Struct StringSchema 

#[non_exhaustive]
pub struct StringSchema {
    pub type_: StringTypeConst,
    pub title: Option<Cow<'static, str>>,
    pub description: Option<Cow<'static, str>>,
    pub min_length: Option<u32>,
    pub max_length: Option<u32>,
    pub format: Option<StringFormat>,
    pub default: Option<String>,
}

Available on crate features mcp and tools only.

Schema definition for string properties.

Compliant with MCP 2025-06-18 specification for elicitation schemas. Supports only the fields allowed by the MCP spec:

• format limited to: “email”, “uri”, “date”, “date-time”

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

type_: StringTypeConst

Type discriminator

title: Option<Cow<'static, str>>

Optional title for the schema

description: Option<Cow<'static, str>>

Human-readable description

min_length: Option<u32>

Minimum string length

max_length: Option<u32>

Maximum string length

format: Option<StringFormat>

String format - limited to: “email”, “uri”, “date”, “date-time”

default: Option<String>

Default value

Implementations

impl StringSchema

pub fn new() -> StringSchema

Create a new string schema

pub fn email() -> StringSchema

Create an email string schema

pub fn uri() -> StringSchema

Create a URI string schema

pub fn date() -> StringSchema

Create a date string schema

pub fn date_time() -> StringSchema

Create a date-time string schema

pub fn title(self, title: impl Into<Cow<'static, str>>) -> StringSchema

Set title

pub fn description( self, description: impl Into<Cow<'static, str>>, ) -> StringSchema

Set description

pub fn with_length( self, min: u32, max: u32, ) -> Result<StringSchema, &'static str>

Set minimum and maximum length

pub fn length(self, min: u32, max: u32) -> StringSchema

Set minimum and maximum length (panics on invalid input)

pub fn min_length(self, min: u32) -> StringSchema

Set minimum length

pub fn max_length(self, max: u32) -> StringSchema

Set maximum length

pub fn format(self, format: StringFormat) -> StringSchema

Set format (limited to: “email”, “uri”, “date”, “date-time”)

pub fn with_default(self, default: impl Into<String>) -> StringSchema

Set default value

Trait Implementations

impl Clone for StringSchema

fn clone(&self) -> StringSchema

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for StringSchema

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for StringSchema

fn default() -> StringSchema

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for StringSchema

fn deserialize<__D>( __deserializer: __D, ) -> Result<StringSchema, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl JsonSchema for StringSchema

fn schema_name() -> Cow<'static, str>

The name of the generated JSON Schema.

fn schema_id() -> Cow<'static, str>

Returns a string that uniquely identifies the schema produced by this type.

fn json_schema(generator: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn inline_schema() -> bool

Whether JSON Schemas generated for this type should be included directly in parent schemas, rather than being re-used where possible using the $ref keyword.

impl PartialEq for StringSchema

fn eq(&self, other: &StringSchema) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for StringSchema

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for StringSchema