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. Each post paraphrases a public article and links to the original source.
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.
Keeping credentials in host functions, outside the sandbox, fits the Node server work in Chapter 5 and the Next.js app in Chapter 1.
Read original: Introducing Run SDK: secure eval for your agents — Vercel