> ## Documentation Index
> Fetch the complete documentation index at: https://docs.trdrs.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Paper accounts on provider contracts

> Issue paper accounts that trade a provider's own contract: its collateral asset, leverage tiers, margin modes, funding and liquidation.

A venue can issue paper accounts that trade a provider's contract the way the provider trades it.
The account is held in the asset the contract settles in, and the paper book applies the
provider's own leverage tiers, margin modes, funding and liquidation line, read from the
provider. The paper book supports this for Hyperliquid's perpetuals on a standard mainnet account.

## Hold the account in the provider's asset

An account holds only contracts that settle in its own currency, and its risk policy converts no
asset into another. Issue accounts in the provider's own collateral asset:

| Provider | Contract | Account currency |
| - | - | - |
| Hyperliquid | `native-perpetual-oracle-funding-v2`: priced in USDT (HYPE and PURR in USDC), paid and collateralized in USDC, funded on Hyperliquid's oracle price | USDC |
| Binance, Bybit | The exchange's USDT perpetual | USDT |
| A futures provider | The exchange's contract | USD |

List a Hyperliquid perpetual with `contractVersion: "native-perpetual-oracle-funding-v2"`, the
version the contract reference lookup proposes for it. Publish the [risk policy](/guides/venue-accounts)
with `currency` set to the account currency and its `posting` term stating that currency's
precision.

## Margin a contract by the provider's profile

Set the crypto derivative class's margin to the provider's profile:

```json theme={null}
{
  "basis": "provider_profile",
  "reservation": "gross_pending_initial",
  "contracts": [{
    "contract": "HYPERLIQUID:BTC",
    "providerId": "hyperliquid",
    "network": "mainnet",
    "accountModel": "standard",
    "binding": {
      "profileDigest": null,
      "maxAgeMs": 172800000,
      "firm": { "maxLeverage": null, "modes": null, "selection": { "kind": "trader", "leverage": 1 } }
    }
  }]
}
```

The paper book reads Hyperliquid's perpetual metadata (`POST https://api.hyperliquid.xyz/info`
with `{"type": "meta"}`) every minute and records each perpetual's profile, its leverage tiers and
margin modes, when it changes and at least every hour. A contract trades under the newest profile
recorded no longer than `maxAgeMs` ago. With `profileDigest` set, it trades only under that one
profile: when Hyperliquid changes its terms, new exposure on the contract is refused until you
publish the new digest. Without a fresh profile, new exposure is refused; nothing falls back to a
flat rate.

The firm's limits narrow the provider's and never widen them. `maxLeverage` caps the leverage
and `modes` names the margin modes the account may use, each `null` for no limit of your own.
`selection` is either `{ "kind": "trader", "leverage": n }`, where the trader chooses within the
limits and starts at `n` in the first mode the contract offers, cross before isolated, or
`{ "kind": "fixed", "leverage": n, "marginMode": "cross" }`, which holds every account to that one
setting. A contract no row names is not offered on the account.

## Leverage and margin mode

The trader reads and sets them through the Trading API, as on any provider:
`GET /api/trading/symbol-config` answers the leverage, the margin mode, the most leverage allowed,
the modes offered and whether a change is possible now; `PUT /api/trading/symbol-config` sets the
leverage and `PUT /api/trading/margin-mode` the margin mode. Hyperliquid sets both per
instrument, so a change reaches that instrument alone. It is refused while the instrument holds a
position, a working order or a charge still owed, and while the account is being liquidated.

## Collateral

The account's balance sits in Hyperliquid's cross pool. A cross position is margined by the
whole pool. An isolated position's initial margin moves from the cross pool to its own isolated
pool as its entry fills, and returns to the cross pool once the position is closed and nothing is
owed on it. The account's balance never changes by these moves.

Working orders reserve the initial margin of the whole held and pending notional at the tier it
reaches, less what the held position already requires, so a tier boundary is never stepped over by
a resting order. A reduce-only order reserves nothing.

## Funding and liquidation

Funding is charged hourly on Hyperliquid's settled rate, on the position's notional at
Hyperliquid's oracle price, as [Hyperliquid's funding page](https://hyperliquid.gitbook.io/hyperliquid-docs/trading/funding)
states; a positive rate is paid by longs. An isolated position's funding is charged to its own
pool.

Maintenance margin follows [Hyperliquid's margin tiers](https://hyperliquid.gitbook.io/hyperliquid-docs/trading/margin-tiers):
the notional at the mark price times the tier's maintenance rate, less its maintenance deduction.
The cross pool and each isolated pool are valued on their own, and a pool whose equity falls to its
maintenance line is liquidated alone.

## What the paper book does not model

Unified accounts, portfolio margin, HIP-3 perpetual dexes, inverse contracts and independent
tickets are refused. Margin cannot be added to or removed from an open isolated position.
Hyperliquid's partial liquidation of large positions and its backstop liquidation vault are not
modeled: a liquidated pool's positions are closed whole, and a loss beyond an isolated pool's
margin is taken from the cross pool. The paper book provides the contract's rules, not the
exchange's custody, fill liquidity or fee tiers.


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.