> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chainstack.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Modify order | Hyperliquid exchange
> Modifies an existing order on the Hyperliquid exchange. You can change the price, size, and other parameters without canceling and replacing the order.
You can only use this endpoint on the official Hyperliquid public API. It is not available through Chainstack, as the open-source node implementation does not support it yet. See [Hyperliquid methods](/docs/hyperliquid-methods) for the full availability breakdown.
This endpoint requires signature authentication. See our comprehensive [Authentication via Signatures guide](/docs/hyperliquid-authentication-guide) for implementation details.
Modifies an existing order on the Hyperliquid exchange. You can change the price, size, and other parameters without canceling and replacing the order.
## Parameters
### Required parameters
* `action` (object, required) — The modify action object containing:
* `type` (string) — Must be `"modify"`
* `oid` (number or string) — Order ID to modify, or cloid if using client order ID
* `order` (object) — New order parameters:
* `a` (number) — Asset index
* `b` (boolean) — Is buy order (true for buy/long, false for sell/short)
* `p` (string) — New limit price
* `s` (string) — New size in units of the base asset
* `r` (boolean) — Reduce only order
* `t` (object) — Order type specification:
* For limit orders: `{"limit": {"tif": "Alo" | "Ioc" | "Gtc"}}`
* For trigger orders: `{"trigger": {"isMarket": boolean, "triggerPx": string, "tpsl": "tp" | "sl"}}`
* `c` (string, optional) — New client order ID (128-bit hex string)
* `nonce` (number, required) — Current timestamp in milliseconds (must be recent)
* `signature` (object, required) — EIP-712 signature of the action
### Optional parameters
* `vaultAddress` (string, optional) — Address when trading on behalf of a vault or subaccount
* `expiresAfter` (number, optional) — Timestamp in milliseconds after which the request is rejected
## Returns
Returns an object with modification status:
* `status` — `"ok"` if request processed
* `response` — Contains modification details:
* `type` — `"modify"`
* `data` — Modification result information
## Example request
```shell cURL theme={"system"}
curl -X POST https://api.hyperliquid.xyz/exchange \
-H "Content-Type: application/json" \
-d '{
"action": {
"type": "modify",
"oid": 77738308,
"order": {
"a": 0,
"b": true,
"p": "51000",
"s": "0.02",
"r": false,
"t": {"limit": {"tif": "Gtc"}}
}
},
"nonce": 1234567890123,
"signature": {...}
}'
```
```python Python (hyperliquid-python-sdk) theme={"system"}
from hyperliquid.exchange import Exchange
from hyperliquid.utils import constants
import eth_account
# Initialize with your private key
account = eth_account.Account.from_key("0x...")
exchange = Exchange(account, constants.MAINNET_API_URL)
# Modify an existing order
modify_result = exchange.modify_order(
oid=77738308,
name="BTC",
is_buy=True,
sz=0.02,
limit_px=51000,
order_type={"limit": {"tif": "Gtc"}},
reduce_only=False,
)
print(modify_result)
```
```typescript TypeScript (@nktkas/hyperliquid) theme={"system"}
import { ExchangeClient, HttpTransport } from "@nktkas/hyperliquid";
import { privateKeyToAccount } from "viem/accounts";
// Initialize with your private key
const wallet = privateKeyToAccount("0x..."); // viem or ethers
const transport = new HttpTransport(); // public Hyperliquid API
const exchange = new ExchangeClient({ transport, wallet });
// Modify an existing order
const modifyResult = await exchange.modify({
oid: 77738308,
order: {
a: 0,
b: true,
p: "51000",
s: "0.02",
r: false,
t: { limit: { tif: "Gtc" } },
},
});
console.log(modifyResult);
```
## Modification behavior
* **Priority preservation** — Modifying only the size preserves queue priority
* **Price changes** — Changing the price moves the order to the back of the queue
* **Partial fills** — Can modify partially filled orders (remaining size only)
* **Order types** — Can change between different order types
## Use cases
* **Price adjustment** — Update limit price based on market movements
* **Size scaling** — Increase or decrease order size
* **Strategy updates** — Adjust orders without losing position in queue
* **Risk management** — Convert orders to reduce-only
Modifying an order is more efficient than cancel-and-replace, especially when only changing the size, as it can preserve your position in the order queue.
