TL;DR
Vercel open-sources Run SDK, enabling safe execution of untrusted JavaScript/TypeScript with serialized host function boundaries and human-in-the-loop approval.
Key Points
- Executes untrusted code in isolated QuickJS contexts with no direct Node.js or network access
- Host functions provide narrow, serializable interfaces; sensitive operations can interrupt execution for approval
- Resumable execution replays programs but skips previously-completed host function calls, preserving state across interruptions
- Supports Node.js 22.13+ and Bun; powers code mode in Vercel's AI SDK for agent-generated workflows
Why It Matters
This solves a critical security problem for AI agent systems: safely executing generated code without exposing application secrets, credentials, or internal services. Developers can now build agent workflows that coordinate multiple services while maintaining fine-grained authorization boundaries and supporting approval workflows—essential for production AI applications handling sensitive operations.
Source: vercel.com