Enum JSON Format

zod-rs uses serde’s default externally-tagged format for enums. Here’s how each variant type maps to JSON.

Format table

Variant Type	Rust	JSON
Unit	Status::Active	"Active"
Tuple (single)	Message::Text("hi")	{"Text": "hi"}
Tuple (multiple)	Message::Coords(1, 2)	{"Coords": [1, 2]}
Struct	Event::Click { x: 1, y: 2 }	{"Click": {"x": 1, "y": 2}}

Unit variants

Unit variants serialize as plain strings:

#[derive(Serialize, Deserialize, ZodSchema)]
enum Status { Active, Inactive }

// JSON: "Active"

The legacy {"Active": null} form is also accepted during validation, matching serde’s deserialization behavior.

Tuple variants (single)

Single-value tuple variants unwrap the value:

#[derive(Serialize, Deserialize, ZodSchema)]
enum Msg { Text(String) }

// JSON: {"Text": "hello"}

Tuple variants (multiple)

Multi-value tuple variants use an array:

#[derive(Serialize, Deserialize, ZodSchema)]
enum Msg { Coords(i32, i32) }

// JSON: {"Coords": [10, 20]}

Struct variants

Struct variants use a nested object:

#[derive(Serialize, Deserialize, ZodSchema)]
enum Event { Click { x: i32, y: i32 } }

// JSON: {"Click": {"x": 1, "y": 2}}

Validation

Each variant is validated as a union. Unit variants match their string name; variants with data must be a single-key object where the key matches the variant name and the value matches that variant’s expected format.

Serde renames

#[serde(rename = "...")] on variants and #[serde(rename_all = "...")] on the enum are honored, so the validated names always match what serde accepts:

#[derive(Serialize, Deserialize, ZodSchema)]
#[serde(rename_all = "snake_case")]
enum Example { SomeValue, AnotherValue }

// JSON: "some_value", "another_value"

#[derive(Serialize, Deserialize, ZodSchema)]
enum AccountVerificationType {
    #[serde(rename = "register")]
    Register,
    #[serde(rename = "login")]
    Login,
}

// JSON: "register", "login"