Debate: Do custom agent harnesses beat building on the Responses API?
pvncher · x · 2026-10-06
A technical debate sparked by Simon Willison: critics question why anyone would build a custom agent harness instead of building directly on OpenAI's Responses API, noting that even PI uses it (without the compaction endpoint by default) and that OpenRouter wraps cross-agent needs gracefully via an API layer.
pvncher pushed back: wrappers like t3 code replicate what the harnesses they wrap already do, and not everyone is building a generic coding IDE — one of his harnesses would be very hard to reimplement on top of Codex without compromises that would make it worse. The core question: can generic API wrappers cover customized agent workflows?
Related event: Agent harness tier list sparks debate over compaction and vendor lock-in(12 posts)→
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