Enum AppEvent 

pub enum AppEvent {
    Terminal(Event),
    Key(KeyEvent),
    Resize(u16, u16),
    ScrollUp,
    ScrollDown,
    MouseDown {
        col: u16,
        row: u16,
    },
    MouseDrag {
        col: u16,
        row: u16,
    },
    MouseUp {
        col: u16,
        row: u16,
    },
    FocusGained,
    Tick,
    AgentStarted,
    AgentChunk(String),
    AgentMessage(ChatMessage),
    AgentFinished,
    AgentError(String),
    ToolStarted {
        tool_id: String,
        tool_name: String,
        args: HashMap<String, Value>,
    },
    ToolOutput {
        tool_id: String,
        output: String,
    },
    ToolResult {
        tool_id: String,
        tool_name: String,
        output: String,
        success: bool,
        args: HashMap<String, Value>,
    },
    ToolFinished {
        tool_id: String,
        success: bool,
    },
    ToolApprovalRequired {
        tool_id: String,
        tool_name: String,
        description: String,
    },
    ToolApprovalRequested {
        command: String,
        working_dir: String,
        response_tx: Sender<ToolApprovalDecision>,
    },
    AskUserRequested {
        question: String,
        options: Vec<String>,
        default: Option<String>,
        response_tx: Sender<String>,
    },
    SubagentStarted {
        subagent_id: String,
        subagent_name: String,
        task: String,
        cancel_token: Option<CancellationToken>,
    },
    SubagentToolCall {
        subagent_id: String,
        subagent_name: String,
        tool_name: String,
        tool_id: String,
        args: HashMap<String, Value>,
    },
    SubagentToolComplete {
        subagent_id: String,
        subagent_name: String,
        tool_name: String,
        tool_id: String,
        success: bool,
    },
    SubagentFinished {
        subagent_id: String,
        subagent_name: String,
        success: bool,
        result_summary: String,
        tool_call_count: usize,
        shallow_warning: Option<String>,
    },
    SubagentTokenUpdate {
        subagent_id: String,
        subagent_name: String,
        input_tokens: u64,
        output_tokens: u64,
    },
    ReasoningContent(String),
    ReasoningBlockStart,
    TaskProgressStarted {
        description: String,
    },
    TaskProgressFinished,
    BudgetExhausted {
        cost_usd: f64,
        budget_usd: f64,
    },
    FileChangeSummary {
        files: usize,
        additions: u64,
        deletions: u64,
    },
    ContextUsage(f64),
    CompactionStarted,
    CompactionFinished {
        success: bool,
        message: String,
    },
    PlanApprovalRequested {
        plan_content: String,
        response_tx: Sender<PlanDecision>,
    },
    UserSubmit(String),
    Interrupt,
    SetInterruptToken(InterruptToken),
    AgentInterrupted,
    ModeChanged(String),
    KillTask(String),
    AgentBackgrounded {
        task_id: String,
        query_summary: String,
    },
    BackgroundAgentCompleted {
        task_id: String,
        success: bool,
        result_summary: String,
        full_result: String,
        cost_usd: f64,
        tool_call_count: usize,
    },
    BackgroundAgentProgress {
        task_id: String,
        tool_name: String,
        tool_count: usize,
    },
    BackgroundAgentKilled {
        task_id: String,
    },
    BackgroundNudge {
        content: String,
    },
    BackgroundAgentActivity {
        task_id: String,
        line: String,
    },
    SetBackgroundAgentToken {
        task_id: String,
        query: String,
        session_id: String,
        interrupt_token: InterruptToken,
    },
    SnapshotTaken {
        hash: String,
    },
    UndoResult {
        success: bool,
        message: String,
    },
    RedoResult {
        success: bool,
        message: String,
    },
    ShareResult {
        path: String,
    },
    FileChanged {
        paths: Vec<String>,
    },
    SessionTitleUpdated(String),
    Quit,
}

Application-level events consumed by the main event loop.

Variants

Terminal(Event)

Raw terminal event from crossterm.

Key(KeyEvent)

Key press (extracted from terminal event for convenience).

Resize(u16, u16)

Terminal resize.

ScrollUp

Mouse-wheel scroll up.

ScrollDown

Mouse-wheel scroll down.

MouseDown

Mouse button pressed at (col, row).

Fields

col: u16

row: u16

MouseDrag

Mouse dragged to (col, row) while button held.

Fields

col: u16

row: u16

MouseUp

Mouse button released at (col, row).

Fields

col: u16

row: u16

FocusGained

Terminal regained focus (user switched back to this tab/window).

Tick

Tick for periodic UI updates (spinner animation, etc.).

AgentStarted

Assistant started generating a response.

AgentChunk(String)

Streaming text chunk from the assistant.

