Arize Phoenix

Arize Phoenix is an open-source AI observability platform designed for monitoring, evaluating, and improving LLM applications. It can be self-hosted or used via Phoenix Cloud.

Configuration

Phoenix Cloud

If you're using Phoenix Cloud, configure these environment variables:

PHOENIX_API_KEY="your-phoenix-api-key"
PHOENIX_COLLECTOR_ENDPOINT="your-phoenix-hostname"

Getting Your Credentials

1. Sign up for an Arize Phoenix account at app.phoenix.arize.com
2. Grab your API key from the Keys option on the left bar
3. Note your Phoenix hostname for the collector endpoint

Self-Hosted Phoenix

If you're running a self-hosted Phoenix instance, configure:

PHOENIX_COLLECTOR_ENDPOINT="http://localhost:6006"
# Optional: If authentication enabled
PHOENIX_API_KEY="your-api-key"

Installation

Install the necessary packages:

npm install @arizeai/openinference-mastra@^2.2.0

Implementation

Here's how to configure Mastra to use Phoenix with OpenTelemetry:

Phoenix Cloud Configuration

import { Mastra } from "@mastra/core";
import {
  OpenInferenceOTLPTraceExporter,
  isOpenInferenceSpan,
} from "@arizeai/openinference-mastra";

export const mastra = new Mastra({
  // ... other config
  telemetry: {
    serviceName: "my-mastra-app",
    enabled: true,
    export: {
      type: "custom",
      exporter: new OpenInferenceOTLPTraceExporter({
        url: process.env.PHOENIX_COLLECTOR_ENDPOINT!,
        headers: {
          Authorization: `Bearer ${process.env.PHOENIX_API_KEY}`,
        },
        spanFilter: isOpenInferenceSpan,
      }),
    },
  },
});

Self-Hosted Phoenix Configuration

import { Mastra } from "@mastra/core";
import {
  OpenInferenceOTLPTraceExporter,
  isOpenInferenceSpan,
} from "@arizeai/openinference-mastra";

export const mastra = new Mastra({
  // ... other config
  telemetry: {
    serviceName: "my-mastra-app",
    enabled: true,
    export: {
      type: "custom",
      exporter: new OpenInferenceOTLPTraceExporter({
        url: process.env.PHOENIX_COLLECTOR_ENDPOINT!,
        spanFilter: isOpenInferenceSpan,
      }),
    },
  },
});

What Gets Automatically Traced

Mastra's comprehensive tracing captures:

• Agent Operations: All agent generation, streaming, and interaction calls
• LLM Interactions: Complete model calls with input/output messages and metadata
• Tool Executions: Function calls made by agents with parameters and results
• Workflow Runs: Step-by-step workflow execution with timing and dependencies
• Memory Operations: Agent memory queries, updates, and retrieval operations

All traces follow OpenTelemetry standards and include relevant metadata such as model parameters, token usage, execution timing, and error details.

Dashboard

Once configured, you can view your traces and analytics in Phoenix:

• Phoenix Cloud: app.phoenix.arize.com
• Self-hosted: Your Phoenix instance URL (e.g., http://localhost:6006)

For self-hosting options, see the Phoenix self-hosting documentation.