# frxUSD Redemption & Minting Integration Request

**URL:** <https://forum.cow.fi/t/frxusd-redemption-minting-integration-request/3138>\
**Category:** Technical\
**Tags:** solvers\
**Created:** [August 4, 2025, 2:57pm UTC](https://forum.cow.fi/t/frxusd-redemption-minting-integration-request/3138 "2025-08-04T14:57:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![denett](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.cow.fi/denett/32/1470_2.png) [@denett](https://forum.cow.fi/u/denett)\
**Post date:** [August 4, 2025, 2:57pm UTC](https://forum.cow.fi/t/frxusd-redemption-minting-integration-request/3138/1 "2025-08-04T14:57:07Z")

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## **Title**

Integration of **frxUSD ↔ USDC and USTB** Redemption & Minting via ERC‑4626‑Compatible Custodian and RWA Redemption Paths on the **Ethereum** chain.

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## **Author**

Frax team  
Contact via telegram: @denett4

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## **Simple Summary**

This proposal details integration with Frax’s on‑chain flow that enables direct swaps between **frxUSD ↔ USDC** and redemption of **frxUSD** via **USTB → USDC**. It leverages ERC‑4626 compatible custodian contracts (USDC and USTB) and the **RWARedemptionCoordinator** for seamless settlement.

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## **Motivation**

- **Unique Value** : On‑chain, permissionless swaps between frxUSD and USDC; plus real‑world collateral (USTB) redemption support.

- **Settlement Quality** : Efficient redemption paths with real‑time quoting via preview functions; fallbacks via RWA coordinator.

- **Supported Pairs** : frxUSD/USDC native; frxUSD → USTB → USDC via coordinator.

- **Liquidity & Volume** : The USDC Custodian has $10M in mint and up to $500k in redeem liquidity. The USTB path has $10M in redeem liquidity. Volume has been $600k in the last 24h.

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## **Technical Specification**

### **Price Discovery**

- **On‑chain quoting** :

### **Settlement Interface**

#### **Custodian Contracts (Ethereum Mainnet)**

- **USDC custodian** (“frxUSD‑USDC Custodian Proxy”)

- **USTB custodian** (“frxUSD‑USTB Custodian Proxy”)

#### **RWA Redemption Coordinator**

- **RWARedemptionCoordinator Proxy**

#### **Example transactions:**

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  - Deposit: [0x444170ea6e0375a17b21de2340030ebeff9a7ff388c591e28950ae8705fbe80b](https://etherscan.io/tx/0x444170ea6e0375a17b21de2340030ebeff9a7ff388c591e28950ae8705fbe80b)

  - Redeem: [0x8e4cb56050b1b3481c51605908388024546eed9f73ead02fc2b0bbd4ba622969](https://etherscan.io/tx/0x8e4cb56050b1b3481c51605908388024546eed9f73ead02fc2b0bbd4ba622969)

  - RedeemRWA: 0x9bf8b6a4cafe562bba2865282722c0fa083014d2cfc35ae1b65d867d2ab35935

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## **Additional Information**

- **Limitations** :

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## **Contact Information**

- Technical Support via telegram: @denett4

- Expected Response: 24h on technical queries

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<div class="post-metadata">

**Author:** ![mfw78](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.cow.fi/mfw78/32/1598_2.png) [@mfw78](https://forum.cow.fi/u/mfw78)\
**Post date:** [August 15, 2025, 11:15am UTC](https://forum.cow.fi/t/frxusd-redemption-minting-integration-request/3138/2 "2025-08-15T11:15:49Z")

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Hi, thanks for the information here. I’m not sure about the efficacy of advertising these routes / integration here, but they are certainly good to be somewhere other than nowhere. There are alternatively discord channels (a dedicated solvers channel) where you can raise solver related issues that may get escalated via the team to solvers, though for route integration, this is less common a thoroughfare for these kinds of things.

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**Author:** ![middleway.eth](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.cow.fi/middleway.eth/32/12_2.png) [@middleway.eth](https://forum.cow.fi/u/middleway.eth)\
**Post date:** [August 19, 2025, 4:13pm UTC](https://forum.cow.fi/t/frxusd-redemption-minting-integration-request/3138/3 "2025-08-19T16:13:35Z")

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I’ve asked to post here so it doesn’t sit on silo’d groups.  
Would def be open to suggestions for how to make this info most visible and accessible to solvers.