Struct SessionState 

pub struct SessionState {
    pub summary: SessionSummary,
    pub lifecycle: SessionLifecycle,
    pub creation_error: Option<ErrorInfo>,
    pub server_tools: Option<Vec<ToolDefinition>>,
    pub active_client: Option<SessionActiveClient>,
    pub chats: Vec<ChatSummary>,
    pub default_chat: Option<Uri>,
    pub config: Option<SessionConfigState>,
    pub customizations: Option<Vec<Customization>>,
    pub changesets: Option<Vec<Changeset>>,
    pub meta: Option<JsonObject>,
}

Full state for a single session, loaded when a client subscribes to the session’s URI.

Fields

summary: SessionSummary

Lightweight session metadata

lifecycle: SessionLifecycle

Session initialization state

creation_error: Option<ErrorInfo>

Error details if creation failed

server_tools: Option<Vec<ToolDefinition>>

Tools provided by the server (agent host) for this session

active_client: Option<SessionActiveClient>

The client currently providing tools and interactive capabilities to this session

chats: Vec<ChatSummary>

Catalog of chats in this session.

default_chat: Option<Uri>

The chat that receives input when the user addresses the session without selecting a specific chat. This is a UI routing hint, not a hierarchy marker — chats remain equal peers at the protocol level. Hosts MAY change this over the session’s lifetime.

config: Option<SessionConfigState>

Session configuration schema and current values

customizations: Option<Vec<Customization>>

Top-level customizations active in this session.

Always one of the {@link Customization} variants:

• Container customizations ({@link PluginCustomization}, {@link DirectoryCustomization}) whose children — agents, skills, prompts, rules, hooks, MCP servers — live in each container’s {@link ContainerCustomizationBase.children | children} array.
• Top-level {@link McpServerCustomization} entries the host surfaces directly (for example a globally-configured MCP server that isn’t bundled in a plugin or directory). MCP servers may also appear as children of a container.

Client-published plugins arrive via {@link SessionActiveClient.customizations | activeClient.customizations} and the host propagates them into this list (typically with the container’s clientId set and children populated). Clients publish in container shape only; bare MCP servers at the top level are server-originated.

changesets: Option<Vec<Changeset>>

Catalogue of changesets the server can produce for this session. Each entry advertises a subscribable view of file changes (uncommitted, session-wide, per-turn, etc.) and the URI template the client expands before subscribing. See {@link Changeset} for the full shape and {@link /guide/changesets | Changesets} for an overview of the model.

meta: Option<JsonObject>

Additional provider-specific metadata for this session.

Clients MAY look for well-known keys here to provide enhanced UI. For example, a git key may provide extra git metadata about the session’s workingDirectory.

Trait Implementations

impl Clone for SessionState

fn clone(&self) -> SessionState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SessionState

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for SessionState

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for SessionState

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for SessionState

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for SessionState