phoenix-observability

# Phoenix - AI Observability Platform Open-source AI observability and evaluation platform for LLM applications with tracing, evaluation, datasets, experiments, and real-time monitoring. ## When to use Phoenix **Use Phoenix when:** - Debugging LLM application issues with detailed traces - Running systematic evaluations on datasets - Monitoring production LLM systems in real-time - Building experiment pipelines for prompt/model comparison - Self-hosted observability without vendor lock-in **Key features:** - **Tracing**: OpenTelemetry-based trace collection for any LLM framework - **Evaluation**: LLM-as-judge evaluators for quality assessment - **Datasets**: Versioned test sets for regression testing - **Experiments**: Compare prompts, models, and configurations - **Playground**: Interactive prompt testing with multiple models - **Open-source**: Self-hosted with PostgreSQL or SQLite **Use alternatives instead:** - **LangSmith**: Managed platform with LangChain-first integration - **Weights & Biases**: Deep learning experiment tracking focus - **Arize Cloud**: Managed Phoenix with enterprise features - **MLflow**: General ML lifecycle, model registry focus ## Quick start ### Installation ```bash pip install arize-phoenix # With specific backends pip install arize-phoenix[embeddings] # Embedding analysis pip install arize-phoenix-otel # OpenTelemetry config pip install arize-phoenix-evals # Evaluation framework pip install arize-phoenix-client # Lightweight REST client ``` ### Launch Phoenix server ```python import phoenix as px # Launch in notebook (ThreadServer mode) session = px.launch_app() # View UI session.view() # Embedded iframe print(session.url) # http://localhost:6006 ``` ### Command-line server (production) ```bash # Start Phoenix server phoenix serve # With PostgreSQL export PHOENIX_SQL_DATABASE_URL="postgresql://user:pass@host/db" phoenix serve --port 6006 ``` ### Basic tracing ```python from phoenix.otel import register from openinference.instrumentation.openai import OpenAIInstrumentor # Configure OpenTelemetry with Phoenix tracer_provider = register( project_name="my-llm-app", endpoint="http://localhost:6006/v1/traces" ) # Instrument OpenAI SDK OpenAIInstrumentor().instrument(tracer_provider=tracer_provider) # All OpenAI calls are now traced from openai import OpenAI client = OpenAI() response = client.chat.completions.create( model="gpt-4o", messages=[{"role": "user", "content": "Hello!"}] ) ``` ## Core concepts ### Traces and spans A **trace** represents a complete execution flow, while **spans** are individual operations within that trace. ```python from phoenix.otel import register from opentelemetry import trace # Setup tracing tracer_provider = register(project_name="my-app") tracer = trace.get_tracer(__name__) # Create custom spans with tracer.start_as_current_span("process_query") as span: span.set_attribute("input.value", query) # Child spans are automatically nested with tracer.start_as_current_span("retrieve_context"): context = retriever.search(query) with tracer.start_as_current_span("generate_response"): response = llm.generate(query, context) span.set_attribute("output.value", response) ``` ### Projects Projects organize related traces: ```python import os os.environ["PHOENIX_PROJECT_NAME"] = "production-chatbot" # Or per-trace from phoenix.otel import register tracer_provider = register(project_name="experiment-v2") ``` ## Framework instrumentation ### OpenAI ```python from phoenix.otel import register from openinference.instrumentation.openai import OpenAIInstrumentor tracer_provider = register() OpenAIInstrumentor().instrument(tracer_provider=tracer_provider) ``` ### LangChain ```python from phoenix.otel import register from openinference.instrumentation.langchain import LangChainInstrumentor tracer_provider = register() LangChainInstrumentor().instrument(tracer_provider=tracer_provider) # All LangChain operations traced from langchain_openai import ChatOpenAI llm = ChatOpenAI(model="gpt-4o") response = llm.invoke("Hello!") ``` ### LlamaIndex ```python from phoenix.otel import register from openinference.instrumentation.llama_index import LlamaIndexInstrumentor tracer_provider = register() LlamaIndexInstrumentor().instrument(tracer_provider=tracer_provider) ``` ### Anthropic ```python from phoenix.otel import register from openinference.instrumentation.anthropic import AnthropicInstrumentor tracer_provider = register() AnthropicInstrumentor().instrument(tracer_provider=tracer_provider) ``` ## Evaluation framework ### Built-in evaluators ```python from phoenix.evals import ( OpenAIModel, HallucinationEvaluator, RelevanceEvaluator, ToxicityEvaluator, llm_classify ) # Setup model for evaluation eval_model = OpenAIModel(model="gpt-4o") # Evaluate hallucination hallucination_eval = HallucinationEvaluator(eval_model) results = hallucination_eval.evaluate( input="What is the capital of France?", output="The capital of France is Paris.", reference="Paris is the capital of France." ) ``` ### Custom evaluators ```python from phoenix.evals import llm_classify # Define custom evaluation def evaluate_helpfulness(input_text, output_text): template = """ Evaluate if the response is helpful for the given question. Question: {input} Response: {output} Is this response helpful? Answer 'helpful' or 