Struct Meta 

pub struct Meta {
    pub progress_token: Option<ProgressToken>,
    pub cursor: Option<Cursor>,
    pub total: Option<u64>,
    pub has_more: Option<bool>,
    pub estimated_remaining_seconds: Option<f64>,
    pub progress: Option<f64>,
    pub current_step: Option<u64>,
    pub total_steps: Option<u64>,
    pub extra: HashMap<String, Value>,
}

Structured _meta field for MCP 2025-06-18

Fields

progress_token: Option<ProgressToken>

Progress token for tracking long-running operations

cursor: Option<Cursor>

Cursor for pagination

total: Option<u64>

Total number of items (for pagination context)

has_more: Option<bool>

Whether there are more items available

estimated_remaining_seconds: Option<f64>

Estimated remaining time in seconds

progress: Option<f64>

Current progress (0.0 to 1.0)

current_step: Option<u64>

Current step in a multi-step process

total_steps: Option<u64>

Total steps in a multi-step process

extra: HashMap<String, Value>

Additional metadata as key-value pairs

Implementations

impl Meta

pub fn new() -> Meta

Create a new empty Meta

pub fn with_progress_token(token: impl Into<ProgressToken>) -> Meta

Create Meta with progress token

pub fn with_cursor(cursor: impl Into<Cursor>) -> Meta

Create Meta with cursor for pagination

pub fn with_pagination( cursor: Option<Cursor>, total: Option<u64>, has_more: bool, ) -> Meta

Create Meta with pagination info

pub fn with_progress( progress: f64, current_step: Option<u64>, total_steps: Option<u64>, ) -> Meta

Create Meta with progress information

pub fn set_progress_token(self, token: impl Into<ProgressToken>) -> Meta

Add progress token

pub fn set_cursor(self, cursor: impl Into<Cursor>) -> Meta

Add cursor

pub fn set_pagination( self, cursor: Option<Cursor>, total: Option<u64>, has_more: bool, ) -> Meta

Set pagination info

pub fn set_progress( self, progress: f64, current_step: Option<u64>, total_steps: Option<u64>, ) -> Meta

Set progress info

pub fn set_estimated_remaining(self, seconds: f64) -> Meta

Set estimated remaining time

pub fn add_extra(self, key: impl Into<String>, value: impl Into<Value>) -> Meta

Add extra metadata

pub fn is_empty(&self) -> bool

Check if meta has any content

pub fn merge_request_extras( self, request_meta: Option<&HashMap<String, Value>>, ) -> Meta

Merge request extras from incoming request _meta into this Meta This helper preserves pagination context while adding request metadata

Trait Implementations

impl Clone for Meta

fn clone(&self) -> Meta

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Meta

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

Formats the value using the given formatter.

impl Default for Meta

fn default() -> Meta

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Meta

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Meta

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.