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Arize

Using OpenRouter with Arize

Using Arize

Arize provides observability and tracing for LLM applications. Since OpenRouter uses the OpenAI API schema, you can utilize Arize’s OpenInference auto-instrumentation with the OpenAI SDK to automatically trace and monitor your OpenRouter API calls.

Installation

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

Prerequisites

  • OpenRouter account and API key
  • Arize account with Space ID and API Key

Why OpenRouter Works with Arize

Arize’s OpenInference auto-instrumentation works with OpenRouter because:

  1. OpenRouter provides a fully OpenAI-API-compatible endpoint - The /v1 endpoint mirrors OpenAI’s schema
  2. Reuse official OpenAI SDKs - Point the OpenAI client’s base_url to OpenRouter
  3. Automatic instrumentation - OpenInference hooks into OpenAI SDK calls seamlessly

Configuration

Set up your environment variables:

Environment Setup
1import os
2
3# Set your OpenRouter API key
4os.environ["OPENAI_API_KEY"] = "${API_KEY_REF}"

Simple LLM Call

Initialize Arize and instrument your OpenAI client to automatically trace OpenRouter calls:

Basic Integration
1from arize.otel import register
2from openinference.instrumentation.openai import OpenAIInstrumentor
3import openai
4
5# Initialize Arize and register the tracer provider
6tracer_provider = register(
7    space_id="your-space-id",
8    api_key="your-arize-api-key",
9    project_name="your-project-name",
10)
11
12# Instrument OpenAI SDK
13OpenAIInstrumentor().instrument(tracer_provider=tracer_provider)
14
15# Configure OpenAI client for OpenRouter
16client = openai.OpenAI(
17    base_url="https://openrouter.ai/api/v1",
18    api_key="your_openrouter_api_key",
19    default_headers={
20        "HTTP-Referer": "<YOUR_SITE_URL>",  # Optional: Your site URL
21        "X-Title": "<YOUR_SITE_NAME>",      # Optional: Your site name
22    }
23)
24
25# Make a traced chat completion request
26response = client.chat.completions.create(
27    model="meta-llama/llama-3.1-8b-instruct:free",
28    messages=[
29        {"role": "user", "content": "Write a haiku about observability."}
30    ],
31)
32
33# Print the assistant's reply
34print(response.choices[0].message.content)

What Gets Traced

All OpenRouter model calls are automatically traced and include:

  • Request/response data and timing
  • Model name and provider information
  • Token usage and cost data (when supported)
  • Error handling and debugging information

JavaScript/TypeScript Support

OpenInference also provides instrumentation for the OpenAI JavaScript/TypeScript SDK, which works with OpenRouter. For setup and examples, please refer to the OpenInference JavaScript examples for OpenAI.

Common Issues

  • API Key: Use your OpenRouter API key, not OpenAI’s
  • Model Names: Use exact model names from OpenRouter’s model list
  • Rate Limits: Check your OpenRouter dashboard for usage limits

Learn More