Documentation

Overview

Go (go.isolatedcommand.com) is a free, open-source URL shortener maintained by the Research and Development (R&D) Team. It is generally available — anyone can create a short link and browse the public directory, with no account required.

It runs entirely on Cloudflare Workers and Workers KV: there is no origin server and no database to operate. Requests are handled at Cloudflare’s global edge, so redirects resolve close to the user, worldwide.

Public: create links and search the whole directory.
Admin (DevComm maintainers): edit, disable, re-enable and delete links, behind Cloudflare Access.

Features

Area	What you get
Short links	Random or custom codes at `go.isolatedcommand.com/<name>`
Directory	Public, searchable list of every link (code, destination, domain)
Analytics	Click count, created date, last-accessed date, status, optional expiry
Security	Scheme allow-list, SSRF protection, blocked domains & keywords, HTTPS-only
Abuse control	Per-IP rate limiting with hashed identifiers and abuse logging
Admin console	Edit / disable / delete, protected by Cloudflare Access
Configuration	Editable JSON blocklists & settings — no code change to update
API	Simple JSON API for create, search and admin actions

Backend technology

Go is deliberately small and serverless. One Worker handles every request.

Layer	Technology	Role
Runtime	Cloudflare Workers	Executes routing, validation, redirects and the API at the edge
Storage	Workers KV	Stores link records (`code → {dest, clicks, status, …}`) as key/value + searchable metadata
Front end	Hugo + the Publisher theme	Static site (home, search, admin, docs), served by the Worker’s assets binding
Auth	Cloudflare Access (Zero Trust)	Authenticates admins; the Worker verifies the Access JWT
Tooling	Wrangler, esbuild	Build & deploy; config JSON is bundled into the Worker

Request flow

Browser ─▶ Cloudflare Edge ─▶ Worker
                                 │
        ┌────────────────────────┼─────────────────────────┐
        ▼                        ▼                          ▼
  /api/*  →  JSON API     path in KV  →  302 redirect   else  →  static site / 404
                          (+ click analytics)

Static assets (home, /search/, /docs/, /admin/) are matched and served by the assets binding before the Worker runs.
/api/* is handled by the Worker’s JSON API.
Any other path is looked up in KV: a match is a 302 redirect (302, not 301, so a link can be disabled or edited and take effect immediately); no match falls through to the static 404.

Data model

Each link is a KV record. Legacy plain-string values are still read transparently.

{
  "dest": "https://example.com/page",
  "created": "2026-07-01T00:00:00.000Z",
  "clicks": 42,
  "lastAccessed": "2026-07-01T09:30:00.000Z",
  "expiry": null,
  "status": "active"
}

The searchable fields are mirrored into KV metadata, so the directory and admin console can list and search links from list() alone — without a read per key. Click counts are incremented after the redirect (in waitUntil) so redirects stay fast.

Security

Security is enforced in the Worker, before any link is stored, so an unsafe or policy-violating destination can never be saved and therefore never served.

URL validation

Every destination must parse as a valid URL and pass all of the following:

Scheme allow-list — only http: and https: are permitted. Unsafe schemes are rejected outright: javascript:, data:, file:, blob:, chrome:, edge:, about:, mailto:, ftp:.
SSRF protection — links to internal or non-routable hosts are blocked: localhost, *.local / *.internal / *.lan, and private / loopback / link-local IP ranges — IPv4 (10/8, 127/8, 169.254/16, 172.16/12, 192.168/16, CGNAT 100.64/10, and more) and IPv6 (::1, fc00::/7, fe80::/10, v4-mapped).
Redirect-loop prevention — a destination can’t point back at the shortener’s own hostnames.
Malformed URLs — anything unparseable is rejected with a friendly message.

Content blocklists

Two editable lists screen destinations:

Blocked domains (config/blocked-domains.json) — the hostname and its subdomains are rejected.
Blocked keywords (config/blocked-keywords.json) — matched (case-insensitively) against the host, path and query.

Update either file and redeploy — no code change. A blocked destination returns a clear message explaining it violates the service policy.

Transport & abuse

HTTPS only — the KV/transport policy requires HTTPS; a non-HTTPS endpoint aborts startup.
Rate limiting — creation is limited per client IP (default 20 / minute). Only hashed IP and User-Agent values are stored (with a timestamp); raw identifiers never touch KV. Repeated violations are logged.

Admin authentication — Cloudflare Access

The /admin page and all /api/admin/* endpoints are protected by Cloudflare Access. Access authenticates the user at the edge and issues a signed JWT; the Worker independently verifies that JWT on every admin request:

RS256 signature against the team’s public keys (JWKS).
iss equals the configured team domain.
aud includes the configured Access application.
exp / nbf are currently valid.

So even a request that reached the API directly cannot mutate data without a valid Access login. The public API is read + create only; all edits, disables and deletes require Access.

Using Go

Create a link

Type your destination on the home page. Optionally set a custom name after the slash — letters, numbers and - . _ ~, up to 64 characters. Reserved words (api, admin, search, docs, links, …) can’t be used. Leave the name blank for a random 6-character code.

Find a link

The Search page reads live from Workers KV. Search by short code, destination URL or domain, page through results, and copy or open any link.

API

Base URL: https://go.isolatedcommand.com

Method & path	Auth	Purpose
`POST /api/links`	public (rate-limited)	Create a link — body `{ "dest": "…", "code": "optional" }`
`GET /api/links?q=&cursor=&limit=`	public	Search / list links
`GET /api/links/:code`	public	Fetch one link
`GET /api/admin/identity`	Access	The signed-in admin’s email
`PATCH /api/admin/links/:code`	Access	Edit `{ dest?, status?, expiry? }`
`DELETE /api/admin/links/:code`	Access	Delete a link
`POST /api/admin/migrate`	Access	Backfill metadata for legacy links

Create example:

curl -X POST https://go.isolatedcommand.com/api/links \
  -H "content-type: application/json" \
  -d '{"dest":"https://example.com/page","code":"demo"}'
# → { "link": { "code": "demo", "shortUrl": "https://go.isolatedcommand.com/demo", ... } }

Configuration

All policy lives in config/*.json, bundled into the Worker at deploy and cached in memory. Edit the JSON and redeploy — no code change required.

File	Controls
`settings.json`	Security switches, rate limits, short-code rules, pagination, Access team domain + AUD
`blocked-domains.json`	Domains rejected outright
`blocked-keywords.json`	Keywords rejected in host/path/query

Self-hosting guide

Go is open source — you can run your own instance.

# 1. Clone
git clone https://github.com/isolatedcommand/Go && cd Go

# 2. Create the KV namespace and paste the ids into wrangler.toml
wrangler kv namespace create SHORT_URLS
wrangler kv namespace create SHORT_URLS --preview

# 3. (Optional) seed initial links
./seed-links.sh

# 4. Deploy — the build step builds the Hugo front end first
wrangler deploy

Point your domain at the Worker (custom domain / route). To enable admin, create a Cloudflare Access self-hosted application for the /admin path and put its team domain + AUD in config/settings.json (or the ACCESS_TEAM_DOMAIN / ACCESS_AUD vars). Add or change a link any time with a single KV write — live worldwide in seconds:

wrangler kv key put --binding SHORT_URLS "/talk" "https://example.com/my-talk"

Contributing

Go is a DevComm community project. Issues and pull requests are welcome on GitHub — whether it’s a blocklist entry, a security hardening, a docs fix or a new feature. Please keep the architecture serverless and the design consistent with the Publisher theme.

Built and maintained by the Research and Development (R&D) Team. Same platform, one deployment, open to all.