'not_helpful'. """ result = llm_classify( model=eval_model, template=template, input=input_text, output=output_text, rails=["helpful", "not_helpful"] ) return result ``` ### Run evaluations on dataset ```python from phoenix import Client from phoenix.evals import run_evals client = Client() # Get spans to evaluate spans_df = client.get_spans_dataframe( project_name="my-app", filter_condition="span_kind == 'LLM'" ) # Run evaluations eval_results = run_evals( dataframe=spans_df, evaluators=[ HallucinationEvaluator(eval_model), RelevanceEvaluator(eval_model) ], provide_explanation=True ) # Log results back to Phoenix client.log_evaluations(eval_results) ``` ## Datasets and experiments ### Create dataset ```python from phoenix import Client client = Client() # Create dataset dataset = client.create_dataset( name="qa-test-set", description="QA evaluation dataset" ) # Add examples client.add_examples_to_dataset( dataset_name="qa-test-set", examples=[ { "input": {"question": "What is Python?"}, "output": {"answer": "A programming language"} }, { "input": {"question": "What is ML?"}, "output": {"answer": "Machine learning"} } ] ) ``` ### Run experiment ```python from phoenix import Client from phoenix.experiments import run_experiment client = Client() def my_model(input_data): """Your model function.""" question = input_data["question"] return {"answer": generate_answer(question)} def accuracy_evaluator(input_data, output, expected): """Custom evaluator.""" return { "score": 1.0 if expected["answer"].lower() in output["answer"].lower() else 0.0, "label": "correct" if expected["answer"].lower() in output["answer"].lower() else "incorrect" } # Run experiment results = run_experiment( dataset_name="qa-test-set", task=my_model, evaluators=[accuracy_evaluator], experiment_name="baseline-v1" ) print(f"Average accuracy: {results.aggregate_metrics['accuracy']}") ``` ## Client API ### Query traces and spans ```python from phoenix import Client client = Client(endpoint="http://localhost:6006") # Get spans as DataFrame spans_df = client.get_spans_dataframe( project_name="my-app", filter_condition="span_kind == 'LLM'", limit=1000 ) # Get specific span span = client.get_span(span_id="abc123") # Get trace trace = client.get_trace(trace_id="xyz789") ``` ### Log feedback ```python from phoenix import Client client = Client() # Log user feedback client.log_annotation( span_id="abc123", name="user_rating", annotator_kind="HUMAN", score=0.8, label="helpful", metadata={"comment": "Good response"} ) ``` ### Export data ```python # Export to pandas df = client.get_spans_dataframe(project_name="my-app") # Export traces traces = client.list_traces(project_name="my-app") ``` ## Production deployment ### Docker ```bash docker run -p 6006:6006 arizephoenix/phoenix:latest ``` ### With PostgreSQL ```bash # Set database URL export PHOENIX_SQL_DATABASE_URL="postgresql://user:pass@host:5432/phoenix" # Start server phoenix serve --host 0.0.0.0 --port 6006 ``` ### Environment variables | Variable | Description | Default | |----------|-------------|---------| | `PHOENIX_PORT` | HTTP server port | `6006` | | `PHOENIX_HOST` | Server bind address | `127.0.0.1` | | `PHOENIX_GRPC_PORT` | gRPC/OTLP port | `4317` | | `PHOENIX_SQL_DATABASE_URL` | Database connection | SQLite temp | | `PHOENIX_WORKING_DIR` | Data storage directory | OS temp | | `PHOENIX_ENABLE_AUTH` | Enable authentication | `false` | | `PHOENIX_SECRET` | JWT signing secret | Required if auth enabled | ### With authentication ```bash export PHOENIX_ENABLE_AUTH=true export PHOENIX_SECRET="your-secret-key-min-32-chars" export PHOENIX_ADMIN_SECRET="admin-bootstrap-token" phoenix serve ``` ## Best practices 1. **Use projects**: Separate traces by environment (dev/staging/prod) 2. **Add metadata**: Include user IDs, session IDs for debugging 3. **Evaluate regularly**: Run automated evaluations in CI/CD 4. **Version datasets**: Track test set changes over time 5. **Monitor costs**: Track token usage via Phoenix dashboards 6. **Self-host**: Use PostgreSQL for production deployments ## Common issues **Traces not appearing:** ```python from phoenix.otel import register # Verify endpoint tracer_provider = register( project_name="my-app", endpoint="http://localhost:6006/v1/traces" # Correct endpoint ) # Force flush from opentelemetry import trace trace.get_tracer_provider().force_flush() ``` **High memory in notebook:** ```python # Close session when done session = px.launch_app() # ... do work ... session.close() px.close_app() ``` **Database connection issues:** ```bash # Verify PostgreSQL connection psql $PHOENIX_SQL_DATABASE_URL -c "SELECT 1" # Check Phoenix logs phoenix serve --log-level debug ``` ## References - **[Advanced Usage](references/advanced-usage.md)** - Custom evaluators, experiments, production setup - **[Troubleshooting](references/troubleshooting.md)** - Common issues, debugging, performance ## Resources - **Documentation**: https://docs.arize.com/phoenix - **Repository**: https://github.com/Arize-ai/phoenix - **Docker Hub**: https://hub.docker.com/r/arizephoenix/phoenix - **Version**: 12.0.0+ - **License**: Apache 2.0 --- > Converted and distributed by [TomeVault](https://tomevault.io) | [Claim this content](https://tomevault.io/claim/davila7/claude-code-templates) <!-- tomevault:2.0:skill_md:2026-04-05 -->