# clm_C57418A7863D

subject: Vercel (/record/vercel.md)  
predicate: feature_added  
value: fx harness host adapter  
valid_from: 2026-10-29  
valid_to: null  
published: 2026-10-27  
recorded: 2026-10-29  
confidence: 0.70  
status: valid  
assertable: true  
superseded_by: null  
last_updated: 2026-10-29  
checked: 2026-10-29 · its source page states the value and the date  

> The fx adapter now runs the harness on the host Felix Arntz Software Engineer Blog Changelog 29 Oct 2026 1 min read Copy The fx adapter for the AI SDK’s HarnessAgent now uses libfx , the TypeScript library for fx. The harness and model requests run in your application’s process

What https://vercel.com/changelog/fx-harness-adapter-now-separates-host-and-sandbox says, word for word.

## Sources

- https://vercel.com/changelog/fx-harness-adapter-now-separates-host-and-sandbox (primary, Vercel, published 2026-10-27)

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