
| -------- | ------------------------------------- | ------------------------------------------------------------- |
| **XFG**  | Base-layer CryptoNote privacy coin    | Mine, receive, atomic swap in                                 |
| **HEAT** | Flatcoin / colored commitment outputs | **Mint** by burning XFG (`mintHeatV10`) priced by Hearth TWAP |

Legacy names that are **not** the current model:

* **Embers\_Heat** / fixed 10M:1 conversion — deprecated; do not use `convertXfgToHeat()` for minting
* **COLD** deposits — removed
* **XFG term deposits as CDs** — removed; CDs lock **HEAT**

## Two-step deposit model

```
1) Mint HEAT     burn XFG → HEAT   (term == HEAT_TERM / mintHeatV10)
2) Open a CD     lock HEAT → yield (term is a real block/epoch length, ≠ HEAT_TERM)
```

Step 2 is the only “deposit” that earns APY. You cannot deposit a deposit, and you cannot skip minting and lock XFG as a CD.

Details: [DEPOSIT\_ARCHITECTURE.md](https://github.com/usexfg/fuego-suite/blob/master/DEPOSIT_ARCHITECTURE.md) (repo) and [How CDs work](/features/commitment-deposits/how-cds-work).

## Hearth

**Hearth** is the on-chain **XFG/HEAT** market (constant-product AMM plus orderbook / depth-band machinery). It:

* Sets the **TWAP / spot rate** used when minting HEAT
* Charges **`HEARTH_FEE_BPS = 100` (1%)** per trade → **100% CD yield accumulator** in consensus code (LPs earn the swap spread, not the fee)

## swapXFG

**swapXFG** (SwapDaemon) is peer-to-peer **cross-chain** atomic swap infrastructure (adaptor signatures / chain clients). Completed XFG-side swaps charge **1%**, split **69% CD yield / 11% Bonus Vault / 20% Treasury**.

## Fee map (code)

| Constant                          | Value  | Meaning                                                            |
| --------------------------------- | ------ | ------------------------------------------------------------------ |
| `SWAP_FEE_RATE_BPS`               | 100    | 1% on XFG atomic-swap side                                         |
| `SWAP_FEE_CD_SHARE_PCT`           | 69     | → CD yield pool                                                    |
| `SWAP_FEE_BONUS_VAULT_PCT`        | 11     | → Bonus Vault                                                      |
| `SWAP_FEE_TREASURY_SHARE_PCT`     | 20     | → Treasury                                                         |
| `HEARTH_FEE_BPS`                  | 100    | 1% Hearth trade fee                                                |
| Hearth split                      | 100/0  | `cdHearthFeeAccumulator += totalFee` (100% CD; LP income = spread) |
| `EPOCH_DURATION_BLOCKS`           | 900    | Mainnet epoch (\~5 days at \~480s blocks)                          |
| `CD_MIN_EPOCHS` / `CD_MAX_EPOCHS` | 6 / 72 | \~1 month … \~1 year HEAT CD terms                                 |

## Mental model

```
          ┌─────────────┐
   mine / │     XFG     │── burn ──► HEAT mint (TWAP)
   swap   └──────┬──────┘              │
                 │                     ▼
                 │              ┌─────────────┐
                 └──── Hearth ──┤    HEAT     │── lock ──► CD yield
                        ▲       └─────────────┘
                        │
              swap fees + Hearth fees
                        │
                        ▼
              CD pool / Bonus / Treasury / LP
```