theclaymethod / anthropic-zod-example

A simple example to get Claude to return a structured object, validated with zod

anthropic-zod-example

Why

OpenAI has begun offering a nicer developer experience around tools. Anthropic's function calling is much newer. This repo provides a basic example of setting up few helper functions to allow you to declare the function call via Zod, making it completely type safe.

This also includes a failover to try again with a more powerful model if the initial parse fails.

Run Instructions

copy .env.template to .env Add your Anthropic API Key

npm install
npm run example

This will enable easier configuration of functions, better validation, and full type safety when using tool calls

// Define the weather schema

const weatherParams = z.object({
    location: z.string().describe("The city and state, e.g. San Francisco, CA"),
    unit: z.enum(["celsius", "fahrenheit"]).optional().describe(
        "The unit of temperature, either 'celsius' or 'fahrenheit'",
    ),
})
type WeatherParams = z.infer<typeof weatherParams>;
const weatherSchema = {
    name: "get_weather",
    description: "Get the current weather in a given location",
    input_schema: weatherParams
};

// Example usage
const text = "What is the weather like in San Francisco?";
const result: WeatherParams = await parseTextToZodAnthropic<WeatherParams>({
    text,
    schema: weatherSchema,
});