Crate systemprompt_events 

Server-Sent Events (SSE) broadcasting infrastructure for systemprompt.io.

This crate hosts the in-process event bus that fans out A2A, AG-UI, analytics, and context events to per-user SSE connections. It is shared between the HTTP API entry crate and the runtime layer so that any component holding a UserId can publish typed events without knowing about the wire format.

Modules

• services — the GenericBroadcaster implementation, the per-event broadcaster type aliases, and the static EventRouter.
• sse — the ToSse trait and serde-driven implementations that convert systemprompt_models event types into axum SSE records.
• error — the public EventError / EventResult surface.

Feature flags

This crate has no Cargo features; everything compiles by default.

Example

use systemprompt_events::{A2A_BROADCASTER, Broadcaster};
use systemprompt_identifiers::UserId;
use systemprompt_models::A2AEvent;

let user_id = UserId::new("user_abc");
let delivered = A2A_BROADCASTER.broadcast(&user_id, event).await;
tracing::info!(delivered, "A2A event fanned out");

Re-exports

pub use error::EventError;

pub use error::EventResult;

pub use sse::ToSse;

pub use extension::EventsExtension;

pub use services::A2A_BROADCASTER;

pub use services::A2ABroadcaster;

pub use services::AGUI_BROADCASTER;

pub use services::ANALYTICS_BROADCASTER;

pub use services::AgUiBroadcaster;

pub use services::AnalyticsBroadcaster;

pub use services::CONTEXT_BROADCASTER;

pub use services::ConnectionGuard;

pub use services::ContextBroadcaster;

pub use services::EventRouter;

pub use services::GenericBroadcaster;

pub use services::HEARTBEAT_INTERVAL;

pub use services::HEARTBEAT_JSON;

pub use services::OUTBOX_CHANNEL;

pub use services::OutboxChannel;

pub use services::PostgresEventBridge;

pub use services::standard_keep_alive;

Modules

error

Error types raised by the event-broadcasting infrastructure.

extension

Extension-framework registration for the events crate.

services

Broadcaster implementations, the static fan-out EventRouter, and the cross-replica PostgresEventBridge.

sse

Conversion from typed event payloads into axum Server-Sent Event records.

Constants

SSE_BUFFER

Traits

Broadcaster

Type Aliases

EventSender