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

# Introduction

ksUSD is a carry-backed dollar for Solana. Deposit USDC, hold ksUSD, and the share price drifts up as the vault earns carry from three on-chain sources: Phoenix SOL-PERP funding, jitoSOL staking, and USDC lending.

> **Pre-deployment.** Not yet on mainnet. v1 hedges on Phoenix Perps (Ellipsis Labs), posting USDC as margin via Ember with jitoSOL held unlevered as the spot leg. Backtested funding is a proxy, since Phoenix only launched Dec 2025.

* Deposit USDC and mint ksUSD at the current share price.
* Hold: no staking, no claiming. Carry accrues into the price.
* Withdraw anytime: instant up to the liquidity buffer, queued beyond it.

The vault picks its own mode from an on-chain funding signal and rebalances on a schedule, with no manual intervention. See [Strategy & Modes](/how-it-works/strategy-and-modes.md).

***

## How it earns

| Yield source             | Active when             | Mechanism                                                                                                       |
| ------------------------ | ----------------------- | --------------------------------------------------------------------------------------------------------------- |
| Phoenix SOL-PERP funding | Normal basis            | The vault shorts the perp and collects funding while it's positive, delta-neutral against the jitoSOL spot leg. |
| jitoSOL staking yield    | Normal basis            | About 5.8% APR, embedded in the jitoSOL/SOL rate. This is the spot leg of the hedge.                            |
| USDC lending carry       | Buffer, reserve, parked | Lent on the Kamino USDC reserve. The full NAV runs here whenever funding isn't worth harvesting.                |

When funding is thin or negative, the short closes, jitoSOL converts to USDC, and the entire NAV runs as USDC lending until funding rewards the hedge again.

***

## How to use it

```
deposit                  USDC → mint ksUSD at current share price
withdraw_instant         burn ksUSD → USDC from the vault's liquidity buffer
request_withdrawal       burn ksUSD now (locks redemption price), queued for payout
process_withdrawal       permissionless crank — fulfill queued requests in FIFO order
claim_wind_down          (wind-down only) burn ksUSD → pro-rata USDC
```

* The ksUSD share price drifts up over time.
* Performance fees apply only above the high-water mark, at the vault level.
* [Fee structure →](/reference/fees.md)

***

## Why Solana

The strategy needs an on-chain perp it can hedge with, a high-yield LST held for staking, deep USDC lending, and cheap enough fees to rebalance often. On Solana those sit on one chain, close enough to compose. On Ethereum they don't line up: gas makes rebalancing expensive, LST yield, funding, and lending live apart, and the spot leg earns less: jitoSOL runs near \~5.8% on Solana staking plus MEV versus \~3% for Ethereum LSTs. Full detail is in the [whitepaper](/reference/whitepaper.md#iv-why-solana).

***

## Why on-chain carry, not RWA

RWA dollars earn whatever T-bills earn, so their yield rises and falls with interest rates. ksUSD earns from crypto funding, staking, and lending, which move independently of rates. It isn't a higher RWA dollar, it's a different one: uncorrelated to the Fed, and fully on-chain, so you can check the yield and collateral any time instead of trusting an off-chain custodian.

***

## Doc map

**Users:** [Deposit](/keystone-finance/deposit.md) · [Withdraw](/keystone-finance/withdraw.md) · [Check position](/keystone-finance/check-position.md)

**Builders:** [Quick start](/for-developers/quick-start.md) · [Instructions](/for-developers/instructions.md) · [Accounts](/for-developers/accounts.md) · [Events](/for-developers/events.md) · [Errors](/for-developers/errors.md)

**Operators:** [Keeper bot](/for-operators/keeper-bot.md) · [Monitoring](/for-operators/monitoring.md) · [Admin ops](/for-operators/admin-ops.md)

**Reference:** [Whitepaper](/reference/whitepaper.md) · [Historical simulation](/reference/historical-simulation.md) · [Fees](/reference/fees.md) · [NAV & pricing](/reference/nav-calculation.md) · [Security](/reference/security.md) · [Protocols](/reference/protocols.md)

***

## Program

| Network | Program                          | Address                                        |
| ------- | -------------------------------- | ---------------------------------------------- |
| Devnet  | `keystone_finance` (ksUSD vault) | `HvsAc157bJ7Pd4uGr7xssHMifGs6RMbPu14ZMsiEABWT` |
| Mainnet | *new program ID at deploy time*  | Pending audit                                  |