mongoose/docs/c-api/http.h/mg_connect_http.md

title	decl_name	symbol_kind	signature
mg_connect_http()	mg_connect_http	func	struct mg_connection *mg_connect_http(struct mg_mgr *mgr, mg_event_handler_t event_handler, const char *url, const char *extra_headers, const char *post_data);

Helper function that creates outbound HTTP connection.

url is a URL to fetch. It must be properly URL-encoded, e.g. have no spaces, etc. By default, mg_connect_http() sends Connection and Host headers. extra_headers is an extra HTTP headers to send, e.g. "User-Agent: my-app\r\n". If post_data is NULL, then GET request is created. Otherwise, POST request is created with the specified POST data. Note that if the data being posted is a form submission, the Content-Type header should be set accordingly (see example below).

Examples:

  nc1 = mg_connect_http(mgr, ev_handler_1, "http://www.google.com", NULL,
                        NULL);
  nc2 = mg_connect_http(mgr, ev_handler_1, "https://github.com", NULL, NULL);
  nc3 = mg_connect_http(
      mgr, ev_handler_1, "my_server:8000/form_submit/",
      "Content-Type: application/x-www-form-urlencoded\r\n",
      "var_1=value_1&var_2=value_2");