AI SDK passes abortSignal to the tool's execute, but the bash tool drops it before calling the sandbox. Even an already-aborted signal lets echo changed > evidence.txt overwrite the file.
This forwards the signal through Sandbox.executeCommand to just-bash and Vercel's command/output calls. The new options argument is optional, so existing custom sandboxes still work.
Cancellation still depends on the backend. just-bash needs a version with signal support; Vercel can abort the request/wait without stopping the remote process.
The regression test checks that an already-aborted command leaves the file unchanged, for both default and supplied just-bash instances. The Vercel adapter test checks signal forwarding. All three cases fail before the fix and pass after it.
pnpm validate passes (155 tests). Live Vercel execution wasn't tested.