Struct RequestMeta 

pub struct RequestMeta {
    pub version: ProtocolVersion,
    pub capabilities: CapabilitySet,
    pub client_name: Option<String>,
    pub log_level: Option<LogLevel>,
}

What one request said about itself.

capabilities and version are not optional because the schema does not make them so: both are in RequestMetaObject’s required. A request that omits either is refused by RequestMeta::read rather than served with a default, because a default here would be the server inventing a capability the client never claimed.

Fields

version: ProtocolVersion

The revision this request is written against.

capabilities: CapabilitySet

What the client supports, read through the shared capability tables.

client_name: Option<String>

The client’s self-reported name, when it sent one.

A SHOULD in the SEP and self-reported by the definition: nothing in this crate’s answers depends on it, and a server that trusted it would be trusting a string the schema calls unverified.

log_level: Option<LogLevel>

The level this request opted in to log records at, or None for none.

Implementations

impl RequestMeta

pub fn read(params: &JsonObject) -> Result<Self, RequestMetaError>

Reads the block off a request’s params.

Errors

RequestMetaError for each of the faults above, distinguished as documented on the type.

Examples

use protocol_droid::application::mcp::request_meta::{RequestMeta, RequestMetaError};
use protocol_droid::domain::ir::JsonObject;
use protocol_droid::domain::{Capability, ProtocolVersion};

// One line, because the keys are long and rustfmt would otherwise
// break the literal across lines — and `JsonObject` validates on
// construction, so a newline inside the JSON is a parse error.
let params = JsonObject::new(
    r#"{"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientCapabilities":{"roots":{}},"io.modelcontextprotocol/clientInfo":{"name":"probe","version":"1"}}}"#,
)?;

let meta = RequestMeta::read(&params)?;
assert_eq!(meta.version, ProtocolVersion::V2026_07_28);
assert!(meta.capabilities.contains(Capability::Roots));
assert_eq!(meta.client_name.as_deref(), Some("probe"));

// A request with no `_meta` is an older revision, not a fault.
let older = JsonObject::new(r#"{"method":"tools/list"}"#)?;
assert_eq!(RequestMeta::read(&older).err(), Some(RequestMetaError::Absent));

Trait Implementations

impl Clone for RequestMeta

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RequestMeta

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

Formats the value using the given formatter.

impl Eq for RequestMeta

impl PartialEq for RequestMeta

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for RequestMeta