> For the complete documentation index, see [llms.txt](https://docs.outpoll.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.outpoll.com/api/rest-api/private-endpoints/orders/place-market-order.md).

# Place Market Order

Execute an order at the best available price

`POST`

### Overview

Executes an order immediately at the best available price.

Use `am` for `BUY` orders and `q` for `SELL` orders.

### Authentication

HMAC-SHA256 authentication required.

| Header                  | Description                             |
| ----------------------- | --------------------------------------- |
| `OUTPOLL-API-KEY`       | Your API key                            |
| `OUTPOLL-API-SIGNATURE` | Base64URL-encoded HMAC-SHA256 signature |
| `OUTPOLL-API-TIMESTAMP` | Current Unix timestamp in seconds       |

Generate the signature from `timestamp + method + path + body`.

Timestamps must be within `30` seconds of server time.

### Common errors

| Code | Description                                           |
| ---- | ----------------------------------------------------- |
| 200  | OK — Request succeeded                                |
| 201  | Created — Resource created successfully               |
| 202  | Accepted — Request accepted for async processing      |
| 204  | No Content — Success with no response body            |
| 400  | Bad Request — Invalid parameters                      |
| 401  | Unauthorized — Missing or invalid API key / signature |
| 403  | Forbidden — API key permanently blocked               |
| 404  | Not Found — Resource does not exist                   |
| 429  | Too Many Requests — Rate limit exceeded               |
| 500  | Internal Server Error                                 |

### Request

* Method: `POST`
* Path: `/orders/market`

#### Request body

| Field | Type   | Required    | Description                                     |
| ----- | ------ | ----------- | ----------------------------------------------- |
| e     | string | Yes         | Event ID                                        |
| o     | string | Yes         | Outcome ID                                      |
| ba    | string | Yes         | Betting asset ID                                |
| qa    | string | Yes         | Quote asset ID                                  |
| s     | string | Yes         | Side: `BUY` or `SELL`                           |
| am    | number | Conditional | Amount in USDC to spend. Required for `BUY`     |
| q     | number | Conditional | Quantity in shares to sell. Required for `SELL` |

### Response

**Response** `200 OK` or `202 Accepted`

```json
{
  "i": "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
}
```

| Field | Type   | Description |
| ----- | ------ | ----------- |
| i     | string | Order ID    |


---

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