The /_dev Panel

While you write an app, /_dev shows what the last requests did: which component answered, which q:action ran, every query with its parameters, time and rows, the variables each scope ended with, the redirect and the flash.

Turn it on in quantum.config.yaml:

server:
  debug: true
  host: 127.0.0.1

quantum start prints the address (Dev panel: http://localhost:8080/_dev). Use the app, then open /_dev: the newest request is shown, and each row of the list opens its own request (/_dev/12).

Section	What it shows
Component, Action	the .q file that answered and the action a POST ran
Redirect, Flash	where an action sent the browser, and the message for the next page
Queries	datasource, SQL, parameters, rows (or the database's error), time
action / page	the variables the action or the page ended with
session / application	the scopes as they were at the end of the request

A value longer than 300 characters is cut. Everything is escaped: a variable holding HTML shows as text.

It exists only while developing

• With debug: false nothing is recorded and /_dev is a 404.
• It answers only requests from the machine itself (127.0.0.1 / ::1): the panel shows sessions and query parameters, so from any other address it does not exist — even if the config says debug: true behind a public bind.
• It keeps the last 30 requests of the server process, in memory.