AI SDK 7.0.158 fixes partial JSON beginning with a negative number and expands experimental sandbox files
Released October 30, AI SDK 7.0.158 fixes streamed objects being reset to undefined when the first number in an array has only reached the valid prefix `[-`. Experimental `SandboxSession` also gains file status, directory listing and deletion APIs.
Why it matters
Generative interfaces often paint from partial JSON. Treating a valid negative-number prefix as invalid can make a rendered surface disappear or lose state. The sandbox additions bring file generation, inspection and cleanup into one runtime boundary.
A closer look
The regression fix covers `processUIMessageStream` input and UI-framework `useObject` paths with new tests. Experimental sandboxes add `stat`, `listDirectory` and `deleteFile`, specify relative-path, symlink and recursive-deletion behavior, and add live assertions across just-bash, Vercel Sandbox and Daytona adapters. The release also permits provider credentials to resolve asynchronously per request.
Who this is for
TypeScript teams building streamed generative interfaces, structured output, code workspaces and sandboxed agents with AI SDK
Original sources
- Vercel AI SDK official release and implementation commits ↗github.com
- Experimental sandbox filesystem operations and adapter assertions ↗github.com
- Partial JSON negative-number regression fix and tests ↗github.com
- Asynchronous provider credential resolution ↗github.com
Revisions & corrections (1)
— Publish a verified official patch that directly affects streamed generative-interface state and adds bounded experimental sandbox filesystem operations, with untested credential paths preserved as a limitation.