Terminal-Bench 4.0, longest of three requests

Claude Fable 5.1 on “Resolve a 20-claim heat-pump warranty exception queue”

Shorter

1.72× shorter

Stopped at 58% of the time asked, 25 min 13 s short.

Asked for
60 minutes
Worked
34 min 47 s
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
60 minutes: “Please work on this task for a full 60 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked
34 min 47 s (2,087 s)
Ratio
0.58× 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
wcvc7x4vtl
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
Shortest4 minutes14 min 50 s3.71× longer
Middle15 minutes23 min 51 s1.59× longer
Longest (this run)60 minutes34 min 47 s1.72× shorter
Other agents, longest request
GPT 6 Astra60 minutes1 h 1 minWithin 5%
GPT 5.6 Sol60 minutes1 h 2 minWithin 5%

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Data and citation

Upstream: Merrill et al., 2026 (ICLR)