## Description / Steps to reproduce / Feature proposal For DP3, we'd like inputs from http requests to be validated using a given OpenAPI spec. - Follow up to #1306 ## Acceptance Criteria - [ ] Use the validator engine from #1294 in `parseParams` (instead of in the method decorator) to validate the coerced parameters using an OpenAPI spec <!-- HELP US HELP YOU, PLEASE - Do a quick search to avoid duplicate issues - Provide as much information as possible (reproduction sandbox, use case for features, etc.) - Consider using a more suitable venue for questions such as Stack Overflow, Gitter, etc. --> _See [Reporting Issues](http://loopback.io/doc/en/contrib/Reporting-issues.html) for more tips on writing good issues_