Invalid Api key using RestServer
i faced the same issue .don't mention put/get/post in URL ,RestServer itself recognizes the request nature base on parameter you pass two step required to solve your problem .
1st Step :
http://localhost/projects/myapi/key/index_put.php
must change to :
http://localhost/projects/myapi/key/index.php
2nd step:
create an api kay using sha1(max 40 character) in the keys table (table structure show in config/rest.php file),enter 1 in is_private_key field and ::1 in ip_address field.create the record ,and check it again .
This question is old but for those who finds this, the answer is:
The library https://github.com/chriskacerguis/codeigniter-restserver when using PUT method, the API KEY should be in the put header variables as x-www-form-urlencoded type.
Use google chrome postman and fill like image below: