---
title: "Modify Order"
method: POST
path: "/v1/order/{orderId}/modify"
tags: ["Orders"]
---

# Modify Order

`POST /v1/order/{orderId}/modify`

Modify an existing order in the marketplace. Allows changing price, quantity, time in force, and other parameters.

## Path parameters

- `orderId` string, required

## Request body

- ModifyOrderRequest — Request to modify an existing order
  - `marketSlug` string — Unique market slug for the order being modified
  - `price` Amount — Represents a monetary amount with its currency
    - `value` string, decimal, required — The amount as a decimal string
    - `currency` string, required — The currency code
  - `quantity` number, double — Order quantity in contracts. Supports decimal quantities on markets whose minimumTradeQty is less than 1.
  - `tif` 'TIME_IN_FORCE_DAY' | 'TIME_IN_FORCE_GOOD_TILL_CANCEL' | 'TIME_IN_FORCE_IMMEDIATE_OR_CANCEL' | 'TIME_IN_FORCE_GOOD_TILL_TIME' | 'TIME_IN_FORCE_FILL_OR_KILL' — TimeInForce specifies how long the order remains in effect.
  - `participateDontInitiate` boolean — Order must rest on the book prior to matching (maker only)
  - `goodTillTime` string — Good till time for orders with TIME_IN_FORCE_GOOD_TILL_DATE

## Response `200`

Order modified successfully

- ModifyOrderResponse — Response for order modification (empty on success)

## Other responses

- `400` — Bad request - invalid order modification request
- `401` — Unauthorized - invalid or missing authentication token
- `500` — Internal server error

---

[API](https://skmtc.dev/polymarket/apis/portfolio-api.md) · [All operations](https://skmtc.dev/polymarket/apis/portfolio-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/polymarket/portfolio-api/revisions/150874842db1/schema)