Introducing Run SDK: secure eval for your agents
Run SDK executes agent-generated JavaScript or TypeScript behind narrow host functions, with resumable approval and auth boundaries instead of application-level eval access.
Vercel’s **Run SDK** executes JavaScript or type-stripped TypeScript in a fresh QuickJS context, isolated from Node.js and the network. Calls reach trusted application code only through declared host functions.
Use narrow, action-specific functions for agent tools, then interrupt sensitive calls for approval or authentication. A **signed resume token** restores the run while reusing results from host calls that already completed.
Vercel’s **Run SDK** executes JavaScript or type-stripped TypeScript in a fresh QuickJS context, isolated from Node.js and the network. Calls reach trusted application code only through declared host functions. Use narrow, action-specific functions for agent tools, then interrupt sensitive calls for approval or authentication. A **signed resume token** restores the run while reusing results from host calls that already completed. This is an application-level JavaScript sandbox, not an operating-system sandbox. Host functions remain trusted code and still require authorization checks; package installs and process isolation belong in Vercel Sandbox. Runtime support starts at **Node.js 22.13+** and Bun.
Run SDK introduces a narrow application-level boundary for executing agent-generated JavaScript and pausing sensitive host calls without repeating completed work. It confirms that useful agent evaluation can be separated from trusted application access, while sharply limiting the claim: host authorization, credential scope, network or process isolation, and broader policy enforcement remain external responsibilities.