API ReferencevalidationIndex

Validation Overview

The A2A Node SDK uses Zod for runtime validation of messages, tasks, and other protocol objects. This section documents the validation utilities available.

Basic Usage

import { z } from '@a2a/sdk';
 
// Create a schema
const taskSchema = z.object({
  id: z.string(),
  name: z.string().min(1),
  status: z.enum(['pending', 'running', 'completed']),
  createdAt: z.date()
});
 
// Validate data
const result = taskSchema.safeParse(input);
if (result.success) {
  // Type-safe access to validated data
  const task = result.data;
} else {
  // Handle validation errors
  console.error(result.error);
}

Validation Types

  • Primitives: Strings, numbers, booleans, dates
  • Objects: Nested structures with type checking
  • Arrays: Typed collections with length constraints
  • Unions: Alternative valid types
  • Custom: Extend with your own validators

Common Patterns

Message Validation

const messageSchema = z.object({
  type: z.literal('task_update'),
  payload: z.object({
    taskId: z.string(),
    status: z.enum(['started', 'progress', 'completed'])
  })
});

Task Validation

const taskInputSchema = z.object({
  name: z.string().min(3),
  parameters: z.record(z.string(), z.unknown()),
  timeout: z.number().positive().optional()
});

Next Steps

z.ZodFirstPartyTypeKindMethods