# Replace Limit Order

Atomically creates a replacement order and cancels the referenced open order. The replacement receives a new `limitOrderId`.

**Endpoint:** `POST /api/v1/limit-orders/limit/{limitOrderId}/replace`\
**Auth:** Required (`Authorization: Bearer YOUR_API_KEY`)

## Headers

| Header            | Type   | Required | Description                                                                                                                   |
| ----------------- | ------ | -------- | ----------------------------------------------------------------------------------------------------------------------------- |
| `Idempotency-Key` | string | Yes      | Required opaque dedupe token. Use UUIDv4 or ULID. Allowed characters: `A-Z`, `a-z`, `0-9`, `.`, `_`, `:`, `-`. Max 200 chars. |

## Path parameters

| Parameter      | Type   | Required | Description                    | Example      |
| -------------- | ------ | -------- | ------------------------------ | ------------ |
| `limitOrderId` | string | Yes      | Existing open order to replace | `lim_abc123` |

## Request body

Request shape matches `POST /api/v1/limit-orders/limit`.

| Field           | Type    | Required | Description                       | Example         |
| --------------- | ------- | -------- | --------------------------------- | --------------- |
| `fromChain`     | string  | Yes      | Source chain identifier           | `"arbitrum"`    |
| `toChain`       | string  | Yes      | Destination chain identifier      | `"avax"`        |
| `tokenIn`       | string  | Yes      | Input token identifier            | `"TBTC"`        |
| `tokenOut`      | string  | Yes      | Output token identifier           | `"WETH"`        |
| `amount`        | string  | Yes      | Human amount string               | `"100.00"`      |
| `minAmountOut`  | string  | Yes      | Minimum output amount             | `"1"`           |
| `timeInForce`   | string  | No       | `GTC`, `GTD`, `IOC`, or `FOK`     | `"GTC"`         |
| `expiresAtMs`   | integer | No       | Absolute expiry in ms since epoch | `1745407200000` |
| `expireAfterMs` | integer | No       | Relative expiry in ms             | `86400000`      |
| `network`       | string  | No       | `mainnet` or `testnet`            | `"mainnet"`     |
| `slippageBps`   | integer | No       | Quote-time slippage hint          | `75`            |
| `recipient`     | string  | No       | Recipient address                 | `"0x1234..."`   |

## Example

{% tabs %}
{% tab title="cURL" %}

```bash
curl -X POST 'https://api.gateway.zert.com/api/v1/limit-orders/limit/lim_abc123/replace' \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Idempotency-Key: limit-replace-001' \
  -d '{
    "timeInForce": "GTC",
    "minAmountOut": "2",
    "fromChain": "arbitrum",
    "toChain": "avax",
    "tokenIn": "TBTC",
    "tokenOut": "WETH",
    "network": "mainnet",
    "amount": "100.00",
    "slippageBps": 75,
    "recipient": "0x1234567890123456789012345678901234567890"
  }'
```

{% endtab %}

{% tab title="Example Response" %}

```json
{
  "data": {
    "limitOrderId": "lim_replacement_456",
    "status": "open",
    "expiresAtMs": 1745407200000,
    "minAmountOut": "2",
    "replacesLimitOrderId": "lim_abc123"
  },
  "meta": {
    "requestId": "req_xyz",
    "timestamp": "2026-04-23T12:00:00.000Z"
  }
}
```

{% endtab %}
{% endtabs %}

## Responses

| Code | Description                                   |
| ---- | --------------------------------------------- |
| 200  | Replaced                                      |
| 400  | Invalid request                               |
| 401  | Unauthorized                                  |
| 403  | Forbidden                                     |
| 404  | Not found                                     |
| 409  | Order not replaceable or idempotency conflict |
| 503  | PG unavailable                                |

{% embed url="<https://api.gateway.zert.com/docs>" %}
Zert API — Replace Limit Order
{% endembed %}


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