OpenAI LLM analytics installation

  1. Install dependencies

    Required
    Full working examples

    See the complete Node.js and Python examples on GitHub. If you're using the PostHog SDK wrapper instead of OpenTelemetry, see the Node.js wrapper and Python wrapper examples.

    Install the OpenTelemetry SDK, the OpenAI instrumentation, and the OpenAI SDK.

    pip install openai opentelemetry-sdk opentelemetry-exporter-otlp-proto-http opentelemetry-instrumentation-openai-v2
  2. Set up OpenTelemetry tracing

    Required

    Configure OpenTelemetry to auto-instrument OpenAI SDK calls and export traces to PostHog. PostHog converts gen_ai.* spans into $ai_generation events automatically.

    from opentelemetry import trace
    from opentelemetry.sdk.trace import TracerProvider
    from opentelemetry.sdk.trace.export import SimpleSpanProcessor
    from opentelemetry.sdk.resources import Resource, SERVICE_NAME
    from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
    from opentelemetry.instrumentation.openai_v2 import OpenAIInstrumentor
    resource = Resource(attributes={
    SERVICE_NAME: "my-app",
    "posthog.distinct_id": "user_123", # optional: identifies the user in PostHog
    "foo": "bar", # custom properties are passed through
    })
    exporter = OTLPSpanExporter(
    endpoint="https://us.i.posthog.com/i/v0/ai/otel",
    headers={"Authorization": "Bearer <ph_project_token>"},
    )
    provider = TracerProvider(resource=resource)
    provider.add_span_processor(SimpleSpanProcessor(exporter))
    trace.set_tracer_provider(provider)
    OpenAIInstrumentor().instrument()
  3. Call OpenAI LLMs

    Required

    Now, when you use the OpenAI SDK to call OpenAI, PostHog automatically captures $ai_generation events via the OpenTelemetry instrumentation.

    import openai
    client = openai.OpenAI(
    api_key="your_openai_api_key",
    )
    response = client.responses.create(
    model="gpt-5-mini",
    input=[
    {"role": "user", "content": "Tell me a fun fact about hedgehogs"}
    ],
    )
    print(response.output_text)

    Note: If you want to capture LLM events anonymously, omit the posthog.distinct_id resource attribute. See our docs on anonymous vs identified events to learn more.

    You can expect captured $ai_generation events to have the following properties:

  4. Capture embeddings

    Optional

    PostHog can also capture embedding generations as $ai_embedding events. The OpenTelemetry instrumentation automatically captures these when you use the embeddings API:

    response = client.embeddings.create(
    input="The quick brown fox",
    model="text-embedding-3-small",
    )
  5. Verify traces and generations

    Recommended
    Confirm LLM events are being sent to PostHog

    Let's make sure LLM events are being captured and sent to PostHog. Under LLM analytics, you should see rows of data appear in the Traces and Generations tabs.


    LLM generations in PostHog
    Check for LLM events in PostHog
  6. Next steps

    Recommended

    Now that you're capturing AI conversations, continue with the resources below to learn what else LLM Analytics enables within the PostHog platform.

    ResourceDescription
    BasicsLearn the basics of how LLM calls become events in PostHog.
    GenerationsRead about the $ai_generation event and its properties.
    TracesExplore the trace hierarchy and how to use it to debug LLM calls.
    SpansReview spans and their role in representing individual operations.
    Anaylze LLM performanceLearn how to create dashboards to analyze LLM performance.

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