Struct Session 

pub struct Session {

    pub input: String,
    pub output_lines: Vec<String>,
    pub workflow_tx: UnboundedSender<TuiMessage>,
    pub workflow_state: WorkflowState,
    pub config_toml: Option<String>,
    pub secrets: Option<HashMap<String, String>>,
    pub build_info: Option<BuildInfo>,
    pub resume_info: Option<ResumeInfo>,
    pub backup_resume_info: Option<ResumeInfo>,
    pub todo_lines: Vec<String>,
    pub cancel_token: CancellationToken,
    pub pending_command: Option<String>,
    pub handoff_pending: bool,
    pub pending_tool_lines: Vec<(String, usize, Option<String>)>,
    pub current_context_tokens: usize,
    pub auto_handoff: AutoHandoffConfig,
    pub mcp_servers: Vec<McpServerInfo>,
    pub should_quit: bool,
    pub auto_scroll: bool,
    pub agent_name: String,
    pub token_store: Option<Arc<dyn TokenStore>>,
    pub project_id: Option<String>,
    pub project_name: Option<String>,
    pub session_id: Option<String>,
    pub session_name: Option<String>,
    pub home_dir: Option<PathBuf>,
    pub workflow_permit: Option<OwnedSemaphorePermit>,
}

Core session state for the Trustee agent.

Holds all state that is independent of the presentation layer (TUI, API, Web). Frontend crates compose this struct and add their own UI-specific fields.

Fields

input: String

Input buffer for user commands

output_lines: Vec<String>

Output log lines

workflow_tx: UnboundedSender<TuiMessage>

Sender for messages from async workflows (clone and pass to workflow runners)

workflow_state: WorkflowState

Current workflow lifecycle state

config_toml: Option<String>

Configuration TOML for ABK workflows

secrets: Option<HashMap<String, String>>

Secrets for ABK workflows

build_info: Option<BuildInfo>

Build info for ABK workflows

resume_info: Option<ResumeInfo>

Resume info from the last completed task for session continuity

backup_resume_info: Option<ResumeInfo>

Saved resume_info before execute_command consumes it; restored if task is cancelled before producing a real checkpoint (mistake-ENTER recovery).

todo_lines: Vec<String>

Latest todo list from LLM todowrite tool

cancel_token: CancellationToken

Cancellation token for aborting the current workflow

pending_command: Option<String>

Command buffered by user during cancellation wind-down.

handoff_pending: bool

Whether a session handoff (Ctrl+H) should fire once the current workflow cancels.

pending_tool_lines: Vec<(String, usize, Option<String>)>

In-flight spinner entries: (tool_name, output_lines_index, hint).

current_context_tokens: usize

Current context token count (updated from ApiCallStarted events).

auto_handoff: AutoHandoffConfig

Auto-handoff configuration parsed from [tui.auto_handoff].

mcp_servers: Vec<McpServerInfo>

MCP server statuses received from agent init

should_quit: bool

Whether the session should quit

auto_scroll: bool

Whether auto-scroll is enabled (follows new output)

agent_name: String

Agent name for checkpoint/token paths (replaces ABK_AGENT_NAME env var). Defaults to “trustee”. Set from config at startup.

token_store: Option<Arc<dyn TokenStore>>

Per-session token store (None = FileTokenStore fallback). When set, MCP credential flows use this instead of file-based storage.

project_id: Option<String>

Storage partition key (replaces path hash). None = hash(working_dir)

project_name: Option<String>

Human-readable project name. None = directory name

session_id: Option<String>

Storage directory name (replaces timestamp slug). None = auto-generate

session_name: Option<String>

Human-readable session name. None = no description

home_dir: Option<PathBuf>

Per-user home directory for checkpoint storage. None = default ~/.{agent_name}/ Set to ~/.trustee/users/{user_hash}/ for per-user isolation in web mode.

workflow_permit: Option<OwnedSemaphorePermit>

Concurrency permit — held while a workflow is running. When the workflow completes (state → Idle), this is dropped, releasing the permit back to the global semaphore. None when no workflow is running or when concurrency limiting is disabled.

Implementations

impl Session

pub fn new() -> (Self, UnboundedReceiver<TuiMessage>)

Create a new Session with default state and a fresh message channel.

Returns (Session, Receiver) so the caller can own the receiver without locking the session (prevents deadlock in async drain loops).

pub fn parse_auto_handoff_config(&mut self)

Parse auto-handoff configuration from the stored config TOML.

pub fn handle_workflow_message(&mut self, msg: TuiMessage)

Handle messages from async workflows.

This processes all workflow lifecycle events, output updates, and state transitions. Returns true if the caller should check for pending commands/handoffs after.

pub fn execute_command(&mut self)

Execute the current command in the input buffer.

Spawns an async ABK workflow task, clears the input buffer, and sets workflow_state to Running.

pub fn trigger_handoff(&mut self, hint: String)

Trigger a session handoff.

Runs a single LLM call using the current session’s resume_info to generate a briefing. On completion, sends TuiMessage::HandoffReady(briefing).

Trait Implementations

impl Default for Session

fn default() -> Self

Returns the “default value” for a type.