tools.ts

#!/usr/bin/env -S npm run tsn -T

import Anthropic from '@anthropic-ai/sdk';
import assert from 'node:assert';

const client = new Anthropic(); // gets API Key from environment variable ANTHROPIC_API_KEY

async function main() {
  const userMessage: Anthropic.MessageParam = {
    role: 'user',
    content: 'What is the weather in SF?',
  };
  const tools: Anthropic.Tool[] = [
    {
      name: 'get_weather',
      description: 'Get the weather for a specific location',
      input_schema: {
        type: 'object',
        properties: { location: { type: 'string' } },
      },
    },
  ];

  const message = await client.messages.create({
    model: 'claude-3-5-sonnet-latest',
    max_tokens: 1024,
    messages: [userMessage],
    tools,
  });
  console.log('Initial response:');
  console.dir(message, { depth: 4 });

  assert(message.stop_reason === 'tool_use');

  const tool = message.content.find(
    (content): content is Anthropic.ToolUseBlock => content.type === 'tool_use',
  );
  assert(tool);

  const result = await client.messages.create({
    model: 'claude-3-5-sonnet-latest',
    max_tokens: 1024,
    messages: [
      userMessage,
      { role: message.role, content: message.content },
      {
        role: 'user',
        content: [
          {
            type: 'tool_result',
            tool_use_id: tool.id,
            content: [{ type: 'text', text: 'The weather is 73f' }],
          },
        ],
      },
    ],
    tools,
  });
  console.log('\nFinal response');
  console.dir(result, { depth: 4 });
}

main();