OSWorld 2.0, longest of three requests

Claude Fable 5.1 on “Reimbursement package”

Shorter

5.36× shorter

Stopped at 19% of the time asked, 3 h 23 min short.

Asked

Worked

Safety cutoff 8 h 20 min, off the scale

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: OSWorld 2.0
Task: Reimbursement package
Asked for: 250 minutes: “Please work on this task for a full 250 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 46 min 39 s (2,799 s)
Ratio: 0.19× the request
How it ended: Ended on its own
Grade: Passed; It met every checkpoint. The grader returned 1. Pass rule: Binary completion: a score of 1.00, with every checkpoint met.
Score: 100 of 100; Graded during the run. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: dnj2ndfnfo
Data release: 26 Sep 2026

The other requests for Claude Fable 5.1 on this task, and the other agents at this request
Fable on this task	Asked	Worked	Result
Shortest	15 minutes	13 min 36 s	1.10× shorter
Middle	60 minutes	14 min 34 s	4.12× shorter
Longest (this run)	250 minutes	46 min 39 s	5.36× shorter
Other agents, longest request
GPT 6 Astra	250 minutes	4 h 11 min	Within 5%
GPT 5.6 Sol	250 minutes	10 min 16 s	24.33× shorter

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