OpenInference PydanticAI

Python auto-instrumentation library for PydanticAI. These traces are fully OpenTelemetry compatible and can be sent to an OpenTelemetry collector for viewing, such as Arize Phoenix or Arize AX.

Installation

pip install openinference-instrumentation-pydantic-ai

Requires Pydantic AI 2.24.0 or newer.

Quickstart

This quickstart shows you how to instrument your PydanticAI agents.

Install required packages.

pip install "pydantic-ai>=2.24.0" arize-phoenix opentelemetry-sdk opentelemetry-exporter-otlp

Start Phoenix in the background as a collector. By default, it listens on http://localhost:6006. You can visit the app via a browser at the same address. (Phoenix does not send data over the internet. It only operates locally on your machine.)

phoenix serve

Here's a simple example that demonstrates how to use PydanticAI with OpenInference instrumentation:

import os
from pydantic import BaseModel
from pydantic_ai import Agent
from pydantic_ai.models.instrumented import InstrumentationSettings
from pydantic_ai.models.openai import OpenAIModel
from pydantic_ai.providers.openai import OpenAIProvider
from opentelemetry import trace
from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
from opentelemetry.sdk.trace import TracerProvider
from openinference.instrumentation.pydantic_ai import OpenInferenceSpanProcessor
from opentelemetry.sdk.trace.export import SimpleSpanProcessor

# Set your OpenAI API key
os.environ["OPENAI_API_KEY"] = "YOUR_OPENAI_API_KEY"

# Set up the tracer provider
tracer_provider = TracerProvider()
trace.set_tracer_provider(tracer_provider)

# Add the OpenInference span processor
endpoint = "http://127.0.0.1:6006/v1/traces"
exporter = OTLPSpanExporter(endpoint=endpoint)
tracer_provider.add_span_processor(OpenInferenceSpanProcessor())
tracer_provider.add_span_processor(SimpleSpanProcessor(exporter))


# Define your Pydantic model
class LocationModel(BaseModel):
    city: str
    country: str

instrumentation = InstrumentationSettings(version=2)

# Create and configure the agent
model = OpenAIModel("gpt-4", provider=OpenAIProvider())
agent = Agent(model, output_type=LocationModel, instrument=instrumentation)

# Run the agent
result = agent.run_sync("The windy city in the US of A.")
print(result)

This example:

1. Sets up OpenTelemetry tracing with Phoenix
2. Defines a simple Pydantic model for location data
3. Creates a PydanticAI agent with instrumentation enabled
4. Runs a query and gets structured output

The traces will be visible in the Phoenix UI at http://localhost:6006.

More Info

• More info on OpenInference and Phoenix
• More info on OpenInference and Arize AX
• How to customize spans to track sessions, metadata, etc.
• How to account for private information and span payload customization