Enum EventTag 

#[repr(u32)]
pub enum EventTag {
    ProjectTrust = 0,
    ResourcesDiscover = 1,
    SessionStart = 2,
    SessionInfoChanged = 3,
    SessionBeforeSwitch = 4,
    SessionBeforeFork = 5,
    SessionBeforeCompact = 6,
    SessionCompact = 7,
    SessionShutdown = 8,
    SessionBeforeTree = 9,
    SessionTree = 10,
    Context = 11,
    BeforeProviderRequest = 12,
    BeforeProviderHeaders = 13,
    AfterProviderResponse = 14,
    BeforeAgentStart = 15,
    AgentStart = 16,
    AgentEnd = 17,
    AgentSettled = 18,
    TurnStart = 19,
    TurnEnd = 20,
    MessageStart = 21,
    MessageUpdate = 22,
    MessageEnd = 23,
    ToolExecutionStart = 24,
    ToolExecutionUpdate = 25,
    ToolExecutionEnd = 26,
    ModelSelect = 27,
    ThinkingLevelSelect = 28,
    ToolCall = 29,
    ToolResult = 30,
    UserBash = 31,
    Input = 32,
    BeforeTuiStart = 33,
    UiPromptStart = 34,
    UiPromptEnd = 35,
}

Discriminant for StablePluginEvent, one variant per pi on() category (33 total) plus one rpi-specific category (34 total). #[repr(u32)] pins the discriminant width.

The 33 Pi categories (verified against extensions/types.ts:1203-1244): project_trust, resources_discover, session_start, session_info_changed, session_before_switch, session_before_fork, session_before_compact, session_compact, session_shutdown, session_before_tree, session_tree, context, before_provider_request, before_provider_headers, after_provider_response, before_agent_start, agent_start, agent_end, agent_settled, turn_start, turn_end, message_start, message_update, message_end, tool_execution_start, tool_execution_update, tool_execution_end, model_select, thinking_level_select, tool_call, tool_result, user_bash, input.

BeforeTuiStart is rpi-specific (not a Pi category): dispatched once before the interactive TUI is initialized, so extensions can prepare (connect a server, load a resource) before the UI starts. Appended last so existing discriminants keep their values (ABI-safe for already-compiled plugins).

Variants

ProjectTrust = 0

ResourcesDiscover = 1

SessionStart = 2

SessionInfoChanged = 3

SessionBeforeSwitch = 4

SessionBeforeFork = 5

SessionBeforeCompact = 6

SessionCompact = 7

SessionShutdown = 8

SessionBeforeTree = 9

SessionTree = 10

Context = 11

BeforeProviderRequest = 12

BeforeProviderHeaders = 13

AfterProviderResponse = 14

BeforeAgentStart = 15

AgentStart = 16

AgentEnd = 17

AgentSettled = 18

TurnStart = 19

TurnEnd = 20

MessageStart = 21

MessageUpdate = 22

MessageEnd = 23

ToolExecutionStart = 24

ToolExecutionUpdate = 25

ToolExecutionEnd = 26

ModelSelect = 27

ThinkingLevelSelect = 28

ToolCall = 29

ToolResult = 30

UserBash = 31

Input = 32

BeforeTuiStart = 33

rpi-specific: dispatched before the interactive TUI initializes (not a Pi on() category). Appended last so existing discriminants are stable.

UiPromptStart = 34

Pi on() category: dispatched when the TUI shows an interactive prompt (selector, dialog, etc.) that blocks agent work.

UiPromptEnd = 35

Pi on() category: dispatched when the TUI prompt is dismissed.

Trait Implementations

impl Clone for EventTag

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for EventTag

impl Debug for EventTag

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

Formats the value using the given formatter.

impl Eq for EventTag

impl PartialEq for EventTag

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for EventTag