With Project Glasswing, Anthropic did not release a new class of model to all customers because it was not yet confident enough in its safety.

True if, as of 2026-06-29, the evidence shows that under Project Glasswing Anthropic made a new class of model available only to a limited set of partners or customers, not all customers, and that Anthropic itself gave not yet being confident enough in its safety (or in its safeguards against misuse) as a reason for withholding general release. Mostly true if the limited release and the safety-confidence reason both hold but a minor detail is off, for example the reason given was mainly cybersecurity misuse risk rather than safety in general, or the model is described somewhat differently. Mixed if the model was withheld from general release but the stated reason was mainly something else (compute, commercial or capacity reasons), with safety only one factor among several. Mostly false if Project Glasswing exists but involved no withheld new model class, or if the model had in fact been released broadly. False if there was no such project, or if the model was generally available to all customers as of the claim date.

Set before the research began.

1. E1 Expanding Project Glasswing Anthropic · 2 June 2026 Own record

   “We’re working as quickly as we can to safely release Mythos-level capabilities in general access. To do so, we’ll need highly robust safeguards that prevent the model’s cyber capabilities from being misused—safeguards that we (and, to our knowledge, all other AI developers) have yet to develop.”

2. E2 Project Glasswing: An initial update Anthropic · 22 May 2026 Own record

   “At present, no company—including Anthropic—has developed safeguards strong enough to prevent such models from being misused and potentially causing severe harm. That is why we have yet to release Mythos-class models to the public.”

3. E3 Project Glasswing Anthropic · 7 April 2026 Own record

   “Mythos Preview has already identified thousands of zero-day vulnerabilities across critical infrastructure, and is available today as a gated research preview.”

4. E4 Anthropic co-founder Daniela Amodei urges students to combine innovation with responsibility The Stanford Daily · 8 May 2026

   “It’s uncomfortable to say to your customer, ‘We understand that desire, we want to get this technology to use as quickly as possible, but it is irresponsible of us to release it until we are confident that all of the patching that needs to be done is done.'”

Anthropic's official Project Glasswing page shows that the new model, Mythos Preview, was made available as a gated research preview (E3). They also show that Anthropic had not released Mythos-class models to the public as of May–June 2026 (E2, E1). Anthropic said it was holding back general release because safeguards against cyber misuse were not yet strong enough (E1, E2), and independent reporting quotes Amodei saying it would be irresponsible to release until Anthropic is confident the needed patching is done (E4). Both the limited release and the stated reason are confirmed, but the reason was specifically cybersecurity misuse rather than safety in general, which the criteria count as mostly true.