Observability - Phaseo Docs

Most observability tools sit above the model client. Keep your tracing setup the same, then point the underlying OpenAI-compatible or Anthropic-compatible client at Phaseo.

Langfuse with OpenAI SDK

pip install langfuse openai

import os
from langfuse.openai import openai

client = openai.OpenAI(
    api_key=os.environ["PHASEO_API_KEY"],
    base_url="https://api.phaseo.app/v1",
)

response = client.responses.create(
    model="openai/gpt-5-nano",
    input="Reply with only: ok",
)

LangSmith with LangChain

Use the LangChain setup and enable LangSmith through the usual LangChain environment variables:

export LANGSMITH_TRACING=true
export LANGSMITH_API_KEY="your_langsmith_key"
export PHASEO_API_KEY="your_phaseo_key"

OpenTelemetry

If your framework emits OpenTelemetry spans, Phaseo does not require a special exporter. Add useful request context yourself:

model id
endpoint, such as responses or chat.completions
Phaseo request id from response metadata or logs
selected provider when response metadata is enabled

Notes

Do not send Phaseo API keys to observability tools as attributes.
If the observability library wraps the OpenAI SDK, configure the wrapped client with base_url: "https://api.phaseo.app/v1".
For LangChain traces, pair the tracing callback with the Phaseo ChatOpenAI configuration.

Last modified on October 18, 2026