Teknium: same task fails on Astra but succeeds on Fable — model or harness?

Teknium · x · 2026-09-07

Teknium reports that after Astra failed on his task, switching to Fable resolved everything quickly — evidence, he argues, of a model issue rather than a harness issue.

He questions whether OpenAI trains its models to work only in a specific harness, noting that harness tooling is in flux everywhere, making such tight coupling questionable.

Related event: Teknium Details Hermes Sub-Agent Design and Questions OpenAI's Harness Ties(3 posts)→

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