Struct Session 

pub struct Session {
    pub id: String,
    pub client_info: Option<Implementation>,
    pub capabilities: Option<ClientCapabilities>,
    pub protocol_version: Option<String>,
    /* private fields */
}

Session represents a single MCP client connection

Fields

id: String

Unique session ID

client_info: Option<Implementation>

Client information (set during initialization)

capabilities: Option<ClientCapabilities>

Client capabilities (set during initialization)

protocol_version: Option<String>

Negotiated protocol version (set during initialization)

Implementations

impl Session

pub fn new() -> Self

Create new session with random UUID

pub fn with_id(id: impl Into<String>) -> Self

Create session with specific ID

pub fn initialize( &mut self, client_info: Implementation, capabilities: ClientCapabilities, protocol_version: String, )

Initialize session with client info and capabilities Transitions: Created -> Ready

pub fn set_notification_channel( &mut self, tx: UnboundedSender<JsonRpcNotification>, )

Set notification channel for this session

pub fn is_initialized(&self) -> bool

Check if session is initialized (Ready or Degraded)

pub fn protocol_version(&self) -> Option<&str>

Get the negotiated protocol version

pub fn record_error(&mut self)

Record an error, potentially transitioning to Degraded state Transitions: Ready -> Degraded (after threshold errors)

pub fn record_success(&mut self)

Record success, potentially recovering from Degraded state Transitions: Degraded -> Ready (resets error count)

pub fn close(&mut self)

Close the session Transitions: Any -> Closed

pub fn lifecycle(&self) -> SessionLifecycle

Get current lifecycle state

pub fn error_count(&self) -> u32

Get current error count

pub fn get_state(&self, key: &str) -> Option<Value>

Get state value

pub fn set_state(&self, key: impl Into<String>, value: Value)

Set state value

pub fn remove_state(&self, key: &str) -> Option<Value>

Remove state value

pub fn clear_state(&self)

Clear all state

pub fn state_keys(&self) -> Vec<String>

Get all state keys

pub fn add_tool(&self, tool: Arc<dyn Tool>)

Add an extra tool to this session

pub fn override_tool(&self, name: impl Into<String>, tool: Arc<dyn Tool>)

Override a tool (same name, different implementation)

pub fn hide_tool(&self, name: impl Into<String>, notify: bool)

Hide a tool from this session

If notify is true, sends a notifications/tools/list_changed notification.

pub fn unhide_tool(&self, name: &str, notify: bool)

Unhide a tool

If notify is true, sends a notifications/tools/list_changed notification.

pub fn alias_tool(&self, alias: impl Into<String>, target: impl Into<String>)

Add a tool alias (alias -> target)

pub fn remove_tool_alias(&self, alias: &str)

Remove a tool alias

pub fn is_tool_hidden(&self, name: &str) -> bool

Check if a tool is hidden

pub fn resolve_tool_alias<'a>(&self, name: &'a str) -> Cow<'a, str>

Resolve a tool alias to its target name

pub fn get_tool_override(&self, name: &str) -> Option<Arc<dyn Tool>>

Get a tool override for this session

pub fn get_tool_extra(&self, name: &str) -> Option<Arc<dyn Tool>>

Get an extra tool added to this session

pub fn tool_overrides(&self) -> &Arc<DashMap<String, Arc<dyn Tool>>>

Get all tool overrides

pub fn tool_extras(&self) -> &Arc<DashMap<String, Arc<dyn Tool>>>

Get all extra tools

pub fn remove_tool(&self, name: &str) -> Option<Arc<dyn Tool>>

Remove an extra tool from this session

pub fn remove_tool_override(&self, name: &str) -> Option<Arc<dyn Tool>>

Remove a tool override

pub fn add_resource(&self, resource: Arc<dyn Resource>)

Add an extra resource to this session

pub fn override_resource( &self, uri: impl Into<String>, resource: Arc<dyn Resource>, )

Override a resource (same URI, different implementation)

pub fn hide_resource(&self, uri: impl Into<String>)

Hide a resource from this session

pub fn unhide_resource(&self, uri: &str)

Unhide a resource

pub fn is_resource_hidden(&self, uri: &str) -> bool

Check if a resource is hidden

pub fn get_resource_override(&self, uri: &str) -> Option<Arc<dyn Resource>>

Get a resource override for this session

pub fn get_resource_extra(&self, uri: &str) -> Option<Arc<dyn Resource>>

Get an extra resource added to this session

pub fn resource_overrides(&self) -> &Arc<DashMap<String, Arc<dyn Resource>>>

Get all resource overrides

pub fn resource_extras(&self) -> &Arc<DashMap<String, Arc<dyn Resource>>>

Get all extra resources

pub fn remove_resource(&self, uri: &str) -> Option<Arc<dyn Resource>>

Remove an extra resource from this session

pub fn remove_resource_override(&self, uri: &str) -> Option<Arc<dyn Resource>>

Remove a resource override

pub fn add_prompt(&self, prompt: Arc<dyn Prompt>)

Add an extra prompt to this session

pub fn override_prompt(&self, name: impl Into<String>, prompt: Arc<dyn Prompt>)

Override a prompt (same name, different implementation)

pub fn hide_prompt(&self, name: impl Into<String>)

Hide a prompt from this session

pub fn unhide_prompt(&self, name: &str)

Unhide a prompt

pub fn is_prompt_hidden(&self, name: &str) -> bool

Check if a prompt is hidden

pub fn get_prompt_override(&self, name: &str) -> Option<Arc<dyn Prompt>>

Get a prompt override for this session

pub fn get_prompt_extra(&self, name: &str) -> Option<Arc<dyn Prompt>>

Get an extra prompt added to this session

pub fn prompt_overrides(&self) -> &Arc<DashMap<String, Arc<dyn Prompt>>>

Get all prompt overrides

pub fn prompt_extras(&self) -> &Arc<DashMap<String, Arc<dyn Prompt>>>

Get all extra prompts

pub fn remove_prompt(&self, name: &str) -> Option<Arc<dyn Prompt>>

Remove an extra prompt from this session

pub fn remove_prompt_override(&self, name: &str) -> Option<Arc<dyn Prompt>>

Remove a prompt override

pub fn batch<F>(&self, f: F)

where F: FnOnce(&mut SessionBatch<'_>),

Perform batch operations without sending notifications until complete

This allows you to make multiple changes and send a single notification.

Example

session.batch(|batch| {
    batch.add_tool(Arc::new(Tool1));
    batch.add_tool(Arc::new(Tool2));
    batch.remove_resource("old://resource");
    batch.hide_prompt("deprecated");
});
// Single notification sent after closure completes

pub fn apply_profile(&self, profile: &SessionProfile)

Apply a session profile

This adds/overrides/hides tools, resources, and prompts according to the profile

pub fn clear_customizations(&self)

Clear all session customizations

Trait Implementations

impl Clone for Session

fn clone(&self) -> Session

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Session

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

Formats the value using the given formatter.

impl Default for Session

fn default() -> Self

Returns the “default value” for a type.