HTTP client AT commands

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>

  • <state> is 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>

<state> is 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

<response><CR><LF>#XHTTPCRSP:<received_byte_count>,<state>

  • <response> is the raw data of the HTTP response, including headers and body.

  • <received_byte_count> is an integer. It represents the length of a partially received HTTP response.

  • <state> is one of the following:

    • 0 - There is more HTTP response data to come.

    • 1 - The entire HTTP response has been received.