TypeScript SDK

Installation

npm install veto-sdk

`Veto.init(options?)`

Initialize Veto. Loads configuration from ./veto by default.

import { Veto } from 'veto-sdk';

const veto = await Veto.init();

`veto.wrap<T>(tools: T[]): T[]`

Wraps an array of tools with validation. The returned tools have identical types — fully compatible with your AI framework.

const wrappedForLangChain = veto.wrap(langChainTools);
const wrappedForVercel = veto.wrap(vercelTools);

Works with LangChain, Vercel AI SDK, OpenAI function calling, Anthropic tool use, and custom tool objects.

`veto.wrapTool<T>(tool: T): T`

Wraps a single tool instance.

const safeTool = veto.wrapTool(myTool);

`veto.getHistoryStats()`

Returns statistics about validation decisions.

const stats = veto.getHistoryStats();
// { totalCalls: 5, allowedCalls: 4, deniedCalls: 1, ... }

`veto.clearHistory()`

Resets the history statistics.

veto.clearHistory();

Error handling

When a tool call is blocked, Veto throws a ToolCallDeniedError:

import { ToolCallDeniedError } from 'veto-sdk';

try {
  await wrappedTool.invoke(args);
} catch (error) {
  if (error instanceof ToolCallDeniedError) {
    console.log(error.message);  // "Tool call denied: limit-transfers"
    console.log(error.ruleId);   // "limit-transfers"
  }
}

Provider adapters

The SDK includes adapters that convert tool definitions between formats:

import { adapters } from 'veto-sdk/providers';

// Convert OpenAI tools to Anthropic format
const anthropicTools = adapters.toAnthropic(openAITools);

// Convert Anthropic tools to OpenAI format
const openAITools = adapters.toOpenAI(anthropicTools);

Exports

The SDK publishes multiple entry points:

Import	What it provides
`veto-sdk`	Core `Veto` class, types, errors
`veto-sdk/providers`	Provider adapters (OpenAI, Anthropic, Google)
`veto-sdk/rules`	Rule parsing and matching utilities
`veto-sdk/kernel`	Local model evaluation via Ollama
`veto-sdk/custom`	Direct LLM provider integration

On this page