Velstack

Topup API

The Topup API provides all the tools you need to efficiently manage topup and account balance data within your communication system. Whether you're handling one-off transactions The Topup API ensures you can securely store, retrieve, and update topup information with ease.

To ensure a successful sms topup, you must ensure you have enough balance on your integration Topup Here.

SMS Unit Topup

Topup your account balance with the SMS Unit Topup endpoint. This endpoint allows you to add SMS units to your account, ensuring you have sufficient credits to send messages to your contacts. Whether you're running a campaign or need to maintain a steady flow of communication, this API makes it easy to manage your SMS credits effectively.

Headers

  • Name
    Authorization
    Type
    string
    Description
    Set value to Bearer SECRET_KEY
  • Name
    Content-Type
    Type
    string
    Description
    Set value to application/json

Request Body

  • Name
    type
    Type
    string
    Description
    Type of topup. Allow values are expiry and non_expiry
  • Name
    amount
    Type
    float
    Description
    Amount to topup. Min amount is 10.0

Request

POST
/v1/sms/topup
<span><span style="color: var(--shiki-color-text)">curl -X POST https://api.velstack.com/v1/sms/topup \</span></span>
<span><span style="color: var(--shiki-color-text)">    -H </span><span style="color: var(--shiki-token-string-expression)">&quot;Authorization: Bearer SECRET_KEY&quot;</span><span style="color: var(--shiki-color-text)"> \</span></span>
<span><span style="color: var(--shiki-color-text)">    -H </span><span style="color: var(--shiki-token-string-expression)">&quot;Content-Type: application/json&quot;</span><span style="color: var(--shiki-color-text)"> \</span></span>
<span><span style="color: var(--shiki-color-text)">    -d </span><span style="color: var(--shiki-token-string-expression)">&#39;{</span></span>
<span><span style="color: var(--shiki-token-string-expression)">        &quot;type&quot;: &quot;expiry&quot;,</span></span>
<span><span style="color: var(--shiki-token-string-expression)">        &quot;amount&quot;: 10.0</span></span>
<span><span style="color: var(--shiki-token-string-expression)">    }&#39;</span></span>
<span></span>
<span><span style="color: var(--shiki-color-text)">{</span></span>
<span><span style="color: var(--shiki-color-text)">    </span><span style="color: var(--shiki-token-keyword)">&quot;status&quot;</span><span style="color: var(--shiki-token-punctuation)">:</span><span style="color: var(--shiki-color-text)"> </span><span style="color: var(--shiki-token-constant)">true</span><span style="color: var(--shiki-token-punctuation)">,</span></span>
<span><span style="color: var(--shiki-color-text)">    </span><span style="color: var(--shiki-token-keyword)">&quot;message&quot;</span><span style="color: var(--shiki-token-punctuation)">:</span><span style="color: var(--shiki-color-text)"> </span><span style="color: var(--shiki-token-string-expression)">&quot;Top Up successful&quot;</span><span style="color: var(--shiki-token-punctuation)">,</span></span>
<span><span style="color: var(--shiki-color-text)">    </span><span style="color: var(--shiki-token-keyword)">&quot;data&quot;</span><span style="color: var(--shiki-token-punctuation)">:</span><span style="color: var(--shiki-color-text)"> {</span></span>
<span><span style="color: var(--shiki-color-text)">        </span><span style="color: var(--shiki-token-keyword)">&quot;id&quot;</span><span style="color: var(--shiki-token-punctuation)">:</span><span style="color: var(--shiki-color-text)"> </span><span style="color: var(--shiki-token-constant)">92</span><span style="color: var(--shiki-token-punctuation)">,</span></span>
<span><span style="color: var(--shiki-color-text)">        </span><span style="color: var(--shiki-token-keyword)">&quot;type&quot;</span><span style="color: var(--shiki-token-punctuation)">:</span><span style="color: var(--shiki-color-text)"> </span><span style="color: var(--shiki-token-string-expression)">&quot;expiry&quot;</span><span style="color: var(--shiki-token-punctuation)">,</span></span>
<span><span style="color: var(--shiki-color-text)">        </span><span style="color: var(--shiki-token-keyword)">&quot;units&quot;</span><span style="color: var(--shiki-token-punctuation)">:</span><span style="color: var(--shiki-color-text)"> </span><span style="color: var(--shiki-token-constant)">400</span><span style="color: var(--shiki-token-punctuation)">,</span></span>
<span><span style="color: var(--shiki-color-text)">        </span><span style="color: var(--shiki-token-keyword)">&quot;balance&quot;</span><span style="color: var(--shiki-token-punctuation)">:</span><span style="color: var(--shiki-color-text)"> </span><span style="color: var(--shiki-token-constant)">400</span><span style="color: var(--shiki-token-punctuation)">,</span></span>
<span><span style="color: var(--shiki-color-text)">        </span><span style="color: var(--shiki-token-keyword)">&quot;expires_at&quot;</span><span style="color: var(--shiki-token-punctuation)">:</span><span style="color: var(--shiki-color-text)"> </span><span style="color: var(--shiki-token-string-expression)">&quot;2026-05-21T20:54:03.200414Z&quot;</span><span style="color: var(--shiki-token-punctuation)">,</span></span>
<span><span style="color: var(--shiki-color-text)">        </span><span style="color: var(--shiki-token-keyword)">&quot;created_at&quot;</span><span style="color: var(--shiki-token-punctuation)">:</span><span style="color: var(--shiki-color-text)"> </span><span style="color: var(--shiki-token-string-expression)">&quot;2026-04-21T20:54:03.000000Z&quot;</span></span>
<span><span style="color: var(--shiki-color-text)">    }</span></span>
<span><span style="color: var(--shiki-color-text)">}</span></span>
<span></span>