API for developers

1. Get an API key

API access is part of the Pro plan. Create a key in Settings → API keys. It is shown once: store it like a password. You can have three keys and revoke any of them at once; replacing your access key ends them all.

Send the key with every request:

Authorization: Bearer dk_…

2. Search

POST https://duckint.cc/api/v1/search runs one search and answers when every source has finished, usually within 30 seconds. Give your client a timeout of at least 90 seconds.

curl -s https://duckint.cc/api/v1/search \
  -H "Authorization: Bearer $DUCKINT_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"query": "example.com", "kind": "domain"}'

The answer:

{
  "ok": true,
  "data": {
    "searchId": "…",
    "query": { "normalized": "example.com", "intents": [{ "kind": "domain", "value": "example.com" }] },
    "outcome": "results",
    "charged": true,
    "durationMs": 8123,
    "quota": { "limit": 25, "used": 3, "remaining": 22, "date": "…" },
    "checks": [{ "capability": "rdap-domain", "providerName": "RDAP", "status": "results", "resultCount": 1 }],
    "skipped": [{ "capability": "hunter-domain", "reason": "excluded", "detail": "…" }],
    "results": [{ "key": "…", "type": "domain-registration", "title": "…", "fields": [], "sources": [], "data": {} }]
  }
}

Results have the same shape as the site's JSON export. Raw provider payloads are never included, and neither are leaked passwords: the API tells you where a credential leaked, not the credential. Open the search on duckint.cc to reveal one.

3. Check a key

GET https://duckint.cc/api/v1/me returns the account's username, plan and today's searches, without running a search.

curl -s https://duckint.cc/api/v1/me -H "Authorization: Bearer $DUCKINT_API_KEY"

4. Limits

• The same daily allowance as your account (Pro has no daily limit); a search that finds nothing is not charged.
• At most 250 API search requests per account in 24 hours, across all its keys, even ones that find nothing; the X-API-Daily-Remaining header shows what is left.
• Need more? It can be raised for an extra fee: Contact us
• At most 30 requests a minute per key, on top of the site's limits on searches per minute and searches running at once.
• Searches made with a key appear in your history like any other, and follow the same retention.
• Acceptable use policy: no stalking, harassment or searching people without a lawful reason.

5. Errors

Errors answer {"ok": false, "error": {"code": "…", "message": "…"}} with these statuses: