I've just spent the best part of two hours with Windows and CURL, and, FINALLY had some success.   However, I'm not going to be able to EXACTLY answer your question, but wanted to help you on the way:   curl --get -H "Content-Type: application/json" -H "Accept: application/json" -H "X-Cisco-Meraki-API-Key: 65656565656565656565" https://api.meraki.com/api/v1/organizations   Is a simple "Get Orgs" API call   The issue I see with your code is that Windows is painfully picky with escaping double quotes and stuff. I visibly grew old trying to get it to work, and gave up.   What I did achieve, however, was to put the body into a file called body.json on my desktop. Nothing is escaped in here, other than the JSON I'm included        And to simplify things, I then issued the following command:   curl https://api.meraki.com/api/v1/networks/N_56565656565656565/webhooks/payloadTemplates --header "Content-Type: application/json" --header "Accept: application/json" --header "X-Cisco-Meraki-API-Key: 5656565656565656" --data "@C:\Users\Meraki Admin\Desktop\body.json"   MUCH easier. If you literally replicated EVERYTHING above and placed:   {"name":"Test Object","category":"network","type":"cidr","cidr":"ip4 address","groupIds":"[]"}    into the body.json you should have some success ... View more