Some modifications may cause loss of queue priority. Price changes always move the order to the back of the queue at the new price level.
## OpenAPI
````yaml openapi/hyperliquid_node_api/hypercore_exchange/exchange_modify_order.json post /exchange
openapi: 3.0.0
info:
title: Hyperliquid Exchange API
version: 1.0.0
description: >-
API for trading operations on Hyperliquid exchange requiring authentication.
⚠️ WARNING: These endpoints require EIP-712 signatures for authentication.
The example values provided will NOT work without proper cryptographic
signing. You must implement EIP-712 signing to use these endpoints
successfully.
servers:
- url: https://api.hyperliquid.xyz
security: []
paths:
/exchange:
post:
tags:
- hyperliquid exchange
summary: Modify order
operationId: modifyOrder
requestBody:
required: true
content:
application/json:
schema:
type: object
properties:
action:
type: object
properties:
type:
type: string
default: modify
enum:
- modify
description: Action type for modifying orders
oid:
type: integer
description: Order ID to modify
order:
type: object
description: New order parameters
properties:
a:
type: integer
description: >-
Asset index (use universe index for perps, 10000 +
index for spot)
b:
type: boolean
description: >-
Is buy order (true for buy/long, false for
sell/short)
p:
type: string
description: Limit price (use '0' for market orders)
s:
type: string
description: Size in units of the base asset
r:
type: boolean
description: Reduce only order
t:
type: object
description: Order type specification
oneOf:
- type: object
properties:
limit:
type: object
properties:
tif:
type: string
enum:
- Alo
- Ioc
- Gtc
description: >-
Time in force: Alo (add liquidity only),
Ioc (immediate or cancel), Gtc (good til
canceled)
required:
- tif
- type: object
properties:
trigger:
type: object
properties:
isMarket:
type: boolean
description: >-
Whether to place market order when
triggered
triggerPx:
type: string
description: Price at which to trigger the order
tpsl:
type: string
enum:
- tp
- sl
description: Take profit (tp) or stop loss (sl)
required:
- isMarket
- triggerPx
- tpsl
c:
type: string
description: Client order ID (128-bit hex string, optional)
required:
- a
- b
- p
- s
- r
- t
required:
- type
- oid
- order
nonce:
type: integer
description: Current timestamp in milliseconds
signature:
type: object
description: EIP-712 signature of the action with r, s, v components
properties:
r:
type: string
description: ECDSA signature r component (hex string)
example: >-
0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef
s:
type: string
description: ECDSA signature s component (hex string)
example: >-
0xfedcba0987654321fedcba0987654321fedcba0987654321fedcba0987654321
v:
type: integer
description: ECDSA recovery id (27 or 28)
example: 27
required:
- r
- s
- v
vaultAddress:
type: string
description: >-
Address when trading on behalf of a vault or subaccount
(optional)
nullable: true
expiresAfter:
type: integer
description: >-
Timestamp in milliseconds after which the request is
rejected (optional)
required:
- action
- nonce
- signature
example:
action:
type: modify
oid: 123456789
order:
a: 0
b: true
p: '27.5'
s: '1.0'
r: false
t:
limit:
tif: Gtc
c: '0x1234567890abcdef1234567890abcdef'
nonce: 1705234567890
signature:
r: >-
0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef
s: >-
0xfedcba0987654321fedcba0987654321fedcba0987654321fedcba0987654321
v: 27
vaultAddress: null
responses:
'200':
description: Order modification result
content:
application/json:
schema:
type: object
properties:
status:
type: string
description: Request status
response:
type: object
properties:
type:
type: string
data:
type: object
properties:
statuses:
type: array
items:
oneOf:
- type: object
properties:
resting:
type: object
properties:
oid:
type: integer
description: Order ID
- type: object
properties:
filled:
type: object
properties:
totalSz:
type: string
description: Total size filled
avgPx:
type: string
description: Average fill price
oid:
type: integer
description: Order ID
- type: object
properties:
error:
type: string
description: Error message
example:
status: ok
response:
type: modify
data:
statuses:
- resting:
oid: 77738309
````