OSWorld 2.0, longest of three requests

Claude Fable 5.1 on “FreeCAD bracket”

Longer

2.04× longer

Worked 104% past the request, 4 h 20 min over.

Asked

Worked

Dashed line: safety cutoff at 8 h 20 min

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: OSWorld 2.0
Task: FreeCAD bracket
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: 8 h 30 min (30,600 s)
Ratio: 2.04× the request
How it ended: Stopped by the safety cutoff
Grade: Did not pass; It did not meet every checkpoint. The grader returned 0.789. Pass rule: Binary completion: a score of 1.00, with every checkpoint met.
Score: 78.9 of 100; Graded during the run. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: 72vbafbjek
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	12 min 52 s	1.17× shorter
Middle	60 minutes	42 min 28 s	1.41× shorter
Longest (this run)	250 minutes	8 h 30 min	2.04× longer
Other agents, longest request
GPT 6 Astra	250 minutes	4 h 11 min	Within 5%
GPT 5.6 Sol	250 minutes	35 min 40 s	7.01× shorter

See it on the chart. Transcripts are not published yet.

Read before quoting. This run was stopped by the safety cutoff, so its time is a lower bound: the agent might have kept going. Details

Data and citation