Exchange endpoint

All state-changing actions are sent to POST /exchange as signed payloads. The action.type field selects the operation.

Sign every request

The exchange endpoint rejects unsigned actions. Use an API wallet and never expose the master key to a client.

Asset IDs

Perpetuals: the index in the universe array from meta.
Spot: 10000 + index in spotMeta.universe.
Outcome markets: 20000 + index.

See assets and tick sizes for a worked example.

Place an order

POST/exchangeSignedWeight 4

Place one or more orders. Orders in one request are matched in sequence.

Request body

Name	Type	Required	Description
`orders`	array	Yes	One or more order objects.
`orders[].asset`	integer	Yes	Asset ID.
`orders[].isBuy`	boolean	Yes	True for buy/long, false for sell/short.
`orders[].limitPx`	string	Yes	Limit price; required even for market orders (use a far price).
`orders[].sz`	string	Yes	Size in base units.
`orders[].reduceOnly`	boolean	Yes	Prevent the order from increasing or flipping the position.
`orders[].tif`	string	Yes	Gtc, Ioc, or Alo.
`orders[].cloid`	string	No	128-bit hex client order ID.
`grouping`	string	Yes	na, normalTpsl, or positionTpsl.

code

curl -s https://api.nexwest.app/exchange \
  -H "Content-Type: application/json" \
  -d '{
    "action": {
      "type": "order",
      "orders": [{
        "asset": 0,
        "isBuy": true,
        "limitPx": "104000",
        "sz": "0.01",
        "reduceOnly": false,
        "tif": "Gtc"
      }],
      "grouping": "na"
    },
    "nonce": 1762732800123,
    "signature": { "r": "0x...", "s": "0x...", "v": 27 }
  }'

code

const result = await nx.exchange.placeOrder({
  asset: 0,
  isBuy: true,
  limitPx: "104000",
  sz: "0.01",
  reduceOnly: false,
  tif: "Gtc",
});

The response contains statuses with one entry per order: resting, filled, or error.

Cancel orders

POST/exchangeSignedWeight 2

Cancel up to 100 orders by order ID.

code

{
  "type": "cancel",
  "cancels": [{ "asset": 0, "oid": 91490942 }]
}

Use cancelByCloid when you track client order IDs. Use scheduleCancel to set a dead-man's switch: if no action is received before time, all open orders are canceled.

Modify an order

POST/exchangeSignedWeight 3

Change the price or size of a resting order without losing queue priority.

Modifying an order preserves its oid but may reset time priority if the price changes. A modify that would cross the book is rejected.

Leverage and margin

Action	Fields	Notes
`updateLeverage`	`asset`, `isCross`, `leverage`	Leverage is an integer; cannot exceed market max
`updateIsolatedMargin`	`asset`, `isBuy`, `ntli`	Positive adds margin, negative removes
`usdClassTransfer`	`n`, `toPerp`	Move USDC between spot and perps
`subAccountTransfer`	`subAccountUser`, `usd`, `direction`	Move USDC to or from a sub-account

Expiry and rate limits

Some actions accept expiresAfter (milliseconds). User-signed actions such as usdClassTransfer do not. An expired action is rejected and consumes 5x the usual address weight.

Batched requests consume weight per action. See rate limits.

Exchange endpoint

Asset IDs

Place an order

Cancel orders

Modify an order

Leverage and margin

Expiry and rate limits

Related