Cerebras Tracing

Cerebras Inference exposes an OpenAI-compatible API for high-speed LLM inference. Set the OpenAI client’s base_url to Cerebras and use openinference-instrumentation-openai to send request, response, token, latency, and error spans to Phoenix.

This is OpenAI SDK instrumentation pointed at Cerebras’ OpenAI-compatible endpoint. It is not a separate Cerebras-specific instrumentor.

Install

pip install arize-phoenix-otel openinference-instrumentation-openai openai

Setup

Add your Cerebras API key and the model you want to call, along with your Phoenix connection details, as environment variables:

export CEREBRAS_API_KEY="<your-cerebras-api-key>"
export CEREBRAS_MODEL="<your-cerebras-model-id>"
export PHOENIX_COLLECTOR_ENDPOINT="<your-phoenix-collector-endpoint>"  # use http://localhost:6006 for local Phoenix
export PHOENIX_API_KEY="<your-phoenix-api-key>"  # required for Phoenix Cloud or authenticated Phoenix

Connect your application to Phoenix with the register function:

Run Cerebras

import os
import openai

client = openai.OpenAI(
    base_url="https://api.cerebras.ai/v1",
    api_key=os.environ["CEREBRAS_API_KEY"],
)

response = client.chat.completions.create(
    model=os.environ["CEREBRAS_MODEL"],
    messages=[
        {
            "role": "user",
            "content": "Summarize why fast inference still needs observability.",
        },
    ],
)
print(response.choices[0].message.content)

Observe

Now that you have tracing set up, all invocations of the OpenAI client pointed at Cerebras will be streamed to your running Phoenix for observability and evaluation. Each request appears as a ChatCompletion LLM span with the prompt, response, model name, token usage, and latency.

Common Issues

No traces in Phoenix: Confirm PHOENIX_COLLECTOR_ENDPOINT (and PHOENIX_API_KEY if your Phoenix requires one) is set in the same shell that runs your app
Cerebras spans missing: Call register() before you create the OpenAI client, and make sure openinference-instrumentation-openai is installed so auto_instrument=True picks it up
401 from Cerebras: Use your Cerebras API key, not your OpenAI key
Model not found: Confirm CEREBRAS_MODEL matches a model available in your Cerebras account
Base URL: Ensure you’re using https://api.cerebras.ai/v1 as the base URL

Developer Tools

LLM Providers

TypeScript

Python

Java

.NET

Platform

Vector Databases

Sandboxes

Evaluation Integrations

Coding Agents

Cerebras Tracing

Install

Setup

Run Cerebras

Observe

Common Issues

Resources

Cerebras Inference Documentation

OpenInference OpenAI Instrumentation

​Install

​Setup

​Run Cerebras

​Observe

​Common Issues

​Resources

Cerebras Inference Documentation

OpenInference OpenAI Instrumentation

Install

Setup

Run Cerebras

Observe

Common Issues

Resources