Anthropic uses an unpublished AI model called "Model 2" internally

Anthropic is running an unreleased AI model called "Model 2" internally that outperforms every publicly available version of Claude, according to the company's Risk Report from August 2026. The model, placed in the Mythos class, scores about 1.5 points above Claude Mythos 5 on Anthropic's internal capability index (AECI) and is used heavily for coding, data generation, and research. Anthropic rates the overall risk from misalignment as "low" and has no plans to release the model externally.

Anthropic uses an unpublished AI model called "Model 2" internally Anthropic is running an unreleased AI model internally that outperforms every publicly available version of Claude. That's according to the company's Risk Report from August 2026. The report calls the model "Model 2" and places it in the Mythos class. Anthropic says it's slightly stronger overall than Claude Mythos 5, but weaker in some areas. It doesn't show a big capability jump like the one from Opus 4.6 to Mythos. On the company's internal capability index, AECI, it sits about 1.5 points above Mythos 5. That gain is smaller than the jump from Mythos Preview to Mythos 5. Internally, the company leans on the model heavily for coding, data generation, and research and engineering, sometimes through agents that run continuously. Claude now writes most of the code in Anthropic's production systems. Model 2 went through an internal review before deployment, but wasn't tested as thoroughly as Mythos 5. Anthropic found no new or more worrying misalignments in the process. The company rates the overall risk from misalignment as "low." There are no plans to release the model externally right now. AI News Without the Hype – Curated by Humans Subscribe to THE DECODER for ad-free reading, a weekly AI newsletter, our exclusive "AI Radar" frontier report six times a year, full archive access, and access to our comment section. Subscribe now Anthropic https://www-cdn.anthropic.com/f61d49fa5596956a5dec75fea0e973bf6a6a8378/Redacted%20Risk%20Report%20August%202026%20.pdf