

Anthropic right now is launching Claude Fable 5, a safe-for-use Mythos class mannequin, and is launching Claude Mythos 5 to a small group of safety and infrastructure suppliers that has some safefguards lifted.
Fable 5 has safeguards that may forestall its cybersecurity capabilities from being misused. The safeguards be certain that queries on sure subjects will probably be answered by Claude Opus 4.8. In the meantime, Mythos 5 will probably be deployed via the corporate’s Challenge Glasswing as an uprade to Mythos Preview. The corporate claims this new mannequin has the strongest cybersecurity capabilities of any mannequin. A trusted entry program will quickly be in place to broaden Mythos 5.
In its weblog announcement, Anthropic wrote: “The capabilities of fashions like Fable 5 and Mythos 5 have the potential to do profound good for the world. We’ve seen the beginnings of this in Challenge Glasswing, the place the fashions have helped cyber defenders safe critically essential software program. We’ve additionally seen it in life sciences analysis, the place the fashions are positing novel hypotheses and rushing up the event of recent therapeutics.”
The brand new fashions have been proven to work extra autonomously than any earlier Claude fashions, the corporate wrote. For software program engineers, Anthropic reported that Fable 5 “compressed months of engineering into days.” Of their take a look at, they mentioned a Ruby codebase with 50 million strains was migrated in a day, which might have taken a complete workforce greater than two months to finish by hand. The mannequin’s improved capabilities additionally prolong to information work, imaginative and prescient, reminiscence, and life sciences analysis.
“Fable 5 is an actual step ahead for the builders GitHub serves,” mentioned a spokesperson for GitHub. “In our early testing, it took on complicated, long-horizon coding duties with a degree of autonomy and reliability that exceeded earlier benchmarks. However what excites us most is the route it
factors: a future the place builders can hand more and more formidable work to brokers and belief the outcomes throughout the software program lifecycle.”
Fable 5 and Mythos 5 are being provided at $10 per million enter tokens and $50 per million output tokens—lower than half the value of Claude Mythos Preview. In the present day’s joint launch is one other step in direction of our objective of bringing superior AI capabilities to as many customers as potential, as shortly and as safely as we are able to.
The corporate can be including information privateness protections, comparable to logging human entry to the information, and making certain the information will probably be deleted after 30 days, normally.
Availability
Whereas Claude Fable 5 is obtainable all over the place right now, Mythos 5 is proscribed to Glasswing companions, with a number of the cyber safeguards lifted. Builders can use claude-fable-5 by way of the Claude API.
A conservative staged rollout of subscription plans is as follows, per the corporate:
- From right now via June 22, Fable 5 is included on Professional, Max, Staff, and seat-based Enterprise plans at no further value.
- On June 23, we’ll take away Fable 5 from these plans. Utilizing it after that can require utilization credit. If capability permits, we’ll prolong the included window.
- After this level—when enough capability permits us to take action—we goal to revive Fable 5 as an ordinary a part of subscription plans. We intend to do that as shortly as we are able to.
