how wall locations work

2026-02-26

no accounts on sych0net. you show up, post, leave. so how do you tag where a message came from without tracking anyone?

cloudflare, the worker I’m using, tags every request with a 3-letter datacenter code - EWR for newark, LAX for LA, NRT for tokyo. not personal data, just which building your packets passed through. but raw airport codes looked like a departure board so each one gets a generated prefix or suffix on first use. V0id-EWR, LAX-inTeRfAce. cached in KV forever so the same datacenter always gets the same name. instant bbs names!

doesn’t identify you and two people in the same city get the same tag. vpn users get whatever datacenter the vpn exits through, more of a digital postmark than address. If you’re posting from Dr1ft-SIN your packets took a detour through singapore, unless you live there.

interface Env {  WALL_KV: KVNamespace;  ALLOWED_ORIGINS: string;}interface WallEntry {  name: string;  location: string;  message: string;  date: string;}const MAX_NAME = 20;const MAX_MSG = 140;const MAX_MESSAGES = 500;const RATE_LIMIT_SEC = 60;const PREFIXES = [  'Ne0n', 'vEcT0r', 'ShAd0w', 'c1pHer', 'N3xUs', '0mEga',  'Hex', 'z3r0', 'V0id', 'fLux', 'KeRnEl', 'raZ0r',  'SpEcTer', 'haV0c', 'Dr1ft', 'waRp', 'PuLse',  'quAnTa', 'SaBle', 'xeN0'];const SUFFIXES = [  'n0De', 'c0Re', 'maTrIx', 'gr1d', 'huB',  'reLay', 'seCt0r', 'gaTeWay', 'teRmInAl',  'maInFrAme', 'arChIve', 'vaUlT', 'daTaBaNk',  'c1rCuIt', 'prOxy', 'clUsTer', 'saNdBox',  'arRay', 'piPeLiNe', 'inTeRfAce'];function hashColo(colo: string): number {  let h = 0;  for (let i = 0; i < colo.length; i++) {    h = (h * 31 + colo.charCodeAt(i)) | 0;  }  return Math.abs(h);}async function getBoardName(colo: string, kv: KVNamespace): Promise<string> {  const key = `board:${colo}`;  const cached = await kv.get(key);  if (cached) return cached;  const h = hashColo(colo);  const usePrefix = h % 2 === 0;  let name: string;  if (usePrefix) {    name = PREFIXES[h % PREFIXES.length] + '-' + colo;  } else {    name = colo + '-' + SUFFIXES[h % SUFFIXES.length];  }  await kv.put(key, name);  return name;}function corsHeaders(origin: string) {  return {    'Access-Control-Allow-Origin': origin,    'Access-Control-Allow-Methods': 'GET, POST, OPTIONS',    'Access-Control-Allow-Headers': 'Content-Type',  };}function json(data: unknown, status: number, origin: string) {  return new Response(JSON.stringify(data), {    status,    headers: { 'Content-Type': 'application/json', ...corsHeaders(origin) },  });}export default {  async fetch(request: Request, env: Env): Promise<Response> {    const allowed = (env.ALLOWED_ORIGINS || '*').split(',').map(s => s.trim());    const reqOrigin = request.headers.get('Origin') || '';    const origin = allowed.includes('*') ? '*' : allowed.includes(reqOrigin) ? reqOrigin : allowed[0];    const url = new URL(request.url);    if (request.method === 'OPTIONS') {      return new Response(null, { status: 204, headers: corsHeaders(origin) });    }    if (url.pathname !== '/api/wall') {      return json({ error: 'Not found' }, 404, origin);    }    if (request.method === 'GET') {      const raw = await env.WALL_KV.get('messages');      const messages: WallEntry[] = raw ? JSON.parse(raw) : [];      return json(messages, 200, origin);    }    if (request.method === 'POST') {      const ip = request.headers.get('CF-Connecting-IP') || 'unknown';      const rateKey = `rate:${ip}`;      const existing = await env.WALL_KV.get(rateKey);      if (existing) {        return json({ error: 'Slow down. 1 message per minute.' }, 429, origin);      }      let body: { name?: string; message?: string };      try {        body = await request.json();      } catch {        return json({ error: 'Invalid JSON' }, 400, origin);      }      const name = (body.name || 'ANONYMOUS').trim().slice(0, MAX_NAME);      const message = (body.message || '').trim().slice(0, MAX_MSG);      if (!message) {        return json({ error: 'Message is required' }, 400, origin);      }      const cf = (request as any).cf || {};      const colo = (cf.colo || '???').toUpperCase();      const location = await getBoardName(colo, env.WALL_KV);      const entry: WallEntry = {        name,        location,        message,        date: new Date().toISOString(),      };      const raw = await env.WALL_KV.get('messages');      const messages: WallEntry[] = raw ? JSON.parse(raw) : [];      messages.unshift(entry);      if (messages.length > MAX_MESSAGES) messages.length = MAX_MESSAGES;      await env.WALL_KV.put('messages', JSON.stringify(messages));      await env.WALL_KV.put(rateKey, '1', { expirationTtl: RATE_LIMIT_SEC });      return json(entry, 201, origin);    }    return json({ error: 'Method not allowed' }, 405, origin);  },};