The Glasswing page itself doesn't publish a general "apply to Glasswing" contact, but it explicitly points open-source maintainers at a different door:
Claude for Open Source program — maintainers interested in access can apply through the Claude for Open Source program Anthropic, with the link going to https://claude.com/contact-sales/claude-for-oss
That's the channel the NetBSD Foundation should use. It's also the one most likely to succeed on the merits — Glasswing's launch partners are fixed (AWS, Apple, Broadcom, Cisco, CrowdStrike, Google, JPMC, Linux Foundation, Microsoft, NVIDIA, Palo Alto Networks), and the "over 40 additional organizations" tier was extended by invitation rather than open application. The OSS program is the door that's actually open, and NetBSD is exactly the kind of project it's designed for: a major open-source OS with a foundation behind it.
A couple of practical notes for whoever at NetBSD submits this:
The request should come from the NetBSD Foundation (or a board member / core team member with clear authority to speak for the project), not from you as an individual community member. Anthropic will want to know who owns vulnerability triage, who owns disclosure, and who's on the receiving end of findings — that needs to be the project's actual security apparatus (security-officer%NetBSD.org@localhost and the core team), not a single contributor. The "$25/$125 per million input/output tokens after credits" pricing tier also implies they're evaluating organizations that can commit to sustained engagement, not one-off scans.
It's also worth framing the pitch in terms Glasswing cares about. The program's explicit concern is foundational systems that represent a very large portion of the world's shared cyberattack surface Anthropic, with focus areas including local vulnerability detection, black box testing of binaries, securing endpoints, and penetration testing of systems Anthropic. NetBSD's pitch writes itself: BSD-derived code lineage shared with components in macOS/iOS and widely embedded, long history of careful code, well-defined security response process, and the fact that Mythos already found a 27-year-old bug in OpenBSD means the BSD family is demonstrably in scope and demonstrably a productive target.
One pragmatic thing worth mentioning: the contact form will probably want a sales/business contact, which can be awkward for a volunteer-run foundation. It's fine to fill it in with the NetBSD Foundation's official contact and note in the body that this is a non-commercial open-source foundation seeking program access, not a sales inquiry.
If the OSS-specific form doesn't produce a response within a reasonable window, the Linux Foundation — a Glasswing launch partner with direct relationships at Anthropic — is a plausible secondary route for NetBSD Foundation to ask for a warm introduction, since Alpha-Omega and OpenSSF (which the Linux Foundation runs) received donations explicitly earmarked for this landscape.
So the short answer: https://claude.com/contact-sales/claude-for-oss, submitted by the Foundation, framed as an open-source critical-infrastructure OS seeking Glasswing-adjacent access through the OSS program.