Show HN: Radkit, A2A focused rust agents SDK

1 month ago 2

Radkit is an agent framework for building AI agents in Rust. It aims to provide comprehensive support for the A2A (Agent-to-Agent) Protocol.

Radkit offers:

🚀 A2A-Native Design: Unlike other agent frameworks (Autogen, CrewAI, Langchain, ADK) where a2a is a secondary layer, Radkit is built from the ground up to support the protocol natively.
🤖 Multi-Provider LLM Support: Anthropic Claude, Google Gemini, OpenAI and more coming soon
🔧 Advanced Tool System: Function calling with built-in task management tools, MCP Tools

[dependencies] radkit = "0.0.2" futures = "0.3.31" tokio = "1.47.1" uuid = "1.18.0" dotenvy = "0.15.7"

Create a .env file with your Anthropic API key:

ANTHROPIC_API_KEY="YOUR_API_KEY"

Then, create an agent and send a message:

use futures::StreamExt; use radkit::a2a::{ Message, MessageRole, MessageSendParams, Part, SendStreamingMessageResult, TaskState, }; use radkit::agents::{Agent, AgentConfig}; use radkit::models::AnthropicLlm; use radkit::sessions::InMemorySessionService; #[tokio::main] async fn main() -> Result<(), Box<dyn std::error::Error>> { // Load environment variables from .env file. dotenvy::dotenv()?; // Create an LLM provider (supports Anthropic, Gemini, and Mock providers) let llm = AnthropicLlm::new( "claude-3-5-sonnet-20241022".to_string(), std::env::var("ANTHROPIC_API_KEY")?, ); // Create an agent using the builder pattern with built-in task management tools let agent = Agent::builder( "You are a helpful research assistant. When working on tasks, \ always use update_status to indicate your progress (e.g., 'working' \ when processing, 'completed' when done). When you produce any \ results or findings, save them using save_artifact so they can be \ retrieved later.", llm, ) .with_card(|c| { c.with_name("research_assistant") .with_description("Research Assistant") }) .with_config(AgentConfig::default().with_max_iterations(10)) .with_session_service(InMemorySessionService::new()) .with_builtin_task_tools() // Enables update_status and save_artifact tools .build(); // User simply asks for research - no mention of tools let message = Message { kind: "message".to_string(), message_id: uuid::Uuid::new_v4().to_string(), role: MessageRole::User, parts: vec![Part::Text { text: "Can you research the Fibonacci sequence and create a \ summary of its properties and applications?" .to_string(), metadata: None, }], context_id: None, // New session will be created task_id: None, // New task will be created reference_task_ids: Vec::new(), extensions: Vec::new(), metadata: None, }; // Stream the execution to capture real-time A2A protocol events let mut execution = agent .send_streaming_message( "my_app".to_string(), "user123".to_string(), MessageSendParams { message, configuration: None, metadata: None, }, ) .await?; let mut status_events = 0; let mut artifact_events = 0; let mut final_task = None; // Process streaming results and capture A2A protocol events while let Some(event) = execution.a2a_stream.next().await { match event { SendStreamingMessageResult::TaskStatusUpdate(status_event) => { status_events += 1; println!("📊 Status Update: {:?}", status_event.status.state); if status_event.status.message.is_some() { println!( " Message: {:?}", status_event.status.message.as_ref().unwrap() ); } } SendStreamingMessageResult::TaskArtifactUpdate(artifact_event) => { artifact_events += 1; println!("💾 Artifact Saved: {:?}", artifact_event.artifact.name); } SendStreamingMessageResult::Task(task) => { println!("✅ Task Completed: {}", task.id); final_task = Some(task); break; } _ => {} // Handle other events as needed } } // Examine the final task state if let Some(task) = final_task { println!("\n📈 Final Results:"); println!(" Task State: {:?}", task.status.state); println!(" Messages: {}", task.history.len()); println!(" Artifacts: {}", task.artifacts.len()); // Check the saved artifact content if let Some(artifact) = task.artifacts.first() { if let Some(Part::Text { text, .. }) = artifact.parts.first() { println!( " Artifact Content Preview: {}", &text[..text.len().min(200)] ); } } } Ok(()) }

Protocol Methods: Implements message/send, message/stream, tasks/get
Event Streaming: Tools can generate compliant TaskStatusUpdate and TaskArtifactUpdate events

Comprehensive Task System

Follows Task Lifecycle: Submitted → Working → [InputRequired/AuthRequired] → Completed/Failed
Atomic Operations: Thread-safe message, artifact, and status updates
A2A Events: Automatic generation of protocol-compliant events
Built-in Tools: update_status and save_artifact with event emission

Current Version: 0.0.1 (Work in Progress - Major Architecture Complete)

✅ Completed Features: