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XAUE Technical Document
XAUE is an RWA share token protocol deployed on Ethereum Mainnet, with Tether Gold (XAUt) as its underlying asset.
1. Overview
The XAUE protocol consists of three core contracts:
- FundToken : the XAUE share token contract, responsible for share issuance, redemption requests, and related access control
- Oracle : the contract that manages NAV-related parameters and APR settings
- Vault : the custody contract for the underlying asset, responsible for controlled outflows
Underlying asset:
- XAUt : Tether Gold
2. Network Information
| Item | Value |
|---|---|
| Network | Ethereum Mainnet |
| Chain Type | EVM |
| Underlying Asset | Tether Gold (XAUt) |
3. Mainnet Contract Addresses
| Module | Address |
|---|---|
| XAUE / FundToken | 0xd5D6840ed95F58FAf537865DcA15D5f99195F87a |
| Oracle | 0x0618BD112C396060d2b37B537b3d92e757644169 |
| Vault | 0xC86Daf84C01c891B21dEA66f4cA41CD3799f9E6B |
| Underlying XAUt | 0x68749665FF8D2d112Fa859AA293F07A622782F38 |
| Custody / Reserve Address | 0x07cd80c066e13679a70e125c76f76e796c8bc748 |
4. Token Information
4.1 XAUE
| Item | Value |
|---|---|
| Name | XAU Reward Token |
| Symbol | XAUE |
| Decimals | 18 |
4.2 XAUt
| Item | Value |
|---|---|
| Name | Tether Gold |
| Symbol | XAUt |
| Decimals | 6 |
5. Core Deployment Parameters
5.1 Oracle Parameters
| Parameter | On-chain Value | Human-readable Meaning |
|---|---|---|
| baseNetValue | 1000000000000000 | 1e15 |
| maxAPR | 100000000000000000 | Maximum APR is 10% |
| maxAprDelta | 50000000000000000 | Maximum single APR change is 5% |
| minUpdateInterval | 86400 | Minimum update interval is 1 day |
5.2 Initial FundToken Parameters
The following values reflect the protocol's initial deployment configuration and may be updated over time through governance or operational decisions.
| Parameter | On-chain Value | Human-readable Meaning |
|---|---|---|
| minDepositAmount | 1000 | Initial minimum subscription amount is 0.001 XAUt |
| minRedeemShares | 1000000000000000000 | Initial minimum redemption amount is 1 XAUE |
6. Decimal Conventions
The protocol uses three common precision standards:
| Item | Precision |
|---|---|
| XAUt | 6 decimals |
| XAUE | 18 decimals |
| NAV / APR parameters | 1e18 precision |
7. Initial Pricing Reference
Under the current design baseline where baseNetValue = 1e15 :
- 1 XAUt = 1000 XAUE
This serves as the initial pricing reference at deployment.
8. Oracle Calculation Model
The Oracle calculates the latest NAV using a linear interpolation model based on APR.
8.1 Core Variables
| Variable | Meaning |
|---|---|
| baseNetValue | NAV at the start of the current period, with 1e18 precision |
| currentAPR | Current annual percentage rate, with 1e18 precision |
| lastUpdateTimestamp | Timestamp marking the beginning of the current period |
| maxAPR | Maximum allowed APR |
| maxAprDelta | Maximum allowed APR change per update |
| minUpdateInterval | Minimum time interval between updates |
8.2 Formula
The Oracle computes the current NAV using the following formula:
NAV(t) = baseNetValue + baseNetValue × currentAPR × (t - lastUpdateTimestamp) / (365 days × 1e18)
Where:
- t is the current block timestamp
- baseNetValue is the NAV at the start of the current period
- currentAPR is the APR effective during the current period
Under this model, NAV grows linearly within each period.
8.3 Update Logic
When a new APR is submitted, the Oracle first crystallizes the current interpolated NAV into a new baseNetValue , and then updates:
- lastUpdateTimestamp
- currentAPR
This ensures that accrued value from the previous period is preserved before the new APR takes effect.
8.4 Constraints
APR updates must satisfy the following constraints:
- the new APR must not exceed maxAPR
- the difference between the new APR and the current APR must not exceed maxAprDelta
- the time interval between two updates must not be shorter than minUpdateInterval
9. Oracle Read Interfaces
The Oracle exposes the following core read interfaces:
9.1 getLatestPrice()
Returns the latest NAV at the current point in time.
- Return type: uint256
- Precision: 1e18
This value is the primary on-chain pricing reference for XAUE shares.
9.2 Other Common Read Parameters
| Interface | Description |
|---|---|
| baseNetValue() | Returns the NAV at the start of the current period |
| currentAPR() | Returns the current APR |
| lastUpdateTimestamp() | Returns the timestamp of the latest period start |
| maxAPR() | Returns the maximum allowed APR |
| maxAprDelta() | Returns the maximum single APR change |
| minUpdateInterval() | Returns the minimum update interval |
10. System Architecture
FundToken
FundToken is responsible for:
- managing the XAUE share token
- controlling the user whitelist
- processing redemption requests and approval states
- coordinating with the Oracle and Vault for subscriptions and redemptions
Oracle
Oracle is responsible for:
- maintaining NAV-related parameters
- enforcing APR update constraints
- controlling the update frequency of pricing inputs
- serving as the pricing parameter source for the protocol
Vault
Vault is responsible for:
- custody of the underlying XAUt asset
- controlled asset transfers to whitelisted destination addresses
- serving as the source of funds for redemption settlement
11. Access Control and Governance
The protocol uses role-based access control governed by multisig-managed administration.
Primary roles include:
- DEFAULT_ADMIN_ROLE
- MANAGER_ROLE
- REDEMPTION_APPROVER_ROLE
- EMERGENCY_GUARDIAN_ROLE
- NAV_UPDATER_ROLE
- SETTLEMENT_OPERATOR_ROLE
Operational constraints include:
- subscriptions, redemptions, and transfers are subject to whitelist rules
- Oracle parameter updates are constrained by frequency and delta limits
- Vault outflows require both role authorization and destination whitelist checks
- critical configuration is controlled through multisig governance
12. Notes
This document provides a public overview of protocol configuration and mainnet deployment parameters.
In the event of future upgrades, governance changes, or parameter updates, the latest on-chain state and official disclosures should prevail.