Tools

A tool is a named function with input and output schemas. Inputs are validated before execute runs, and outputs are validated before returning to the model, so every runtime boundary is typed.

Define a tool

import { defineTool } from '@fevex/core';
import { z } from 'zod';

const getAccount = defineTool({
  name: 'accounts_get',
  description: 'Get an account by ID.',
  inputSchema: z.object({ accountId: z.number() }),
  outputSchema: z.object({ accountId: z.number(), status: z.string() }),
  execute({ accountId }) {
    return { accountId, status: 'active' };
  },
});

Rules

• Tool names must match [A-Za-z0-9_-]{1,64}.
• Inputs are validated before execute; outputs are validated before they return to the model.
• Register tools in createFevex({ tools: [...] }) and reference them from an agent’s tools array by name.