Validation Types

The A2A SDK provides comprehensive validation capabilities through Zod. This page documents the available validation types and their usage.

Primitive Types

Strings

z.string() // Basic string
  .min(5) // Minimum length
  .max(100) // Maximum length
  .email() // Valid email format
  .url() // Valid URL format
  .uuid() // Valid UUID
  .regex(/^[a-z]+$/) // Custom regex

Numbers

z.number() // Basic number
  .int() // Integer only
  .positive() // > 0
  .nonnegative() // >= 0
  .min(5) // Minimum value
  .max(100) // Maximum value

Booleans

z.boolean() // true or false

Dates

z.date() // Date object
  .min(new Date('2020-01-01')) // Minimum date
  .max(new Date()) // Maximum date (now)

Complex Types

Objects

z.object({
  name: z.string(),
  age: z.number().int().positive(),
  address: z.object({
    street: z.string(),
    city: z.string()
  }).optional()
})

Arrays

z.array(z.string()) // Array of strings
  .min(1) // Minimum length
  .max(10) // Maximum length
  .nonempty() // At least one item

Unions

z.union([
  z.string(),
  z.number()
])
 
// Alternative syntax:
z.string().or(z.number())

Records

z.record(z.string()) // { [key: string]: string }
z.record(z.string(), z.number()) // { [key: string]: number }

Special Types

Literals

z.literal('success') // Exact value match
z.literal(42)
z.literal(true)

Enums

z.enum(['pending', 'completed', 'failed'])
 
// Or from a TypeScript enum:
enum Status {
  Pending = 'pending',
  Completed = 'completed'
}
z.nativeEnum(Status)

Optionals & Nullables

z.string().optional() // string | undefined
z.string().nullable() // string | null
z.string().nullish() // string | null | undefined

Next Steps

Schemas Utilities