Request & Response Objects

Every Amber controller delegates request and response to the current HTTP::Server::Context. Use Amber's controller helpers for ordinary rendering, redirects, and negotiated responses; reach for the underlying Crystal objects when you need a header, method, resource, or status directly.

Request

request is Crystal's HTTP::Request with Amber routing extensions.

File: src/controllers/diagnostics_controller.cr — place this action inside DiagnosticsController, then register it in config/routes.cr.

class DiagnosticsController < ApplicationController
  def show
    method = request.method
    resource = request.resource
    user_agent = request.headers["User-Agent"]?
    query = request.query

    respond_with do
      json({method: method, resource: resource, user_agent: user_agent, query: query}.to_json)
    end
  end
end

Common controller-level helpers include:

The raw request body is an IO. A parser or request schema is usually a better boundary for JSON or form input than manually reading the stream in each action.

Response

response is Crystal's HTTP::Server::Response. Its most useful direct properties are status_code, headers, and content_type.

File: src/controllers/health_controller.cr — place this action inside HealthController, then register it in config/routes.cr.

class HealthController < ApplicationController
  def show
    response.headers["Cache-Control"] = "no-store"
    set_response(
      body: "ok",
      status_code: 200,
      content_type: "text/plain"
    )
  end
end

File: a controller action under src/controllers/ — use respond_with when that action offers these representations.

respond_with do
  html render("show.ecr")
  json({status: "ok"}.to_json)
  text "ok"
end

File: a controller filter or action under src/controllers/ — use halt! when the pipeline must stop with a plain response.

halt!(403, "forbidden") unless authorized?

File: a controller action under src/controllers/ — use the redirect helper rather than setting a Location header by hand.

redirect_to location: "/login", status: 302

For the upstream object APIs, see Crystal's HTTP::Request and HTTP::Server::Response reference. Amber-specific helpers and schema integration should remain the first choice when they express the intent.