> For the complete documentation index, see [llms.txt](https://docs.axis.to/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.axis.to/usdx-the-synthetic-dollar/usdx.md). # What is USDx? USDx, the Axis Dollar, is Axis's synthetic dollar, an upgradeable ERC-20 token. New USDx is created only through the Axis primary market against supported collateral; the token itself grants minting rights to the market alone. ## Minting Minting runs through the **primary market** (`USDxMarket`), which settles signed market orders. A mint order states: * who provides the collateral and who receives USDx; * the collateral asset and amount, and the USDx amount; * an expiry and a one-time nonce. An eligible participant signs the order and an authorized operator submits it for settlement. The market verifies the order, checks capacity, and routes collateral to registered custody before USDx is minted. Mint capacity is bounded by configured caps, a `CapConfig` meters USDx output against a `cap` over a chosen `CapScope` and `WindowType` (for example, per block), and a failed settlement consumes neither the nonce nor the capacity, so a rejected order can be safely retried. Eligibility and access conditions are enforced around the market, not inside the token. ## Redemption Redemption also settles through the primary market. A signed redeem order specifies the USDx to burn and the collateral asset and amount to return; an authorized operator submits it. Settlement depends on order validity, operator availability, the same configured `CapConfig` capacity (metering USDx input), and sufficient collateral available to the market. Redeeming *staked* USDx (sUSDx → USDx) is a separate, asynchronous flow. See [What is sUSDx?](/susdx-the-rewards-vault/susdx.md). ## Token controls USDx is a governed token: every balance-changing transfer routes through a single enforcement point, so these controls apply uniformly. * **Supply** is role-gated, only the primary market may mint (`MARKET_ROLE`, held by `USDxMarket`). * **Bridging** across chains uses dedicated mint/burn under `BRIDGE_ROLE`. * **Pause** (`PAUSER_ROLE`) can halt transfers in an emergency. * **Restrictions** (`RESTRICTION_ROLE`) can block specified addresses from sending, receiving, or spending USDx. These powers serve security and compliance, and they also create administrative and censorship risk. See [Access Control](/reference/access-control.md) and [Disclosures](/resources-and-legal/compliance.md). ## What supports USDx At the contract level, USDx issuance is tied to supported collateral received through the primary market. The contracts enforce which collateral tokens and custody addresses are allowed, but they do not, by themselves, prove the current composition, value, liquidity, or safety of assets held outside the contracts. Where does the yield come from? The collateral backing USDx is deployed into market-neutral strategies whose structural edge is cross-venue and cross-asset fragmentation, a durable yield source that does not rely on any single mechanism. Funding is one component (and can be the larger share in a given period); see the Transparency Dashboard for current attribution. That yield is passed to stakers through sUSDx, not to USDx holders directly, since holding USDx alone earns nothing. That distinction matters: **onchain issuance controls are not the same as a real-time proof of reserves or a guarantee of redemption.** See [Backing, Custody & Transparency](/backing-reserves-and-transparency/backing-custody-transparency.md). ## USDx versus sUSDx | | USDx | sUSDx | | ----------------- | ------------------------------------------- | ------------------------------------------------- | | Type | Synthetic-dollar token (ERC-20) | Rewards vault position (ERC-4626) | | Primary purpose | Transfer, hold, stake, or redeem | Accrue vested rewards paid to the vault | | Value measured by | Market price and redemption terms | USDx assets per sUSDx position (exchange rate) | | Staking yield | No | Variable; depends on rewards delivered and vested | | Exit | Submit a redeem order to the primary market | Request redemption (async), then claim USDx | ## What USDx does not guarantee USDx does not guarantee: * a market price of exactly $1 at every moment; * immediate or unlimited minting or redemption; * secondary-market liquidity; * the absence of custody, counterparty, or strategy losses. Read [How USDx Targets $1](/usdx-the-synthetic-dollar/peg-stability.md) for the mechanism and [Risk Overview](/risk/risk-overview.md) for its failure modes. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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