Genkit MCP

# Realtime Tracing Demo This sample demonstrates Genkit's realtime tracing feature, which exports spans to the DevUI as they **start** (not just when they complete). This enables live visualization of in-progress operations. ## What is Realtime Tracing? Standard OpenTelemetry processors only export spans when they finish. This means long-running operations (like multi-turn LLM calls or complex workflows) don't appear in the DevUI until they're complete. With realtime tracing enabled: - Spans appear in the DevUI **immediately** when they start - You can see operations **in progress** (without endTime) - The span is exported again when it completes with full data ``` Standard Tracing: Realtime Tracing: Start ─────────────────► Start ────► [Span appears!] (nothing visible) │ ... │ (visible as "in progress") ... │ End ──────► [Span appears] End ──┴─► [Span updated] ``` ## How It Works The `RealtimeSpanProcessor` wraps a standard exporter and calls `export()` twice: 1. On `on_start()` - exports immediately (no endTime) 2. On `on_end()` - exports again with complete data ## Usage ### Enable via Environment Variable ```bash # Enable realtime telemetry export GENKIT_ENABLE_REALTIME_TELEMETRY=true # Run with genkit start genkit start -- python src/main.py ``` ### Enable Programmatically ```python from opentelemetry.sdk.trace import TracerProvider from genkit.core.trace import RealtimeSpanProcessor, TelemetryServerSpanExporter # Create exporter exporter = TelemetryServerSpanExporter( telemetry_server_url='http://localhost:4000' ) # Wrap with RealtimeSpanProcessor processor = RealtimeSpanProcessor(exporter) # Add to tracer provider provider = TracerProvider() provider.add_span_processor(processor) ``` ## Running the Demo 1. Run with realtime tracing enabled (with hot reload): ```bash ./run.sh ``` You'll be prompted for `GEMINI_API_KEY` if not set. 2. Open the DevUI at http://localhost:4000 3. Trigger flows and watch spans appear **immediately** as operations start! 4. Edit code and it will automatically reload. ## Key APIs Demonstrated | API | Description | |-----|-------------| | `RealtimeSpanProcessor` | SpanProcessor that exports on start AND end | | `is_realtime_telemetry_enabled()` | Check if realtime mode is enabled | | `create_span_processor(exporter)` | Auto-selects processor based on env | | `GENKIT_ENABLE_REALTIME_TELEMETRY` | Environment variable to enable | ## When to Use - **Development**: Great for debugging and understanding flow execution - **Long-running operations**: See progress of complex workflows - **DevUI demos**: Showcase live updates ## When NOT to Use - **Production**: Doubles network traffic (each span exported twice) - **High-throughput**: May impact performance - **Simple flows**: Standard tracing is sufficient ## Related Samples - `session-demo/` - Multi-turn conversations - `chat-demo/` - Chat application with streaming - `tool-interrupts/` - Human-in-the-loop workflows