post '/user', provides: :json do params = JSON.parse request.body.read puts params['name'] puts params['age'] end $ curl -v -H "Accept: application/json" -H "Content-type: application/json" -X POST -d '{"name":"hogehoge","age":"30"}' http://localhost:9292/user -w "\n%{http_code}\n" public interface ApiService { @Headers({ "Accept: application/json", "Content-type: application/json" }) @POST("/user
![RetrofitでJSONをPOSTする - Qiita](https://cdn-ak-scissors.b.st-hatena.com/image/square/d8862e87d7f146ccc280118ddfbbfc2db65191fa/height=288;version=1;width=512/https%3A%2F%2Fqiita-user-contents.imgix.net%2Fhttps%253A%252F%252Fcdn.qiita.com%252Fassets%252Fpublic%252Farticle-ogp-background-412672c5f0600ab9a64263b751f1bc81.png%3Fixlib%3Drb-4.0.0%26w%3D1200%26mark64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTk3MiZoPTM3OCZ0eHQ9UmV0cm9maXQlRTMlODElQTdKU09OJUUzJTgyJTkyUE9TVCVFMyU4MSU5OSVFMyU4MiU4QiZ0eHQtYWxpZ249bGVmdCUyQ3RvcCZ0eHQtY29sb3I9JTIzMjEyMTIxJnR4dC1mb250PUhpcmFnaW5vJTIwU2FucyUyMFc2JnR4dC1zaXplPTU2JnM9YTQxNzgxNTkyY2Y0YThjZWEyOGJhYjQwYzkzM2E0MWE%26mark-x%3D142%26mark-y%3D57%26blend64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZoPTc2Jnc9NzcwJnR4dD0lNDBzaHRzJnR4dC1jb2xvcj0lMjMyMTIxMjEmdHh0LWZvbnQ9SGlyYWdpbm8lMjBTYW5zJTIwVzYmdHh0LXNpemU9MzYmdHh0LWFsaWduPWxlZnQlMkN0b3Amcz0wMjcxMTRiZTQ3ZmJkYjJjNTVmOWVjNmZhNzY3MzViMg%26blend-x%3D142%26blend-y%3D486%26blend-mode%3Dnormal%26s%3D73790025e3db0cc164d369f5e45e3323)