API

One base URL, bearer auth, form or JSON bodies. Create a token in your dashboard.

Create a link

POST https://u4.nz/api/links
Authorization: Bearer $U4_TOKEN

url      required   http(s) destination
slug     optional   custom slug; omit for a generated one
expires  optional   days until the link stops resolving

curl -X POST https://u4.nz/api/links \
  -H "Authorization: Bearer $U4_TOKEN" \
  -d url="https://example.com/launch" -d slug=launch -d expires=30

{
  "slug": "launch",
  "short": "https://u4.nz/launch",
  "url": "https://example.com/launch",
  "expires_at": 1794412800000,
  "clicks": 0
}

List your links

curl https://u4.nz/api/links -H "Authorization: Bearer $U4_TOKEN"

Click stats

curl https://u4.nz/api/links/launch/stats -H "Authorization: Bearer $U4_TOKEN"

{
  "slug": "launch",
  "clicks": 412,
  "window_days": 30,
  "by_day":     [{"day":"2026-09-14","n":37}],
  "by_country": [{"k":"NZ","n":121}],
  "by_referer": [{"k":"news.ycombinator.com","n":88}],
  "by_device":  [{"k":"mobile","n":240}]
}

Delete a link

curl -X DELETE https://u4.nz/api/links/launch -H "Authorization: Bearer $U4_TOKEN"

Errors and limits

Errors are {"error":"..."} with a meaningful status: 400 bad URL or slug, 401 bad token, 404 no such link, 409 slug taken, 429 rate limited.

Anonymous creation from the home page is limited per IP. Authenticated creation is limited per token. Redirects are not limited.