Deterministic guardrails
for autonomous agents

import { chromium } from 'playwright'
import { Veto } from 'veto'
const browser = await chromium.launch()
const page = await browser.newPage()
const tools = [
  {
    type: 'function',
    function: {
      name: 'browser_navigate',
      description: 'Navigate to a URL',
      parameters: {
        type: 'object',
        properties: {
          url: { type: 'string' }
        },
        required: ['url']
      }
    }
  },
  {
    type: 'function',
    function: {
      name: 'browser_click',
      description: 'Click a selector',
      parameters: {
        type: 'object',
        properties: {
          selector: { type: 'string' }
        },
        required: ['selector']
      }
    }
  }
]
const toolHandlers = {
  browser_navigate: async ({ url }: { url: string }) = page.goto(url),
  browser_click: async ({ selector }: { selector: string }) = page.click(selector)
}
const veto = await Veto.init()
const wrappedTools = veto.wrap(tools)
await agent.run('Book a flight under $400', { tools: wrappedTools, toolHandlers })