DeepSWE v1.1, shortest of three requests

Claude Fable 5.1 on “Add server-sent-event streaming endpoints to Effect HttpApi”

Longer

1.28× longer

Worked 28% past the request, 2 min 14 s over.

Asked

Worked

Safety cutoff 4 h 10 min, off the scale

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: DeepSWE v1.1
Task: Add server-sent-event streaming endpoints to Effect HttpApi
Asked for: 8 minutes: “Please work on this task for a full 8 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 10 min 14 s (614 s)
Ratio: 1.28× the request
How it ended: Ending not labelled yet
Grade: Did not pass; It did not pass its hidden tests. The grader returned 0. Pass rule: The hidden 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: nzz2irsj6d
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 (this run)	8 minutes	10 min 14 s	1.28× longer
Middle	30 minutes	28 min 14 s	1.06× shorter
Longest	125 minutes	35 min 21 s	3.54× shorter
Other agents, shortest request
GPT 6 Astra	8 minutes	11 min 29 s	1.44× longer
GPT 5.6 Sol	8 minutes	16 min 7 s	2.01× longer

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Read before quoting. How this run ended has not been labelled yet. It is timed like every other run and counted in every number. Details

Data and citation