การผสานรวม Zod ในกระบวนงาน tRPC

Welcome! In this lesson, we'll learn how to integrate Zod schemas directly into your tRPC procedures. This powerful combination ensures your API inputs are always valid and type-safe from end-to-end.

You'll see how to apply Zod for both query and mutation procedures, making your backend more robust and developer-friendly.

Input validation is a critical part of building secure and reliable APIs. It's like a quality check at the entrance of your backend.

• Security: Prevents malicious or malformed data from reaching your server logic.
• Data Integrity: Ensures your database only stores valid and expected data formats.
• Predictability: Your backend logic can trust the shape of incoming data, reducing runtime errors.
• Better DX: Developers get immediate feedback on incorrect inputs.

tRPC makes integrating Zod incredibly simple. Each tRPC procedure (query, mutation, or subscription) has an .input() method.

This method accepts a Zod schema, which tRPC then uses to automatically validate any incoming data for that procedure. If the input doesn't match the schema, tRPC handles the error for you!

For queries, you often expect parameters like an ID or a search term. Zod helps ensure these inputs are of the correct type and format.

Let's look at an example where we want to fetch a user by their unique ID. We'll use Zod to ensure the userId is a valid UUID string.

Here's how you define a tRPC query procedure that uses a Zod schema to validate its input:

Mutations often involve creating or updating data, which means they typically accept more complex input objects. Zod is perfect for validating these structures.

Consider a scenario where you want to create a new blog post. We'll validate its title and optional content to ensure they meet certain criteria.

Here's a mutation procedure that validates input for creating a new post using a Zod object schema:

One of the biggest advantages of integrating Zod directly with tRPC is automatic error handling.

• If a client sends input that doesn't match your Zod schema, tRPC will automatically catch the validation error.
• It then sends a standardized BAD_REQUEST error response to the client, including details about why the validation failed.
• This means you don't need to write manual try/catch blocks for basic input validation!

Combining Zod with tRPC's .input() method provides several powerful benefits:

• End-to-End Type Safety: Your Zod schema defines the exact input type, which tRPC automatically infers and shares with your client.
• Single Source of Truth: Define validation rules once, and they apply on both the server (runtime) and client (compile-time).
• Reduced Boilerplate: No need for manual validation checks or separate DTOs (Data Transfer Objects).
• Clear API Contracts: Your procedures clearly state their input requirements through their Zod schemas.

Great job! You've successfully learned how to integrate Zod schemas into your tRPC procedures.

• We saw that the .input() method is key for applying Zod schemas to both queries and mutations.
• This integration provides automatic validation, end-to-end type safety, and clear API contracts.
• By leveraging Zod within tRPC, you build more robust, secure, and developer-friendly APIs with less effort.

Next up, we'll explore more advanced Zod schemas!