flino.link

🇪🇸 Versión en español

Personal URL shortener running in production on Cloudflare's edge network. Links are served at flino.link/<slug>; the root and unknown slugs redirect to flino.dev.

Demo: https://flino.link/me

Redirect latency	< 10 ms from 300+ edge locations
Servers	0 (pure serverless, no perceptible cold starts)
Operating cost	$0/mo infrastructure · $4.68/yr domain
Capacity (free tier)	~100,000 requests/day
Stack	TypeScript · Cloudflare Workers · KV · Durable Objects
Runtime dependencies	None — no frameworks, no npm in production

Why

Two goals: short links under my own brand (every shared link points traffic back to flino.dev), and building a complete system — DNS, edge computing, distributed storage, auth, dashboard — running in real production at zero cost.

Architecture

flowchart LR
    U((Visitor)) -->|GET /abc123| W[Worker\nflino-link]
    W -->|slug → URL| KV[(Workers KV)]
    W -->|302 redirect| U
    W -.->|"waitUntil (async,\nno added latency)"| DO[(Durable Object\nClickCounter\nSQLite)]
    A((Admin)) -->|Bearer API key| API[/REST API\n/api/links/]
    API --> KV
    API --> DO
    A -->|/admin| D[Dashboard\ninline HTML]

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A single Worker serves the whole domain:

• Redirects — the hot path. One KV read (globally replicated, served from the edge) and a 302. Nothing else touches that path.
• Click counting — a Durable Object with embedded SQLite stores slug → (count, last_click). The increment runs inside ctx.waitUntil(): it executes after the response is sent, so counting clicks adds zero latency to the redirect.
• REST API — link CRUD with Bearer auth. The key lives as a Worker secret, never in the repo.
• Dashboard (/admin) — a single HTML page served inline from the Worker: create links, copy, delete, and see clicks per link. No framework, no build step, automatic dark mode.

Design decisions

KV for links, a Durable Object for counters. KV is ideal for a shortener's read-heavy, write-light pattern, but its writes are eventually consistent — useless for counting. A Durable Object provides a single point of consistency with transactional SQLite, and it stays out of the read path because counting is asynchronous.

A dedicated domain instead of routes under flino.dev. Shorteners attract abuse (spam, phishing) and end up on blocklists. With a separate domain, that reputation risk stays isolated from my main site.

Random 6-character base62 slugs (~57 billion combinations) generated with crypto.getRandomValues, with optional custom slugs. Reserved slugs (api, admin, …) cannot be assigned.

Fail toward the brand. Unknown slug or root → redirect to flino.dev. A broken link never shows an error; it shows my site.

API

Authentication: Authorization: Bearer <API_KEY> header.

# Create a link (random slug)
curl -X POST https://flino.link/api/links \
  -H "Authorization: Bearer $API_KEY" \
  -d '{"url":"https://example.com/some-long-page"}'
# → { "slug": "pQ4xhx", "url": "…", "shortUrl": "https://flino.link/pQ4xhx" }

# Create a link with a custom slug
curl -X POST https://flino.link/api/links \
  -H "Authorization: Bearer $API_KEY" \
  -d '{"url":"https://github.com/someuser","slug":"gh"}'

# List all links (includes clicks and last click)
curl -H "Authorization: Bearer $API_KEY" https://flino.link/api/links

# Get / delete
curl -H "Authorization: Bearer $API_KEY" https://flino.link/api/links/gh
curl -X DELETE -H "Authorization: Bearer $API_KEY" https://flino.link/api/links/gh

Development

npm install
npm run dev          # uses the API_KEY from .dev.vars (not versioned)

Deployment (one-time setup)

1. In Cloudflare: add the flino.link site and activate the zone (point the registrar's nameservers to the ones Cloudflare assigns).
2. npx wrangler login
3. npx wrangler kv namespace create LINKS and copy the resulting id into wrangler.jsonc.
4. npx wrangler secret put API_KEY (pick a long random key, e.g. openssl rand -hex 32).
5. npm run deploy

Subsequent deploys: just npm run deploy.

Possible extensions

• Richer analytics (country, referrer) with Workers Analytics Engine
• Link expiration (native KV TTL)
• Email at @flino.link via Cloudflare Email Routing