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

# Fee Pipeline

> How fees flow through FeeCollector, FeeSwapper, and ContributorSplit

## Overview

The protocol uses a two-step fee pipeline with explicit fee-kind routing. All protocol and app fees flow through the same contracts, but are routed differently based on their `FeeKind`.

```mermaid theme={null}
flowchart LR
    subgraph sources ["Fee Sources"]
        BC["AppBondingCurve<br/>(TRADING_FEE)"]
        AT["AppToken<br/>(TRANSFER_TAX)"]
        AF["AppFactory<br/>(LAUNCH_FEE)"]
        MOD["App Modules<br/>(CONTENT_SALE, TOURNAMENT_FEE, OTHER)"]
    end
    subgraph pipeline ["Pipeline"]
        FC["FeeCollector"]
        FS["FeeSwapper"]
    end
    subgraph destinations ["Destinations"]
        TR["Treasury"]
        CS["ContributorSplit"]
    end
    BC --> FC
    AT --> FC
    AF --> FC
    MOD --> FC
    FC --> FS
    FS --> TR
    FS --> CS
```

***

## FeeKind Enum

Every fee is tagged with a `FeeKind` that determines routing:

| FeeKind          | Value | Routing                         |
| ---------------- | ----- | ------------------------------- |
| `LAUNCH_FEE`     | 0     | 100% treasury                   |
| `TRADING_FEE`    | 1     | 80% contributors / 20% treasury |
| `TRANSFER_TAX`   | 2     | 80% contributors / 20% treasury |
| `CONTENT_SALE`   | 3     | 80% contributors / 20% treasury |
| `TOURNAMENT_FEE` | 4     | 80% contributors / 20% treasury |
| `OTHER`          | 5     | 80% contributors / 20% treasury |

The default treasury take for app-revenue fee kinds is `2000 bps` (20%), configurable per-app by governance.

***

## FeeCollector

`FeeCollector` is the accounting layer. It tracks pending fee balances indexed by `(appId, FeeKind, asset)`.

**Key behavior:**

* Receives ELTA deposits via `depositElta(appId, kind, amount)`
* Receives app token deposits for transfer tax
* Sweeps accumulated balances to `FeeSwapper` via `sweep(appId, kind, asset)`
* Sweeping is permissionless — anyone can trigger it

***

## FeeSwapper

`FeeSwapper` (implementing `IFeeRouterV2`) applies the routing policy:

1. If the app is **paused** in `AppRegistry` → 100% treasury
2. If the fee kind is `LAUNCH_FEE` → 100% treasury
3. Otherwise (app-revenue kinds):
   * `treasuryAmount = amount * takeBps / 10_000`
   * `contributorAmount = amount - treasuryAmount`
   * Treasury portion is sent to the protocol treasury
   * Contributor portion is forwarded to the app's `ContributorSplit`

**Defaults:**

* `defaultTreasuryTakeBps`: 2000 (20%)
* Per-app override via `appTreasuryTakeBps[appId]` (if non-zero)
* `minSwapThreshold`: 1 ELTA (minimum for swap operations)

***

## ContributorSplit

Each app has a `ContributorSplit` contract deployed at registration. It implements pull-based payouts to named contributors.

* **Shares-based**: each contributor has a share weight; payouts are proportional
* **Max 200 contributors** (factory default, governance-configurable)
* **Pull claims**: contributors call `release(asset, account)` to claim
* **Locked on first payment**: contributor list is locked once the first non-zero payment is received
* **Owner safe controlled**: only the app's owner safe can set contributors via `setContributors()`

```mermaid theme={null}
flowchart TB
    FS["FeeSwapper"] -->|"deposit app revenue"| CS["ContributorSplit"]
    SAFE["App Owner Safe"] -->|"setContributors()"| CS
    CS -->|"release(asset, me)"| C1["Contributor A"]
    CS -->|"release(asset, me)"| C2["Contributor B"]
    CS -->|"release(asset, me)"| CN["Contributor N"]
```

***

## FeeManager (Epoch Settlement)

`FeeManager` provides an alternative epoch-based settlement flow with USDC conversion:

* Epochs are time-bounded settlement windows (default 1 day, configurable 1 hour to 7 days)
* Caller incentive: 0.10% of USDC balance (max 25 USDC) when balance exceeds 100 USDC
* Settles accumulated fees by swapping to USDC and depositing into `TreasuryUSDCVault`
* Tracks per-app and per-epoch revenue

**FeeManager splits** (separate from FeeSwapper routing):

| Recipient      | Default bps |
| -------------- | ----------- |
| App stakers    | 4500 (45%)  |
| veELTA holders | 3000 (30%)  |
| Creator        | 1000 (10%)  |
| Treasury       | 1000 (10%)  |
| Referral       | 500 (5%)    |

<Note>
  `FeeManager` splits and `FeeSwapper` routing are parallel systems. The active fee path depends on deployment configuration. Consult deployment artifacts for which pipeline is active in your environment.
</Note>

***

## TreasuryUSDCVault

Holds USDC for the protocol treasury when epoch settlement is active:

* Receives deposits from `FeeManager` with `deposit(appId, amount, epochId)`
* Tracks `totalRevenue`, `revenueByApp[appId]`, `revenueByEpoch[epochId]`
* Only the treasury multisig can withdraw