MGS9012: method not allowed

The server answered 405 method not allowed because the route does not serve the request's HTTP method. The Allow header names the methods it does serve.

[MGS9012] DELETE /api/v1/insight is not served; use GET
  see: .../MGS9012.md

Why

Each /api/v1/ route reads or writes one way: the read routes answer GET, and the few that change state (starting a share, disposing an attention request) take POST. A route never guesses what another method meant.

Resolution

Send the request with a method the Allow header names. A browser OPTIONS preflight is not refused; it gets 204.