# Send fixed number with cheap price

This endpoint is used to send the individually message to the recipient using the fixed number.

It is ideal to send the OTP (One-Time-Password) for use-case like verficiation for example.

## HTTP request

\ <mark style="color:yellow;">**`POST`**</mark> [https://rest.esms.vn/MainService.svc/json/SendMultipleMessage\_V4\_post\_json/](http://rest.esms.vn/MainService.svc/json/SendMultipleMessage_V4_post_json/)<br>

* **Content Type:** <mark style="color:orange;">application/json</mark>
* **Response Type:** <mark style="color:orange;">application/json</mark>

```json
curl --location 'https://rest.esms.vn/MainService.svc/json/SendMultipleMessage_V4_post_json/' \
--header 'Content-Type: application/json' \
--data '{
   "ApiKey": "{{ApiKey}}",
   "Content": "{{Content}}",
   "Phone": "{{Phone}}",
   "SecretKey": "{{SecretKey}}",
   "SmsType": "8",
   "IsUnicode": "{{IsUnicode}}",
   "Sandbox": "{{Sandbox}}",
   "campaignid": "{{campaignid}}",
   "RequestId": "{{RequestId}}",
   "CallbackUrl": "{{CallbackUrl}}",
   "SendDate":"{{SendDate}}"
}'
```

* **Request body**

<table><thead><tr><th width="145">Paramter</th><th width="121">Type</th><th width="147" data-type="checkbox">Required</th><th>Description</th></tr></thead><tbody><tr><td>ApiKey</td><td>string</td><td>true</td><td>Your API Key.</td></tr><tr><td>Content</td><td>string</td><td>true</td><td>The message content.</td></tr><tr><td>Phone</td><td>string</td><td>true</td><td>The phone number of receivers.</td></tr><tr><td>SecretKey</td><td>string</td><td>true</td><td>Your Secret Key.</td></tr><tr><td>SmsType</td><td>string</td><td>true</td><td>Message type<br>8: Fixed number</td></tr><tr><td>Unicode</td><td>string</td><td>false</td><td><p>Message charset value (<strong>default is 0</strong>):<br>1: Unicode.</p><p>0: Non-Unicode.</p></td></tr><tr><td>Sandbox</td><td>string</td><td>false</td><td>Sandbox option value (<strong>default is 0</strong>):<br>1: For testing purpose to verify the validation of the request. Message is not charged and sent to the receiver.<br>0: Message will be processed to the receiver properly.</td></tr><tr><td>campaignid</td><td>string</td><td>false</td><td>The campaign name of the request.</td></tr><tr><td>RequestId</td><td>string</td><td>false</td><td>Partner ID passed to block duplicates and check if needed.
<br>Maximum length 50 characters.
<br>Each RequestId passed is valid for blocking for 24 hours.</td></tr><tr><td>CallbackUrl</td><td>string</td><td>false</td><td>The webhook URL that will receive the status of message after it processed to the operator. It is used for determine whether the SMS is succcessfully delivered to the receiver or failed.<br>See the sample request at <a href="https://samplefordevelopers.esms.vn/#20f85e1f-3d9e-4ff4-bc4f-8d9c9edbc88a">here</a>.<br>More detail at <a href="/pages/HxTrJlnDLexPUwac9BWb">here</a>.</td></tr><tr><td>SendDate</td><td>string</td><td>false</td><td>Scheduler the message to the receiver.<br>If it's empty, the message will be instantly sent to the receiver.<br>Format: <strong>yyyy-mm-dd hh:MM:ss</strong></td></tr></tbody></table>

***

* **Response:**

{% tabs %}
{% tab title="100" %}

```json
{
    "CodeResult": "100",
    "CountRegenerate": 0,
    "SMSID": "d8e0f1f0702544b2acb456ca9ccfd111250"
}
```

**Valid request.**
{% endtab %}

{% tab title="101" %}

```json
{
    "CodeResult": "101",
    "CountRegenerate": 0,
    "ErrorMessage": "Authorize Failed"
}
```

**Invalid credential.**
{% endtab %}

{% tab title="99" %}

```
{
  "error": "Invalid request"
}
```

Connection is error. Contact the admin for reference.
{% endtab %}
{% endtabs %}

* **Response body**

| Parameter    | Type   | Description                                  |
| ------------ | ------ | -------------------------------------------- |
| CodeResult   | string | Response code.                               |
| SMSID        | string | The message id eSMS system.                  |
| ErrorMessage | string | The error message if the request is invalid. |

* *<mark style="color:yellow;">**The detail of error code can refer at**</mark>* [**Table of error codes**](/en/esms-api/table-of-error-codes.md) **.**
* *<mark style="color:yellow;">**Get the  sample of code for programing languagues to use in Postman refer at**</mark>* [**Link  of code samples**](https://samplefordevelopers.esms.vn/#850974b9-12cf-46f5-946c-e8e15aa3585b)**.**


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://developers.esms.vn/en/esms-api/send-sms-api/send-fixed-number-with-cheap-price.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.