API keys are optional. Anonymous requests are allowed (rate-limited by IP); a key ties usage to your account and, on a paid plan, raises your limit. Even free accounts can create a key — it’s still subject to the free limit.
Create a key
Sign in, go to Dashboard → API, and create a key. The token is shown once — copy it then; we store only a hash and can’t show it again. Revoke a key any time from the same page.
Send the key
Pass it as a Bearer token:
curl -H "Authorization: Bearer ipk_xxx" \
https://ipcow.com/api/whats-my-ip?raw
Or with the X-API-Key header:
curl -H "X-API-Key: ipk_xxx" \
"https://ipcow.com/api/tools/dns-check?domain=example.com"
Keep it secret
A key identifies your account — treat it like a password. If one leaks, revoke it in the dashboard and create a new one. Keys grant no extra tool access (every tool is public); they only set which rate-limit bucket and limit apply. See Rate limits.