Grails 6 Tutorials — GroovyGrails.in

Building REST APIs

Grails makes APIs simple with response formats and JSON views.

class BookRestController {
  static responseFormats = ['json','xml']

  def index() { respond Book.list() }

  def save() {
    def b = new Book(request.JSON)
    if (b.save()) respond b, [status:201] else respond b.errors, [status:422]
  }
}

Versioning

Common pattern: include version in URL (e.g. /api/v1/books) or use header-based versioning.