> ## 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.

# Architecture overview

> Key components of the Fuego codebase and how they interact.

Fuego is a C++17 CryptoNote-based blockchain with significant extensions for commitment deposits, adaptor-signature atomic swaps, and zero-knowledge proofs.

## Core components

| Component       | Path                                   | Description                                 |
| --------------- | -------------------------------------- | ------------------------------------------- |
| Blockchain      | `src/CryptoNoteCore/Blockchain.cpp`    | Consensus, fee pool, epoch accounting       |
| CommitmentIndex | `src/CryptoNoteCore/CommitmentIndex.*` | CD state tracking, epoch reports            |
| Currency        | `src/CryptoNoteCore/Currency.*`        | `calculateCdInterest()`, network parameters |
| WalletGreen     | `src/Wallet/WalletGreen.*`             | Wallet operations, deposit management       |
| RpcServer       | `src/Rpc/RpcServer.*`                  | HTTP JSON-RPC endpoints                     |
| SwapDaemon      | `src/SwapDaemon/`                      | Adaptor-signature swap state machine        |
| AliasIndex      | `src/CryptoNoteCore/AliasIndex.*`      | On-chain alias registry                     |

## Transaction types

Fuego extends CryptoNote with custom transaction inputs and outputs:

| Type                                 | Tag | Description                                 |
| ------------------------------------ | --- | ------------------------------------------- |
| `TransactionOutputCommitment`        | —   | Creates a CD or burn deposit                |
| `TransactionInputCommitmentSpend`    | 0x7 | Spends a mature CD (with `claimedInterest`) |
| `TransactionInputCommitmentTransfer` | 0x8 | Transfers a CD before maturity              |

See `include/CryptoNote.h` for full struct definitions.

## Fee pool mechanics (live constants)

1. XFG-side atomic swaps charge **1%** (`SWAP_FEE_RATE_BPS`); epoch split **69% CD / 11% Bonus Vault / 20% Treasury**
2. Hearth trades charge **1%** (`HEARTH_FEE_BPS`); **100% → CD yield** (LPs earn the swap spread)
3. At epoch boundaries (`EPOCH_DURATION_BLOCKS = 900` mainnet), fee accounting advances for HEAT CDs
4. Product path: burn XFG → mint HEAT (`mintHeatV10`) → lock HEAT as CD — see [dual-asset architecture](/fuego-dual-asset-architecture)

## Related public docs

* [How CDs work](/features/commitment-deposits/how-cds-work)
* [How Hearth works](/features/hearth/how-hearth-works)
* [swapXFG](/features/atomic-swaps/how-swaps-work)
* [Fee pool API](/api-reference/fee-pool)

Internal design notes also exist under the monorepo `docs/` tree (implementation plans, zkLP research) but are not published as Mintlify pages.