Read & Leave

Created for Week 4 of Shared Minds at NYU ITP (Fall 2024), Read & Leave (notes.lan.codes) is an ephemeral message-sharing application that measures a note's lifespan not by wall-clock time, but by how many times it is read.

Ephemeral Scarcity Mechanics#

Most web applications persist every database row indefinitely. Read & Leave treats attention as a finite resource:

1. Compose & Constrain: Authors write a note and choose how many times it can be viewed (Unlimited, or 1 through 5 reads), generating a shareable capability URL (https://notes.lan.codes/<uuid>).
2. Server-Side Decrement: Opening /${uuid} triggers a force-dynamic Next.js Server Component (getNoteAndUpdate) that queries the Supabase notes table and decrements readTimes on every view.
3. Self-Destruction on Final Read: When readTimes === 1, the server immediately deletes the row from PostgreSQL (supabase.from('notes').delete().eq('uuid', uuid)) as the final reader views the warning: "This is the last time you can view this note. It will not be available after you close this page." Subsequent requests return 404 Not Found.

Supabase Schema & Server Action#

Notes are stored in a Supabase PostgreSQL table (notes) keyed by id and uuid, tracking created_at, text, and a nullable readTimes counter (NULL for unlimited views, or an integer countdown).

export const dynamic = 'force-dynamic';
 
async function getNoteAndUpdate(uuid: string): Promise<Note | null> {
  const supabase = createClient();
 
  const { data: note, error } = await supabase
    .from('notes')
    .select('*')
    .eq('uuid', uuid)
    .single();
 
  if (error || !note) return null;
 
  if (note.readTimes === 1) {
    await supabase.from('notes').delete().eq('uuid', uuid);
  } else if (note.readTimes !== null && note.readTimes > 1) {
    await supabase
      .from('notes')
      .update({ readTimes: note.readTimes - 1 })
      .eq('uuid', uuid);
  }
 
  return note as Note;
}