Terminal-Bench 4.0, longest of three requests

Claude Fable 5.1 on “Generate physically valid walking, jumping, and running trajectories”

Shorter

1.61× shorter

Stopped at 62% of the time asked, 1 h 54 min short.

Asked for
300 minutes
Worked
3 h 6 min
Grade
Passed
Score 100 of 100. Graded during the run.
How it ended
Ended on its own
Every detail of this run
Agent
Claude Fable 5.1, in Claude Code
Asked for
300 minutes: “Please work on this task for a full 300 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked
3 h 6 min (11,153 s)
Ratio
0.62× the request
How it ended
Ended on its own
Grade
Passed
It passed the task's tests. The grader returned 1. Pass rule: The task's tests pass.
Score
100 of 100
Graded during the run. The paper's value.
Wording
The standard sentence, used from 4 September 2026.
Run id
lfp52xasnf
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 taskAskedWorkedSplitResult
Shortest20 minutes56 min 9 s2.81× longer
Middle80 minutes1 h 52 min1.40× longer
Longest (this run)300 minutes3 h 6 min1.61× shorter
Other agents, longest request
GPT 6 Astra300 minutes5 h 2 minWithin 5%
GPT 5.6 Sol300 minutes34 min 46 s8.63× shorter

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Data and citation

Upstream: Merrill et al., 2026 (ICLR)