ASN API
Getting started
Subscribe, copy your secret key, and run your first ASN lookup.
The Syndaq ASN API maps a public IP address to its autonomous system, organization, announced network, and a simple network-type classification.
What you need
- An ASN plan from the Syndaq API catalog.
- A secret key (
as_sec_) from the Syndaq client area after your order is provisioned.
ASN lookups are server-side only. Send your secret key from your backend or trusted worker. Do not embed it in client-side code, mobile apps, or public repositories.
Base URL
All ASN endpoints are served from:
https://api.syndaq.com/v1/asn/Quick start
Replace as_sec_YOUR_SECRET_KEY with the secret shown in Services for your ASN subscription.
curl -sS "https://api.syndaq.com/v1/asn/lookup/8.8.8.8" \
-H "Authorization: Bearer as_sec_YOUR_SECRET_KEY"You can also pass the IP as a query parameter:
curl -sS "https://api.syndaq.com/v1/asn/lookup?ip=8.8.8.8" \
-H "Authorization: Bearer as_sec_YOUR_SECRET_KEY"A successful response includes asn, as_org, network, country_code, and network_type.
How lookups work
| Step | What happens |
|---|---|
| 1 | Authenticate with your secret key. |
| 2 | Send a lookup request to the API. |
| 3 | Receive JSON with the result fields (including a cached flag when Syndaq already holds a recent result). |
Private, reserved, and invalid addresses return a clear error.
GeoIP vs ASN
| Product | Best for |
|---|---|
| GeoIP | Country, city, coordinates, ISP, and EU membership |
| ASN | AS number, org name, announced prefix, and hosting vs ISP-style classification |
Manage your subscription
Sign in to the Syndaq client area and open Services. Select your ASN service to:
- View usage and remaining monthly quota
- Copy or rotate your secret key
- Configure optional IP allowlists for API access
Next steps
- Authentication and limits: keys, rate limits, quotas, and IP restrictions
- API reference: endpoints, response fields, and error codes