Messages API

const message = await client.messages.create({
  model: process.env.ANTHROPIC_MODEL ?? "claude-sonnet-4-5",
  max_tokens: 512,
  system: "You are a careful support agent.",
  messages: [
    {
      role: "user",
      content: "Summarize password reset link expiration guidance.",
    },
  ],
});

const messages: Anthropic.Messages.MessageParam[] = [
  {
    role: "user",
    content: "Search the docs for password reset guidance.",
  },
];

let response = await client.messages.create({
  model: process.env.ANTHROPIC_MODEL ?? "claude-sonnet-4-5",
  max_tokens: 1024,
  system: "You are a careful support agent. Use tools when they help.",
  messages,
  tools,
});

const toolUses = response.content.filter((block) => block.type === "tool_use");

if (toolUses.length > 0) {
  messages.push({
    role: "assistant",
    content: response.content,
  });

  messages.push({
    role: "user",
    content: toolUses.map((toolUse) => ({
      type: "tool_result",
      tool_use_id: toolUse.id,
      content: JSON.stringify({
        matches: ["Password reset links expire after 24 hours."],
      }),
    })),
  });

  response = await client.messages.create({
    model: process.env.ANTHROPIC_MODEL ?? "claude-sonnet-4-5",
    max_tokens: 1024,
    system: "You are a careful support agent. Use tools when they help.",
    messages,
    tools,
  });
}

client = wrapAnthropic(client, {
  onDecision(event) {
    console.log(event.checkpointType, event.decision.decision);
  },
});