AgentMessage(ChatMessage)

Complete assistant message received.

AgentFinished

Agent finished the current turn.

AgentError(String)

Agent encountered an error.

ToolStarted

A tool execution started.

Fields

tool_id: String

tool_name: String

args: HashMap<String, Value>

ToolOutput

A tool produced output.

Fields

tool_id: String

output: String

ToolResult

A tool produced its final result.

Fields

tool_id: String

tool_name: String

output: String

success: bool

args: HashMap<String, Value>

ToolFinished

A tool execution completed.

Fields

tool_id: String

success: bool

ToolApprovalRequired

Tool requires user approval (legacy, no channel — kept for recording compatibility).

Fields

tool_id: String

tool_name: String

description: String

ToolApprovalRequested

Tool approval request with bidirectional channel.

Fields

command: String

working_dir: String

response_tx: Sender<ToolApprovalDecision>

AskUserRequested

Ask-user request with bidirectional channel.

Fields

question: String

options: Vec<String>

default: Option<String>

response_tx: Sender<String>

SubagentStarted

A subagent started executing.

Fields

subagent_id: String

subagent_name: String

task: String

cancel_token: Option<CancellationToken>

SubagentToolCall

A subagent made a tool call (for nested display).

Fields

subagent_id: String

subagent_name: String

tool_name: String

tool_id: String

args: HashMap<String, Value>

SubagentToolComplete

A subagent tool call completed.

Fields

subagent_id: String

subagent_name: String

tool_name: String

tool_id: String

success: bool

SubagentFinished

A subagent finished its task.

Fields

subagent_id: String

subagent_name: String

success: bool

result_summary: String

tool_call_count: usize

shallow_warning: Option<String>

SubagentTokenUpdate

Token usage update from a subagent’s LLM call.

Fields

subagent_id: String

subagent_name: String

input_tokens: u64

output_tokens: u64

ReasoningContent(String)

Native reasoning content from LLM response (inline thinking).

ReasoningBlockStart

A new reasoning/thinking block started (separator between interleaved blocks).

TaskProgressStarted

Agent started working on a task (shows progress bar).

Fields

description: String

TaskProgressFinished

Agent finished the current task (hides progress bar).

BudgetExhausted

Session cost budget has been exhausted. The agent loop should pause.

Fields

cost_usd: f64

budget_usd: f64

FileChangeSummary

File change summary after a query completes.

Fields

files: usize

additions: u64

deletions: u64

ContextUsage(f64)

Context window usage percentage updated (0.0–100.0).

CompactionStarted

Manual compaction started (shows compaction spinner).

CompactionFinished

Manual compaction finished (hides compaction spinner, shows result).

Fields

success: bool

message: String

PlanApprovalRequested

Plan approval request arrived from the PresentPlanTool. Contains the plan content to display and the oneshot sender for the decision.

Fields

plan_content: String

response_tx: Sender<PlanDecision>

UserSubmit(String)

User submitted a message.

Interrupt

User requested interrupt (Escape).

SetInterruptToken(InterruptToken)

Set the interrupt token for the current query (sent by agent backend).

AgentInterrupted

Agent run was interrupted (sent by agent backend after cancellation).

ModeChanged(String)

Mode changed (normal/plan).

KillTask(String)

Kill a background task by ID.

AgentBackgrounded

An agent was moved to the background via Ctrl+B.

Fields

task_id: String

query_summary: String

BackgroundAgentCompleted

A background agent completed its work.

Fields

task_id: String

success: bool

result_summary: String

full_result: String

cost_usd: f64

tool_call_count: usize

BackgroundAgentProgress

Progress update from a background agent.

Fields

task_id: String

tool_name: String

tool_count: usize

BackgroundAgentKilled

A background agent was killed.

Fields

task_id: String

BackgroundNudge

LLM-generated nudge message after backgrounding agents.

Fields

content: String

BackgroundAgentActivity

Activity line from a background agent (tool call, reasoning, etc.).

Fields

task_id: String

line: String

SetBackgroundAgentToken

Register a background agent task with its interrupt token (sent from tui_runner).

Fields

task_id: String

query: String

session_id: String

interrupt_token: InterruptToken

SnapshotTaken

Snapshot was taken (stores tree hash for undo stack).

Fields

hash: String

UndoResult

Undo result from the runtime.

Fields

success: bool

message: String

RedoResult

Redo result from the runtime.

Fields

success: bool

message: String

ShareResult

Share result from the runtime.

Fields

path: String

FileChanged

File watcher detected changes.

Fields

paths: Vec<String>

SessionTitleUpdated(String)

Session title was auto-detected by the topic detector.

Quit

Quit the application.

Trait Implementations

impl Debug for AppEvent

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

Formats the value using the given formatter.