> For the complete documentation index, see [llms.txt](https://docs.primefi.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.primefi.xyz/v3-markets/fathom-v3.md).

# Fathom v3 (XDC)

The PrimeFi app header has a **v2 / v3** toggle. This page explains what **v3** means.

### TL;DR

* **v2 = PrimeFi.** Operated by Prime Numbers Labs on Base, HyperEVM and XDC. This is the protocol the rest of this documentation describes.
* **v3 = Fathom Lending.** A separate, third-party Aave v3 fork operated by **Fathom Protocol** on the XDC network. PrimeFi surfaces it inside our app as a convenience so users can access both markets from one interface, but **PrimeFi does not operate, custody or take responsibility for the v3 contracts**.

{% hint style="info" %}
For anything related to Fathom v3 (supply, borrow, collateral, health factor, liquidations, oracle questions, contract addresses, audits, support tickets), please use the official **Fathom Lending** documentation and support channels — not PrimeFi's.
{% endhint %}

### Fathom Lending — official resources

| What you need                        | Where to go                                                                                                                                                    |
| ------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Lending docs (root)**              | [docs.fathom.fi/lending](https://docs.fathom.fi/lending/)                                                                                                      |
| **XDC deployment & contract list**   | [docs.fathom.fi/lending/deployments/xdc-network](https://docs.fathom.fi/lending/deployments/xdc-network)                                                       |
| **How to supply / borrow / repay**   | [docs.fathom.fi/lending/user-guides/supply-borrow-repay-and-withdraw-asset](https://docs.fathom.fi/lending/user-guides/supply-borrow-repay-and-withdraw-asset) |
| **FXD stablecoin (related product)** | [docs.fathom.fi/fxd-stablecoin](https://docs.fathom.fi/fxd-stablecoin/)                                                                                        |
| **Fathom dApp**                      | [app.fathom.fi](https://app.fathom.fi/)                                                                                                                        |

### What's different between v2 and v3 inside the PrimeFi UI

| Feature                              | PrimeFi (v2)                                       | Fathom (v3)                                                |
| ------------------------------------ | -------------------------------------------------- | ---------------------------------------------------------- |
| Chains                               | Base, HyperEVM, XDC                                | XDC only                                                   |
| Underlying protocol                  | PrimeFi (Aave v2 fork + omnichain layer)           | Fathom Lending (Aave v3 fork)                              |
| Reserves                             | USDC, USDT, ETH, HYPE, WBTC, XDC, PSXDC, PRFI etc. | FXD, FTHM, WXDC and other Fathom reserves                  |
| pLP boost / PRFI emissions           | Yes (where chef is active — currently Base)        | **No** — Fathom has its own incentive model                |
| Cross-chain borrow (Stargate)        | Yes                                                | No                                                         |
| Auto-compound / vesting / locked pLP | Yes                                                | No                                                         |
| Prime Points eligibility             | Yes                                                | No                                                         |
| Smart contract operator              | Prime Numbers Labs                                 | Fathom Protocol                                            |
| Audits                               | See [Audits](/reference/audits.md)                 | Halborn Formal Verification (March 2026) — see Fathom docs |

### How to switch versions

Open the PrimeFi app, look at the header on the top right, and click the **v2 / v3** pill. The app will:

1. Update the active market and reserves list.
2. Switch your wallet to the appropriate chain (XDC for v3).
3. Hide PrimeFi-specific surfaces that don't apply to Fathom (pLP tabs, Prime Points, Flik, Prepaid Gas).

If you're on a PrimeFi-only page like `/plp` or `/prime-points` when you toggle to v3, the app will bounce you to the Dashboard.

### Contract addresses

* **PrimeFi v2 contracts** are documented under [Smart Contracts Addresses](/reference/smart-contracts-addresses.md).
* **Fathom v3 contracts** are listed in the [Fathom XDC deployment doc](/reference/smart-contracts-addresses/fathom-xdc-deployment-addresses.md), with the canonical source being [Fathom's own deployment page](https://docs.fathom.fi/lending/deployments/xdc-network).