AG-UI WASM Worker Test - CopilotKit's Agent User Interaction Protocol

AG-UI (Agent User Interaction Protocol) is an open, lightweight, event-based protocol created by CopilotKit that standardizes how AI agents communicate with user interfaces in real-time.

🔄 Real-time Streaming: AI agents send events as they work (like typing indicators and progressive responses)
📋 Standardized Events: Common event types like RUN_STARTED, TEXT_MESSAGE_CONTENT, etc.
🌐 Universal Protocol: Works across different AI providers and user interfaces
⚡ Live Updates: Users see AI thinking and responding in real-time, not just final results

99%

Rust Code

JavaScript

400+

Lines Rust

Lines JS

🔧 Complete Web Service in Rust: HTTP handling, HTML interface, and AG-UI protocol (by CopilotKit) - all in Rust via WASM
⚡ Real-time Streaming: Server-Sent Events with native Rust Web Streams API integration
🛡️ Type Safety: Full Rust type checking across the entire stack with zero runtime errors
🌐 Production Ready: Proper CORS, error handling, and async streams in serverless environment
📦 Self-Contained: This HTML page is embedded as a Rust string constant!

Click "🚀 Run Agent" to see exactly 5 AG-UI events stream in real-time. Here's what each one means:

RUN_STARTED: Workflow begins - Rust router processes your request and initializes the AG-UI stream
TEXT_MESSAGE_START: Assistant message begins - UUID generated in Rust for message tracking
TEXT_MESSAGE_CONTENT: Message content streams - Demonstrates real-time delta content delivery
TEXT_MESSAGE_END: Message complete - Same UUID links all message events together
RUN_FINISHED: Workflow complete - Stream closes and resources cleaned up automatically

💡 All events happen synchronously in this demo, but in production they could be spaced out as real AI processing occurs!

Architecture: Browser → Cloudflare Worker V8 Isolate → JavaScript shim (26 lines) → WASM module → Rust code (400+ lines)
WASM Compilation: Rust source compiled to WebAssembly binary via wasm-bindgen, running in V8's secure isolate sandbox
JavaScript Shim: Minimal 26-line loader that initializes WASM module and forwards requests to Rust handler
V8 Isolate: Each request runs in its own isolated V8 context with deterministic execution and memory limits
Stream Flow: Rust creates ReadableStream → SSEEncoder formats events → Server-Sent Events → Browser EventSource API
Type Safety: Every event uses strongly-typed Rust structs from ag-ui-wasm crate, compiled to WASM with zero runtime overhead
Protocol: Full AG-UI compliance with proper event lifecycle management (CopilotKit's protocol)
Performance: Zero-copy WASM integration, automatic memory management, and V8 JIT optimization

🤖 AG-UI WASM Worker Test (Pure Rust) - CopilotKit Protocol