Key insight rediscovery on an unpublished ML task (external testing)
Agents work on an unpublished machine learning research task. Testers count how many of five key insights the agent rediscovers.
Run by an unnamed external testing partner on a pre-release snapshot. The task is not public.
- Made by
- Anthropic
- Kind
- AI research tasks
- Level
- Research frontier
- Scored
- Graded by people
- Answers
- Agent task
- Tasks
- Kept private
- Last in a system card
- April 2026
- Last model added
- April 2026
Claude Mythos Preview leads with 80%
Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.
Source: Labs’ model cards
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Claude Mythos Preview | 80% | Apr 2026 | Lab model card |
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Source: Labs’ model cards
Labs report it only in system cards
We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark. Some system cards do, below.
One system card reports it
Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.
| Date | Document | Score | As the document writes it | Section |
|---|---|---|---|---|
| Apr 7, 2026 | Claude Mythos Preview system card | 80 | External testing of an early snapshot, unpublished machine learning task, rediscovered 4/5 key insights (2.3.7) | AI R&D risk |
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