About Source CIDR
What this is
Source CIDR is a curated registry of official IP range publications, ASN context, and verification guidance for crawlers, AI platforms, CDNs, cloud providers, and developer tools.
We link to vendor-published feeds and documentation where they exist. We do not scrape, guess, or reverse-engineer IP ranges from BGP dumps - if a vendor publishes a JSON, TXT, or CSV of their addresses, we point to it.
How entries are categorized
- Official
- IP ranges sourced directly from the vendor's published feed (JSON, TXT, CSV, or API endpoint).
- Maintained
- Ranges aggregated, deduplicated, or mirrored here on Source CIDR when no single vendor feed exists.
- ASN
- Autonomous System Numbers associated with a company - useful as BGP context but not a substitute for IP-level allowlists.
- Documentation
- Links to official vendor documentation that describes IP ranges without providing a machine-readable feed.
Catalog JSON
Every entry with an official or maintained feed is published in /catalog.json - a
machine-readable index designed for automation. See the Catalog API documentation for the schema and usage examples.
What this is not
This registry is a reference tool, not an authentication service. Listing an IP range here does not guarantee that traffic from that range is legitimate. Always cross-check official sources, use rDNS verification where documented, and validate webhook signatures rather than relying on IP allowlists alone.
Open source
Source CIDR is currently maintained manually. The plan is to open-source the project (or at least the data layer) so that companies and individuals can submit their own CIDR lists, ASNs, and feed URLs directly via pull requests - rather than relying on one person to discover and add every entry.
If you represent an organization and want your IP ranges listed here, or if you'd like to contribute when the repo opens up, reach out and we'll keep you in the loop.
Contact
Built and maintained by Divyendra Patil. Corrections, additions, or questions: hello@divyendra.com.