ctx.flash()

A flash is a one-time message that survives one redirect, such as "Saved" after a form post.

Setting a flash

return ctx.res.redirect('/account', { flash: 'Saved' })

The message is stored as JSON in a cookie (pp_flash, HttpOnly, Max-Age=300). It can be any JSON value:

return ctx.res.redirect('/cart', { flash: { type: 'success', text: 'Added to cart' } })

Reading it

On the next request, ctx.flash() returns the message and clears the cookie. It returns undefined when there is none. Calling it again in the same request returns the same value.

<% const flash = ctx.flash() %>
<% if (flash) { %>
  <div class="alert alert-<%= flash.type %>"><%= flash.text %></div>
<% } %>

Read it in your layout to show flashes on every page.