What is Veto?

Veto is the machine authority runtime for agent actions. Agents often have technical capability to call tools, reach APIs, and change systems. Veto answers the separate authority question: what may this machine action do, under which artifact, with which constraints, approval, expiry, and receipt?

TypeScript in one minute

npm install veto-sdk

import { protect } from "veto-sdk";

const tools = await protect([
  {
    name: "issue_refund",
    execute: async ({ amount_usd }: { amount_usd: number }) => {
      return { refunded: amount_usd };
    },
  },
]);

What Veto Gives You

• MAP artifacts: portable authority objects with subject, action, resource, constraints, approval, expiry, and receipt fields.
• Local runtime: deterministic evaluation by default, with no account, API key, or network needed for the core decision.
• Approval binding: human approval is bound to the exact action hash and policy hash, so mismatched approvals fail closed.
• Receipts: offline-verifiable records that bind action, policy, approval, previous receipt, and issued-at time.
• Authoring surfaces: LLM drafting may propose artifacts for human review; it is not in the authority decision path.
• Adapters: existing authorization, policy, and governance tools can be wrapped into MAP receipts without making Veto an IAM system.

Current SDK Surfaces

Next Steps