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systemprompt.io • GitHub • Documentation

systemprompt-events

Events module for systemprompt.io - event broadcasting and routing.

Overview

Part of the Infra layer in the systemprompt.io architecture.

This crate provides a type-safe, generic event broadcasting system for real-time communication with connected clients via SSE (Server-Sent Events). It manages connection lifecycles, routes events to appropriate channels, and handles automatic cleanup of disconnected clients.

File Structure

crates/infra/events/
├── Cargo.toml
├── README.md
├── status.md
└── src/
    ├── lib.rs                      # 27 lines  - Trait definitions, type aliases, re-exports
    └── services/
        ├── mod.rs                  # 10 lines  - Module re-exports
        ├── broadcaster.rs          # 191 lines - GenericBroadcaster implementation
        └── routing.rs              # 51 lines  - EventRouter, global singletons

Modules

lib.rs

Entry point defining core abstractions:

• Broadcaster trait - Type-safe async broadcasting with connection management
• EventSender type alias - Channel sender for SSE events (UnboundedSender<Result<Event, Infallible>>)

services/broadcaster.rs

Generic broadcaster implementation:

• GenericBroadcaster<E> - Thread-safe broadcaster using Arc<RwLock<HashMap<UserId, HashMap<ConnId, Sender>>>>
• ConnectionGuard<E> - RAII guard for automatic connection cleanup on drop
• Type aliases: AgUiBroadcaster, A2ABroadcaster, ContextBroadcaster, AnalyticsBroadcaster
• Keep-alive utilities: standard_keep_alive(), HEARTBEAT_INTERVAL, HEARTBEAT_JSON

services/routing.rs

Event routing and global state:

• EventRouter - Routes events to appropriate broadcaster(s)
• Global singletons: AGUI_BROADCASTER, A2A_BROADCASTER, CONTEXT_BROADCASTER, ANALYTICS_BROADCASTER

Public API

Traits

Types

Constants

Global Singletons

Event Flow

                    ┌─────────────────┐
                    │   EventRouter   │
                    └────────┬────────┘
                             │
        ┌────────────────────┼────────────────────┐
        │                    │                    │
        ▼                    ▼                    ▼
┌───────────────┐    ┌───────────────┐    ┌───────────────┐
│AGUI_BROADCASTER│    │A2A_BROADCASTER│    │CONTEXT_BROADCASTER│
└───────┬───────┘    └───────┬───────┘    └───────┬───────┘
        │                    │                    │
        ▼                    ▼                    ▼
   SSE Clients          SSE Clients          SSE Clients

AgUI and A2A events are routed to both their primary broadcaster AND the context broadcaster for aggregation.

Dependencies

Installation

Add to your Cargo.toml:

[dependencies]
systemprompt-events = "0.0.1"

Tests

Tests are located in crates/tests/unit/infra/events/ following the project convention of separating tests from source files.

License

FSL-1.1-ALv2 - See LICENSE for details.