Struct Session 

pub struct Session {

    pub model: String,
    pub reasoning_effort: Option<String>,
    pub reasoning_effort_auto: bool,
    pub auto_model: bool,
    pub workspace: PathBuf,
    pub system_prompt: Option<SystemPrompt>,
    pub last_system_prompt_hash: Option<u64>,
    pub compaction_summary_prompt: Option<SystemPrompt>,
    pub messages: Vec<Message>,
    pub total_usage: SessionUsage,
    pub allow_shell: bool,
    pub trust_mode: bool,
    pub auto_approve: bool,
    pub approval_mode: ApprovalMode,
    pub notes_path: PathBuf,
    pub mcp_config_path: PathBuf,
    pub id: String,
    pub project_context: Option<ProjectContext>,
    pub working_set: WorkingSet,
    pub cycle_count: u32,
    pub current_cycle_started: DateTime<Utc>,
    pub cycle_briefings: Vec<CycleBriefing>,
    pub last_api_input_tokens: Option<u32>,
    pub temperature: Option<f32>,
    pub top_p: Option<f32>,
    pub max_output_tokens: Option<u32>,
}

Session state for the engine.

Fields

model: String

Model being used

reasoning_effort: Option<String>

Reasoning-effort tier for DeepSeek thinking mode: "off" | "low" | "medium" | "high" | "max". None lets the provider apply its own defaults.

reasoning_effort_auto: bool

Whether the user selected automatic reasoning effort.

auto_model: bool

Whether the user selected automatic model routing.

workspace: PathBuf

Workspace directory

system_prompt: Option<SystemPrompt>

System prompt (optional)

last_system_prompt_hash: Option<u64>

Hash of the last assembled stable system prompt. Used to avoid replacing system_prompt when unchanged.

compaction_summary_prompt: Option<SystemPrompt>

Persisted summary blocks generated by context compaction.

messages: Vec<Message>

Conversation history (API format)

total_usage: SessionUsage

Total tokens used in this session

allow_shell: bool

Whether shell execution is allowed

trust_mode: bool

Whether to trust paths outside workspace

auto_approve: bool

Whether the current session should auto-approve tool safety checks.

approval_mode: ApprovalMode

Live UI approval policy used to steer the system prompt.

notes_path: PathBuf

Notes file path

mcp_config_path: PathBuf

MCP config path

id: String

Session ID (for tracking)

project_context: Option<ProjectContext>

Project context loaded from AGENTS.md, etc.

working_set: WorkingSet

Repo-aware working set for context management.

cycle_count: u32

Number of cycle boundaries crossed in this session (issue #124). The active cycle index is cycle_count + 1 (cycles are 1-based for users).

current_cycle_started: DateTime<Utc>

UTC start time of the current cycle. Updated when the engine resets the conversation buffer. Used by archive headers and the /cycles command’s display.

cycle_briefings: Vec<CycleBriefing>

Briefings produced at past cycle boundaries, in chronological order. Bounded growth: one entry per cycle, briefing capped at ~3,000 tokens.

last_api_input_tokens: Option<u32>

Provider-reported usage.input_tokens from the most recent API round (overwrite per round — not summed across tool-call rounds). Authoritative for “context size at last inference” per DeepSeek API docs.

temperature: Option<f32>

Per-session sampling overrides (optional). None → provider / model defaults.

top_p: Option<f32>

max_output_tokens: Option<u32>

Max output tokens for API requests; when unset, model-specific default applies.

Implementations

impl Session

pub fn record_api_round_usage(&mut self, usage: &Usage)

Record per-round API usage. Turn totals still sum via Turn::add_usage.

impl Session

pub fn new( model: String, workspace: PathBuf, allow_shell: bool, trust_mode: bool, notes_path: PathBuf, mcp_config_path: PathBuf, ) -> Self

Create a new session

pub fn add_message(&mut self, message: Message)

Add a message to the conversation

pub fn rebuild_working_set(&mut self)

Rebuild the working set from current messages (best effort).

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.