Benchmark Almanac

Anthropic large agent teams tasks

Only in system cards

Internal 24-hour tasks for teams of 1-100 agents: build a company knowledge base, or formalize a theorem in Lean.

New in the Opus 5.5 card. Measures capability and alignment of large agent teams.

Made by Anthropic Released Sep 2026 Multi-agent games Tasks kept private Last in a system card Sep 2026 Last model added Sep 2026
Level
Research frontier Researchers, on open problems or tasks that take days
Scored
Checked automatically A program checks the result against an answer key, unit tests or the expected final state.
Answers
Agent task Many steps in a terminal, browser, desktop, app, game or robot.
1
System card reports it, from 1 lab

No scores here yet

No lab, leaderboard or Epoch AI run has reported a score for Anthropic large agent teams tasks yet.

Labs report it only in system cards

We read the headline results of 479 launch posts from 51 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.

DateDocumentScoreAs the document writes itSection
22 Sep 2026 Claude Opus 5.5 system card Large agent teams, 24-hour tasks, no overall: knowledge base 0.74 and Lean formalization 0.68 with 100 agents (single agent 0.53 and 0.39), printed on charts, slightly different model version (8.12.3, Figures 8.12.3.A and B) Capabilities

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  • GameWorld Only in system cards Multimodal game agents play 34 browser games across 170 tasks. Outcomes are checked from the game state. Gemini 3 Flash 41.9%
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