Built-in Tools

easy5 minbuilt-in-tools.ts

You need an analyst that reads files and does exact math instead of guessing, without writing the tools yourself.

What it shows

Use calculator, datetime, fileRead, fileList and regexMatch from @cogitator-ai/core
Let the agent chain several tool calls in one run

The code

built-in-tools.ts

import { Agent, Cogitator, calculator, datetime, fileList, fileRead, regexMatch } from '@cogitator-ai/core';
import { mkdirSync, writeFileSync } from 'node:fs';
import { join } from 'node:path';

const apiKey = process.env.GOOGLE_API_KEY;
if (!apiKey) throw new Error('Set GOOGLE_API_KEY');

const dataDir = join(process.cwd(), 'sales-data');
mkdirSync(dataDir, { recursive: true });
writeFileSync(
  join(dataDir, 'sales-q4.csv'),
  [
    'date,product,quantity,price',
    '2025-10-01,Widget A,150,29.99',
    '2025-11-01,Widget A,200,29.99',
    '2025-11-20,Widget C,45,99.99',
    '2025-12-18,Widget A,300,29.99',
  ].join('\n')
);

const cog = new Cogitator({ llm: { providers: { google: { apiKey } } } });

const analyst = new Agent({
  name: 'analyst',
  model: 'google/gemini-3.5-flash-lite',
  instructions: `You are a data analyst with filesystem, calculator, datetime and regex tools.
Read files first, use the calculator for math and regex for pattern extraction.`,
  tools: [calculator, datetime, fileRead, fileList, regexMatch],
  temperature: 0.2,
  maxIterations: 15,
});

const revenue = await cog.run(analyst, {
  input: `Read ${join(dataDir, 'sales-q4.csv')} and calculate the total revenue for Widget A.`,
});
console.log(revenue.output);

const november = await cog.run(analyst, {
  input: `Read ${join(dataDir, 'sales-q4.csv')} and use regex to count the November (2025-11-xx) rows.`,
});
console.log(november.output);
console.log('Tools used:', november.toolCalls.map((call) => call.name).join(', '));

await cog.close();

Run it

install · bash

pnpm add @cogitator-ai/core

EnvironmentGOOGLE_API_KEY

run · bash

GOOGLE_API_KEY=your-key npx tsx built-in-tools.ts

Or run the full example from a clone of the repository (keys in .env):

repository · bash

npx tsx examples/core/02-built-in-tools.ts

Built-in Tools

What it shows

The code

Run it

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