HTTP client AT commands

HTTP client connection #XHTTPCCON
HTTP request #XHTTPCREQ
HTTP response #XHTTPCRSP
- Unsolicited notification

The following commands list contains the HTTP client AT commands.

HTTP client connection #XHTTPCCON 

The #XHTTPCCON command allows you to connect to and disconnect from an HTTP server and to show the HTTP connection information.

Set command 

The set command allows you to connect to and disconnect from an HTTP server.

Syntax

AT#XHTTPCCON=<op>[,<host>,<port>[,<sec_tag>]]

The <op> parameter can accept one of the following values:
- 0 - Disconnect from the HTTP server.
- 1 - Connect to the HTTP server for IP protocol family version 4.
- 2 - Connect to the HTTP server for IP protocol family version 6.
The <host> parameter is a string. It represents the HTTP server hostname.
The <port> parameter is an unsigned 16-bit integer (0 - 65535). It represents the HTTP server port.
The <sec_tag> parameter is an integer. It indicates to the modem the credential of the security tag used for establishing a secure connection.

Response syntax

#XHTTPCCON=<state>

The <state> value can return one of the following:
- 0 - Disconnected
- 1 - Connected

Example

AT#XHTTPCCON=1,"postman-echo.com",80
#XHTTPCCON:1
OK

Read command 

The read command shows the HTTP connection information.

Syntax

AT#XHTTPCCON?

Response syntax

XHTTPCCON: <state>,<host>,<port>[,<sec_tag>]]

Example

AT#XHTTPCCON?
#XHTTPCCON: 1,"postman-echo.com",80
OK

Test command 

The test command tests the existence of the command and provides information about the type of its subparameters.

Example

AT#XHTTPCCON=?
#XHTTPCCON: (0,1),<host>,<port>,<sec_tag>
OK

HTTP request #XHTTPCREQ 

The #XHTTPCREQ command allows you to send an HTTP request to the server.

Set command 

The set command allows you to send an HTTP request to the server.

Syntax

AT#XHTTPCREQ=<method>,<resource>[,<headers>[,<content_type>,<content_length>[,<chunked_transfer>]]]

The <method> is a string. It represents the request method string.
The <resource> is a string. It represents the target resource to apply the request.
The <headers> parameter is a string. It represents the optional headers field of the request. Each header field should end with <CR><LF>. Any occurrence of “\r\n” (4 bytes) inside is replaced by <CR><LF> (2 bytes).

Note

Host, Content-Type and Content-Length must not be included.
The <content_type> is a string. It represents the HTTP/1.1 Content-Type of the payload.
The <content_length> is an integer. It represents the HTTP/1.1 Content-Length of the payload. This parameter is ignored if <chunked_transfer> is not 0.
The <chunked_transfer> is an integer. It indicates if the payload will be sent in chunked mode or not.
- 0 - normal mode (default)
- 1 - chunked mode
If <content_length> is greater than 0 or <chunked_transfer> is not 0, the SLM application enters slm_data_mode. The SLM sends the payload to the HTTP server until the terminator string defined in CONFIG_SLM_DATAMODE_TERMINATOR is received.

Response syntax

#XHTTPCREQ:<state>

The <state> value can return one of the following:

0 - Request sent successfully
1 - Wait for payload data
Negative integer - Error code

Example

The following example sends a GET request to retrieve data from the server without any optional header:

AT#XHTTPCCON=1,"postman-echo.com",80

#XHTTPCCON: 1

OK

AT#XHTTPCREQ="GET","/get?foo1=bar1&foo2=bar2"

OK

#XHTTPCREQ: 0

HTTP/1.1 200 OK
Date: Tue, 01 Mar 2022 05:22:27 GMT
Content-Type: application/json; charset=utf-8
Content-Length: 244
Connection: keep-alive
ETag: W/"f4-/OfnvALw5zFsaujZvrn62iBBcKo"
Vary: Accept-Encoding
set-cookie: sails.sid=s%3AzTRyDH581ybGp-7K1k78tkBmVLeybFTY.Z7c5iNEaK0hH5hIMsuJpuZEH18d%2FbtSqOuhRAh1GmYM; Path=/; HttpOnly


#XHTTPCRSP:337,1
{"args":{"foo1":"bar1","foo2":"bar2"},"headers":{"x-forwarded-proto":"http","x-forwarded-port":"80","host":"postman-echo.com","x-amzn-trace-id":"Root=1-621dad93-79bf415c46aa37f925498d97"},"url":"http://postman-echo.com/get?foo1=bar1&foo2=bar2"}
#XHTTPCRSP:244,1

The following example sends a POST request, with headers delimited by “\r\n”, and with a JSON payload:

AT#XHTTPCREQ="POST","/post","User-Agent: slm\r\naccept: */*\r\n","application/json",17

OK

#XHTTPCREQ: 1
{"hello":"world"}+++
#XHTTPCREQ: 0

#XDATAMODE: 0

HTTP/1.1 200 OK
Date: Tue, 01 Mar 2022 05:22:28 GMT
Content-Type: application/json; charset=utf-8
Content-Length: 359
Connection: keep-alive
ETag: W/"167-2YuosrP0ARLW1c5oeDiW7MId014"
Vary: Accept-Encoding
set-cookie: sails.sid=s%3A_b9-1rOslsmoczQUGjv93SicuBw8f6lb.x%2B6xkThAVld5%2FpykDn7trZ9JGh%2Fir3MVU0izYBfB0Kg; Path=/; HttpOnly


#XHTTPCRSP:342,1
{"args":{},"data":{"hello":"world"},"files":{},"form":{},"headers":{"x-forwarded-proto":"http","x-forwarded-port":"80","host":"postman-echo.com","x-amzn-trace-id":"Root=1-621dad94-2fcac1637dc28f172c6346e6","content-length":"17","user-agent":"slm","accept":"*/*","content-type":"application/json"},"json":{"hello":"world"},"url":"http://postman-echo.com/post"}
#XHTTPCRSP:359,1

Read command 

The read command is not supported.

Test command 

The test command is not supported.

HTTP response #XHTTPCRSP 

The #XHTTPCRSP is an unsolicited notification that indicates that a part of the HTTP response has been received.

Unsolicited notification 

It indicates that a part of the HTTP response has been received.

Syntax

#XHTTPCRSP=<byte_received>,<state><CR><LF><response>

The <byte_received> is an integer. It represents the length of a partially received HTTP response.
The <state> value can return one of the following:
- 0 - There is more HTTP response data to come.
- 1 - The entire HTTP response has been received.
The <response> is the raw data of the HTTP response, including headers and body.