react_loop/

react_loop.rs

use anyhow::Result;
use praxis_graph::{Graph, GraphConfig, GraphInput, LLMConfig, StreamEvent};
use praxis_llm::{Content, Message, OpenAIClient};
use praxis_mcp::{MCPClient, MCPToolExecutor};
use std::io::{self, Write};
use std::sync::Arc;
use tokio;

#[tokio::main]
async fn main() -> Result<()> {
    println!("╔════════════════════════════════════════════════════════════╗");
    println!("║         Praxis React Agent - Interactive Demo             ║");
    println!("╚════════════════════════════════════════════════════════════╝");
    println!();
    println!("This demo shows a React agent that can:");
    println!("  • Think through problems (reasoning)");
    println!("  • Use tools from MCP servers");
    println!("  • Respond to your questions");
    println!();
    println!("Prerequisites:");
    println!("  1. Set OPENAI_API_KEY: export OPENAI_API_KEY=your_key");
    println!("  2. Set MCP_SERVERS: export MCP_SERVERS=\"http://localhost:8000/mcp,http://localhost:8001/mcp\"");
    println!("  3. Start MCP servers: cd mcp_servers/weather && uv run python weather.py");
    println!();
    println!("Type 'exit' to quit");
    println!();

    // Get API key from environment
    let api_key = std::env::var("OPENAI_API_KEY").expect(
        "OPENAI_API_KEY must be set in environment. Run: export OPENAI_API_KEY=your_key_here"
    );

    // Parse MCP servers from environment
    let mcp_servers = std::env::var("MCP_SERVERS")
        .unwrap_or_else(|_| "http://localhost:8005/mcp".to_string());

    // Create MCP tool executor (aggregates multiple servers)
    let mcp_executor = Arc::new(MCPToolExecutor::new());

    // Connect to each MCP server
    println!("Connecting to MCP servers...");
    for url in mcp_servers.split(',') {
        let url = url.trim();
        if !url.is_empty() {
            print!("  Connecting to {}... ", url);
            io::stdout().flush()?;
            match MCPClient::new_http(
                &format!("mcp-{}", uuid::Uuid::new_v4()),
                url
            ).await {
                Ok(client) => {
                    mcp_executor.add_server(client).await?;
                    println!("✓");
                }
                Err(e) => {
                    println!("✗ Failed: {}", e);
                    println!("Make sure the MCP server is running at {}", url);
                    return Err(e);
                }
            }
        }
    }
    println!();

    // Create LLM client
    let llm_client = Arc::new(OpenAIClient::new(api_key)?);

    // Create graph config
    let config = GraphConfig::default();

    // Create graph
    let graph = Graph::new(llm_client, mcp_executor, config);

    // Conversation loop
    let conversation_id = uuid::Uuid::new_v4().to_string();
    let mut conversation_history: Vec<Message> = Vec::new();
    
    loop {
        // Get user input
        print!("\n\x1b[1;36m You: \x1b[0m");
        io::stdout().flush()?;

        let mut input = String::new();
        io::stdin().read_line(&mut input)?;
        let input = input.trim();

        if input.is_empty() {
            continue;
        }

        if input.eq_ignore_ascii_case("exit") {
            println!("\nGoodbye!");
            break;
        }

        // Create user message
        let user_message = Message::Human {
            content: Content::text(input),
            name: None,
        };
        
        // Add to conversation history
        conversation_history.push(user_message);

        // Create graph input with full conversation history
        let llm_config = LLMConfig::new("gpt-4")
            .with_temperature(0.7)
            .with_max_tokens(4096);

        let graph_input = GraphInput::new(
            conversation_id.clone(),
            conversation_history.clone(),
            llm_config
        );

        // Spawn execution (no persistence for this example)
        let mut event_rx = graph.spawn_run(graph_input, None);

        // Print assistant label
        print!("\n\x1b[1;32mAssistant:\x1b[0m ");
        io::stdout().flush()?;

        let mut in_reasoning = false;
        let mut in_message = false;
        let mut assistant_response = String::new();

        // Process events
        while let Some(event) = event_rx.recv().await {
            match event {
                StreamEvent::InitStream { .. } => {
                    // Silent - just track
                }

                StreamEvent::Reasoning { content } => {
                    if !in_reasoning {
                        print!("\n\x1b[2;3mReasoning: ");
                        in_reasoning = true;
                        in_message = false;
                    }
                    print!("{}", content);
                    io::stdout().flush()?;
                }

                StreamEvent::Message { content } => {
                    if !in_message {
                        if in_reasoning {
                            print!("\x1b[0m\n\n");
                        }
                        print!("\x1b[0m");
                        in_message = true;
                        in_reasoning = false;
                    }
                    print!("{}", content);
                    assistant_response.push_str(&content);
                    io::stdout().flush()?;
                }

                StreamEvent::ToolCall {
                    index: _,
                    id: _,
                    name,
                    arguments,
                } => {
                    if in_reasoning {
                        print!("\x1b[0m\n");
                    }
                    if let Some(name) = name {
                        if let Some(args) = arguments {
                            print!("\n\x1b[1;33mCalling tool: {} ({})\x1b[0m", name, args);
                        } else {
                            print!("\n\x1b[1;33mCalling tool: {}\x1b[0m", name);
                        }
                        io::stdout().flush()?;
                    }
                    in_reasoning = false;
                    in_message = false;
                }

                StreamEvent::ToolResult {
                    tool_call_id: _,
                    result,
                    is_error,
                    duration_ms,
                } => {
                    if is_error {
                        print!(
                            "\n\x1b[1;31mTool error ({}ms): {}\x1b[0m",
                            duration_ms, result
                        );
                    } else {
                        // Truncate long results
                        let display_result = if result.len() > 100 {
                            format!("{}...", &result[..100])
                        } else {
                            result
                        };
                        print!(
                            "\n\x1b[1;32mTool result ({}ms): {}\x1b[0m",
                            duration_ms, display_result
                        );
                    }
                    io::stdout().flush()?;
                    in_reasoning = false;
                    in_message = false;
                }

                StreamEvent::Done { finish_reason: _ } => {
                    // LLM stream done, continue to next node
                }

                StreamEvent::Error { message, .. } => {
                    print!("\n\n\x1b[1;31mError: {}\x1b[0m", message);
                    io::stdout().flush()?;
                    break;
                }

                StreamEvent::EndStream {
                    status: _,
                    total_duration_ms,
                } => {
                    print!("\n\n\x1b[2m[Completed in {}ms]\x1b[0m", total_duration_ms);
                    io::stdout().flush()?;
                    break;
                }
            }
        }
        
        // Add assistant response to conversation history
        if !assistant_response.is_empty() {
            conversation_history.push(Message::AI {
                content: Some(Content::text(assistant_response)),
                tool_calls: None,
                name: None,
            });
        }

        println!(); // Final newline
    }

    Ok(())
}