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

# How-to: Cancel and modify orders

> Cancel a single resting order, cancel all orders in an auction, or change an order's fee limit before the auction clears.

Match provides three mutation endpoints for resting orders: cancel a single
order, cancel all of your orders in the current auction, or modify an order's
fee limit. These operations are available at any time during an auction cycle
with one exception: the lock window that opens before clearing imposes
additional constraints.

<Warning>
  During the lock window, cancellations are blocked and only fee changes that
  make an order more competitive are accepted. Attempting to cancel returns
  error 136001. Attempting to make a fee less competitive returns error 137005.
  New orders are still accepted during the lock window. For a full explanation
  of the lock window and auction lifecycle, see [How Match
  works](/circle-match/concepts/how-it-works).
</Warning>

## Prerequisites

Before you begin, ensure that you've:

* Obtained a Circle API key with Match access
* Placed at least one order that is in `pending` status (see
  [Place and manage orders](/circle-match/howtos/place-orders))
* Retrieved the `auctionId` and `orderId` for the order you want to act on

## Steps

### Step 1. Cancel a single order

Send a `POST` request to `/v1/match/orders/cancel` with the `auctionId` and
`orderId` of the resting order.

```bash theme={null}
curl -X POST https://api-sandbox.circle.com/v1/match/orders/cancel \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "auctionId": 42,
    "orderId": "550e8400-e29b-41d4-a716-446655440000"
  }'
```

A successful response returns status `cancelled`:

```json theme={null}
{
  "data": {
    "auctionId": 42,
    "orderId": "550e8400-e29b-41d4-a716-446655440000",
    "status": "cancelled"
  }
}
```

If the lock window is open, the request is rejected with error 136001. Wait for
the auction to clear and retry against the next auction cycle if the order rolls
over.

### Step 2. Cancel all orders

To cancel every resting order you have in the current auction, send a `POST`
request to `/v1/match/orders/cancel-all`. No request body is required.

```bash theme={null}
curl -X POST https://api-sandbox.circle.com/v1/match/orders/cancel-all \
  -H "Authorization: Bearer $API_KEY"
```

A successful response lists all cancelled order IDs:

```json theme={null}
{
  "data": {
    "auctionId": 42,
    "orderIds": [
      "550e8400-e29b-41d4-a716-446655440000",
      "661f9511-f30c-52e5-b827-557766551111"
    ],
    "status": "cancelled"
  }
}
```

If you have no resting orders in the current auction, `orderIds` is an empty
array and the call still returns 200. As with single-order cancellation, this
endpoint returns error 136001 when the lock window is open.

### Step 3. Modify an order's fee

Use `POST /v1/match/orders/modify` to change the fee limit on a resting order.
Only the fee changes; the order remains in `pending` status with its original
size and side.

The competitiveness direction differs by order type:

* **BURN orders:** a higher `feeBps` is more competitive (willing to pay a
  larger fee)
* **MINT orders:** a lower `feeBps` is more competitive (requiring a smaller
  rebate)

Outside the lock window, you can move the fee in either direction. During the
lock window, the new `feeBps` must be more competitive than the current value.
Submitting a less competitive fee during the lock window returns error 137005.

To convert a limit order to a market order, set `feeBps` to `null`.

```bash theme={null}
curl -X POST https://api-sandbox.circle.com/v1/match/orders/modify \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "auctionId": 42,
    "orderId": "550e8400-e29b-41d4-a716-446655440000",
    "feeBps": "3"
  }'
```

A successful response confirms the order is still `pending` with the updated
fee:

```json theme={null}
{
  "data": {
    "auctionId": 42,
    "orderId": "550e8400-e29b-41d4-a716-446655440000",
    "status": "pending"
  }
}
```

## Error reference

| Code   | HTTP | Meaning                                                                                                                        |
| ------ | ---- | ------------------------------------------------------------------------------------------------------------------------------ |
| 136001 | 400  | The auction is locked. Cancellations are not accepted until the auction clears.                                                |
| 136002 | 400  | The auction is settling the previous batch. Try again after settlement completes.                                              |
| 137005 | 400  | During the lock window, a fee change must improve competitiveness. The submitted fee is less competitive than the current fee. |