Give a model a tool and let it decide when to call it.
flowchart LR Q([question]) --> A[Agent] A -- tool call --> T[multiply] T -- result --> A A --> R([answer])
maxIterations bounds the loop. output.toolCalls records every call.import { Agent } from '@astack-tech/components';
import { ModelProvider } from '@astack-tech/integrations';
import { createTool } from '@astack-tech/tools';
const apiKey = process.env['DEEPSEEK_API_KEY'];
if (!apiKey) {
throw new Error('Set DEEPSEEK_API_KEY to run this example.');
}
const multiply = createTool(
'multiply',
'Multiply two numbers.',
args => Number(args['a']) * Number(args['b']),
{
type: 'object',
properties: {
a: { type: 'number', description: 'First factor' },
b: { type: 'number', description: 'Second factor' },
},
required: ['a', 'b'],
}
);
// The agent asks the model, runs the tools it requests, and repeats until the model answers.
const agent = new Agent({
model: new ModelProvider.Deepseek({ apiKey }),
tools: [multiply],
systemPrompt: 'Use tools for arithmetic.',
maxIterations: 5,
});
const output = await agent.run('What is 37 times 43?');
console.log(output.message);
console.log(output.toolCalls);
// [ { tool: 'multiply', args: { a: 37, b: 43 }, result: 1591 } ]
pnpm install && pnpm build
export DEEPSEEK_API_KEY=sk-...
pnpm --filter @astack-examples/agent start