Khoury College of Computer Sciences
CS 4550 / CS 5610 · Web Development · Fall 2026
Vercel Run SDK: sandboxed JavaScript for agent-generated code
- AI
- Security
- Course
Instructor-curated digest, not original reporting. Optional further reading — not required for grades.
On August 25, 2026, Aayush Kapoor published Introducing Run SDK on the Vercel blog. The package runs untrusted JavaScript or type-stripped TypeScript in a fresh QuickJS context inside a worker thread, with no direct route to Node.js or the network. Applications expose narrow hostFunctions that become callable globals inside the sandbox; credentials and service clients stay in the host.
Host functions can interrupt a run for human approval or authentication via getHostFunctionContext().interrupt, then resume with a signed token so settled host calls are not repeated. createRunner() sets shared limits such as timeoutMs and memoryLimitBytes. The post states the Run SDK powers code-mode tool execution in the AI SDK, supports Node.js 22.13+ and Bun (install with pnpm add run), and that OS-level isolation still belongs in Vercel Sandbox rather than this in-process QuickJS boundary.
Optional further reading for CS 4550 / CS 5610 — not required for labs or grades. For Chapter 5 server work and any agent features that eval generated code, the lesson is to keep secrets out of the sandbox and authorize inside host functions. Follow the original post for API details.
Read original: Introducing Run SDK: secure eval for your agents — Vercel