# Overview of the HTTP API features A variety of messaging and SMS features are supported by the gateway, which can be activated by including additional parameters. These parameters include the ones as shown in the table below. | Feature | Description | Values | Default | Parameter | | ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------- | ------------------------------------------- | -------------------- | | **Binary** | Force the message content to be sent as binary (8-bit) data. | 0,1 | 0 | *binary* | | **Client Message ID** | Client message ID defined by the user for message tracking. | 2993b6b548 | none | *cliMsgId* | | **Concatenation** | Specifies the maximum number of message parts available for the message. | 1,2,3 | Defaults to setting on your API connection. | *concat* | | **Delivery Time** | Delays delivery of your SMS to the mobile device in minutes relative to the time at which the SMS was received by our gateway. | 10 | 0 | *deliv\_time* | | **Delivery Queue** | Delivers the message through one of three queues assigned to each client account. Messages in the highest priority queue will be delivered first. | 1,2,3 | 3 | *queue* | | **Destination Address** | The mobile number of the handset to which the message must be delivered (MSISDN). The number must be in international format with no leading zeros or ‘+’ symbol. | 27831234567 (South Africa) 16501234567 (USA) 44123456789 (UK) | none | *to* | | **Enable Callback** | Enables you to receive message delivery status updates via an HTTP request made to your server. | 0,1,2,3,4,5,6,7 | 0 | *callback* | | **Gateway Escalation** | Prompts an escalation to an alternative (more expensive) route, if messages are queued or delayed on the least-cost route. | 0,1 | 0 | *escalate* | | **Maximum Credits** | Overrides the maximum charge specified online in “routing profiles”. | 0.8,1,1.5,2,2.5,3 | none | *max\_credits* | | **Message Text** | The content of your SMS message. | Hello World | | *text* | | **Mobile Originated** | This is only applicable to clients that have subscribed to a two-way messaging service. We route via pre-defined carriers to enable the ability for a reply to be received. | 0,1 | 0 | *mo* | | **Required Features** | Some parameters and features are not set as “required” by default and may be dropped if the least-cost route does not support them. Set this parameter to ensure that the features set when an SMS is sent are supported by the gateway used. | Refer to description. | none | *req\_feat* | | **Scheduled Time** | Specify when a message should get delivered in GMT+0. | 2015-06-30T14:00:00Z | none | *scheduled\_time* | | **Sender ID** | The source/sender address that the message will appear to come from (also known as the “Sender ID”). These must be registered within your online account and approved by us before they may be used. Two-way numbers rented from us do not require approval. | | none | *from* | | **Unicode Message** | Two-digit language code. Convert your text to Unicode \[UCS-2 encoding]. See [http://www.Unicode.org/](http://www.unicode.org/). | 0,1 | 0 | *unicode* | | **User Data Header** | Set the UDH content of a message. | | | *udh* | | **Validity Period** | The validity period in minutes relative to the time at which the SMS was received by our gateway. The message will not be delivered if it is still queued on our gateway after this time period. | 25 | 24 Hours | *validity* | | **Bypass DNC Check** | Feature to bypass the DNC lookup. Default behavior is to do a lookup unless overridden by this parameter. A value of “0” will still force a lookup; a value of “1” will force a lookup bypass. | 0,1 | none | *bypass\_dnc\_check* | --- # 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://help.clickatell.com/developers-api-reference/developers-archive/sms-http-s-api/overview-of-the-http-api-features.md?ask= ``` 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.