This gist lists only the basic commands to test REST APIs with curl. If you need something more advanced, this book has everything you may need.
Display the response only
curl http://www.example.com/api/ping
Display the headers as well
curl -v http://www.example.com/api/ping
Save the response to a file
curl -o user_3.json http://www.example.com/api/users/3
Use -d to set data, -X to mention method
Send form data (default) application/x-www-form-urlencoded with POST
curl -d 'name=Sugar&category_id=3' http://example.com/api/products
curl -X PUT -d 'name=Sugar&category_id=3' http://example.com/api/products
Field values can be mentioned separately.
curl -d name=Sugar -d category_id=3 http://example.com/api/products
Submit as JSON Request Body
curl -d '{"name":"Sugar", "category_id":3}' -H 'Content-Type: application/json' http://example.com/api/products
curl -X PUT -d '{"name":"Sugar", "category_id":3}' -H 'Content-Type: application/json' http://example.com/api/products
For windows command prompt, you'd need to replace the single quotes with double quotes and need to escape as \" where necessary.
curl -d "{\"name\":\"Sugar\", \"category_id\":3}" ...
Set Request body from a file
curl -d @path/to/data.json -H 'Content-Type: application/json' http://example.com/api/products
curl -X PUT -d @path/to/data.json -H 'Content-Type: application/json' http://example.com/api/products
DELETE Request
curl -X DELETE http://example.com/api/products/9
Use --header or -H option
curl -H 'Accept: application/json' -H 'X-Api-Key: 842be059-5e0b-43c1-bd95-5c7705858b0b' http://example.com/api/resource
Basic Auth
curl --user username:password http://example.com/api/resource
Access Token
curl -H "Authorization: Bearer b1094abc0-54a4-3eab-7213-877142c33fh3" http://example.com/api/resource
API Key
curl -H 'X-Api-Key: 842be059-5e0b-43c1-bd95-5c7705858b0b' http://example.com/api/resource
curl -X PUT --data-urlencode "name=John Doe (Junior)" -d category_id=3 http://example.com/api/users/13
File contents can be urlencoded too
curl --data-urlencode [email protected] http://example.com/api/users
Use -F to submit as multipart/form-data
curl -F 'img_avatar=@/home/petehouston/hello.png' -F default=no http://example.com/api/users/13/avatar
Multiple files
curl -F 'id_page_1=@/path/to/front_side.jpg' -F 'id_page_2=@/path/to/back_side.jpg' http://example.com/api/users/13/photo_id
Array of files
curl -F 'pages[]=@/path/to/page_1.jpg' -F 'pages[]=@/path/to/page_2.jpg' ... http://example.com/api/books/9/pages
A nice little cheatsheet for when I (inevitably) forget params / arguments. Cheers!!