Terminal-Bench 4.0, middle of three requests

Claude Fable 5.1 on “Port an Excel/VBA service-desk app to React, FastAPI, and SQLite”

Shorter

1.45× shorter

Stopped at 69% of the time asked, 12 min 21 s short.

Asked for
40 minutes
Worked
27 min 39 s
Grade
Did not pass
Score 0 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
40 minutes: “Please work on this task for a full 40 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked
27 min 39 s (1,659 s)
Ratio
0.69× the request
How it ended
Ended on its own
Grade
Did not pass
It did not pass the task's tests. The grader returned 0. Pass rule: The task's tests pass.
Score
0 of 100
Graded during the run. The paper's value.
Wording
The standard sentence, used from 4 September 2026.
Run id
d7pnvpe6w2
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
Shortest10 minutes28 min2.80× longer
Middle (this run)40 minutes27 min 39 s1.45× shorter
Longest150 minutes40 min 33 s3.70× shorter
Other agents, middle request
GPT 6 Astra40 minutes40 min 26 sWithin 5%
GPT 5.6 Sol40 minutes40 min 25 sWithin 5%

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Data and citation

Upstream: Merrill et al., 2026 (ICLR)