modify: Update an Open Order Price, Size, or TIF

The modify action updates a resting (OPEN status) order without requiring you to cancel and replace it. You can change the price, total size, time-in-force (Gtc or Alo only), and client order ID. Direction (b), contract (a), and reduceOnly (r) cannot be changed — cancel the order and place a new one if you need to alter those fields.

Endpoint

POST https://dev.upsidemax.xyz/exchange
Content-Type: application/json

Priority Rules

How you locate and modify the order determines whether it retains its queue position:

Same price, reduce size only — the modification is applied in-place. The order keeps its existing FIFO queue priority.
Change price, increase size, or change TIF/cloid — the order is removed from its current position and re-queued at the back of the new price level. It loses its original queue priority.

If the new price would immediately cross the book and match against a resting opposite-side order, the modification request is rejected. Cancel the order and place a new one to execute at a marketable price.

Request Body

Locate by Order ID
Locate by Client Order ID

Use oid to identify the order by the exchange-assigned ID returned in resting.oid.

{
  "action": {
    "type": "modify",
    "a": 1,
    "oid": 12345,
    "p": "150",
    "s": "8",
    "tif": "Gtc"
  },
  "signature": { "r": "0x...", "s": "0x...", "v": 28 },
  "nonce": 1778858100000
}

Use cloid to find the order by its client-assigned ID, and optionally update the client order ID at the same time with c.

{
  "action": {
    "type": "modify",
    "a": 1,
    "cloid": "1778763737044",
    "p": "151",
    "c": "1778858200000"
  },
  "signature": { "r": "0x...", "s": "0x...", "v": 28 },
  "nonce": 1778858200100
}

Action Fields

string

required

Fixed value: "modify".

int32

required

asset — The integer contract ID of the order to modify.

int64

orderId — Exchange-assigned order ID from resting.oid. Takes priority over cloid when both are provided. At least one of oid or cloid must be present.

string

clientOrderId (locate) — Client order ID used to find the order when oid is not provided. Must match the c field set at placement.

string

price — New limit price as a decimal string. Omit to keep the existing price unchanged.

string

size — New total target size as a decimal string. This is the total quantity including any already-filled amount, not just the remaining leaves size. Omit to keep the existing size unchanged.

string

timeInForce — New time-in-force for the order. Only "Gtc" (good-til-cancel) or "Alo" (add-liquidity-only / post-only) are accepted. Omit to keep the existing TIF unchanged.

string

clientOrderId (update) — New client order ID to assign to the order after modification. Omit to keep the existing client order ID unchanged.

You must provide at least one of oid or cloid to identify the order. All other fields (p, s, tif, c) are optional — include only the fields you want to change.

Responses

Success
Rejected

The order was modified. The response reflects the new state of the order.

{
  "status": "ok",
  "response": {
    "type": "modify",
    "data": {
      "orderId": 12345,
      "limitPrice": 150,
      "totalSize": 8,
      "leavesSize": 5,
      "clientOrderId": 1778858200000
    }
  }
}

The modification was rejected. Check errorCode and errorMessage for the reason.

{
  "status": "ok",
  "response": {
    "type": "modify",
    "data": {
      "orderId": 0,
      "limitPrice": 0,
      "totalSize": 0,
      "leavesSize": 0,
      "clientOrderId": 0,
      "errorCode": 7,
      "errorMessage": "orderId not found"
    }
  }
}

Response Fields

int64

The unchanged exchange-assigned order ID of the modified order.

number

The new limit price after the modification is applied.

number

The new total size of the order (including already-filled quantity).

number

The remaining unfilled quantity still resting in the book after the modification.

number

The updated client order ID. Reflects the new value if c was provided, or the previous value if it was not.

int

Absent or 0 indicates success. Any non-zero value indicates a rejection; read errorMessage for details. On rejection, all numeric fields are 0.

string

Human-readable rejection reason. Only present when errorCode is non-zero.

Known Errors

errorMessage	Cause
`orderId not found`	The `oid` or `cloid` does not match any active order
`clOrdId not found`	Located by `cloid`, but no matching active order was found
`order already canceled`	The target order was already cancelled before this request arrived
`order not open`	The order is in a terminal state (fully filled or cancelled)
`new size must exceed already-filled amount`	The requested `s` is less than or equal to the quantity already filled
`modify supports resting TIF only (GTC / POST_ONLY)`	`tif` was set to `"Ioc"` or another non-resting value
`modified price is marketable (would cross the book); cancel and place a new order instead`	The new `p` would immediately match against a resting opposite-side order
`newClientOrderId already in use by an active order`	The `c` value collides with another active order’s client order ID
`insufficient margin for modified order`	Increasing `s` would require more margin than is available; the change is automatically rolled back

Overview

Account

Orders

Margin & Leverage

Conditional Orders

Collateral Transfers

Fee Settings

API Wallet

modify: Update an Open Order Price, Size, or TIF

Endpoint

Priority Rules

Request Body

Action Fields

Responses

Response Fields

Known Errors

​Endpoint

​Priority Rules

​Request Body

​Action Fields

​Responses

​Response Fields

​Known Errors

Endpoint

Priority Rules

Request Body

Action Fields

Responses

Response Fields

Known Errors