void setup() { Ethernet.begin({0x90,0xA2,0xDA,0x00,0x55,0x8D}); } void loop() { if (client.connect("www.someapi.com",80)) { client.println("POST /api/v1/endpoints HTTP/1.1"); client.println("Host: www.someapi.com"); client.println("Content-Type: application/json"); client.print("Content-Length: "); client.println(data.length()); client.println(); client.print(data); client.println(); } } LOL