Attributes Reference

The #[zod(...)] attribute configures validation constraints on struct fields.

String attributes

Attribute	Description	Example
min_length(n)	Minimum string length	#[zod(min_length(3))]
max_length(n)	Maximum string length	#[zod(max_length(50))]
length(n)	Exact string length	#[zod(length(2))]
email	Email format	#[zod(email)]
url	URL format	#[zod(url)]
regex("pattern")	Regex pattern	#[zod(regex(r"^[a-z]+$"))]
starts_with("value")	Starts with prefix	#[zod(starts_with("hello"))]
ends_with("value")	Ends with suffix	#[zod(ends_with("@domain.com"))]
includes("value")	Contains substring	#[zod(includes("test"))]

Number attributes

Attribute	Description	Example
min(n)	Minimum value	#[zod(min(0.0))]
max(n)	Maximum value	#[zod(max(100.0))]
int	Integer only	#[zod(int)]
positive	Must be > 0	#[zod(positive)]
negative	Must be < 0	#[zod(negative)]
nonnegative	Must be >= 0	#[zod(nonnegative)]
nonpositive	Must be <= 0	#[zod(nonpositive)]
finite	Must be finite	#[zod(finite)]

Array attributes

Attribute	Description	Example
min_length(n)	Minimum array length	#[zod(min_length(1))]
max_length(n)	Maximum array length	#[zod(max_length(10))]
length(n)	Exact array length	#[zod(length(3))]

Combining attributes

Multiple attributes can be combined in a single #[zod(...)]:

#[derive(ZodSchema)]
struct Registration {
    #[zod(min_length(3), max_length(20), regex(r"^[a-zA-Z0-9_]+$"))]
    username: String,

    #[zod(min(13.0), max(120.0), int)]
    age: u32,

    #[zod(min_length(1), max_length(5))]
    tags: Vec<String>,
}

Fields without attributes

Fields without #[zod(...)] attributes use the default schema for their type:

#[derive(ZodSchema)]
struct Simple {
    name: String,      // string() — no extra validation
    count: u32,        // number().int()
    active: bool,      // boolean()
    items: Vec<String>, // array(string())
    bio: Option<String>, // optional(string())
}