Velvet

Velvet: A Developer Gateway for AI Feature Analysis (Now Part of Arize)

What was Velvet? Velvet was a developer gateway designed to analyze, evaluate, and monitor AI-powered features. It enabled developers to gain insights into the performance and behavior of their AI models in real-time.

Acquisition by Arize

In 2025, Velvet was acquired by Arize, an enterprise platform focused on AI evaluation and observability. This acquisition brought together Velvet's developer-centric approach with Arize's robust platform, aiming to accelerate the adoption of Arize's unified AI platform. Emma and Chris, the founders of Velvet, joined Arize as part of the acquisition.

Arize: Unified Observability and Evaluation Platform for AI

What is Arize? Arize is a comprehensive platform that helps accelerate the development of AI applications and agents, then perfects them in production. It offers unified observability and evaluation capabilities, ensuring AI models perform optimally.

Key Features of Arize:

• AI Evaluation: Evaluate the performance of AI models to ensure accuracy and reliability.
• Observability: Monitor AI models in real-time to identify and address any issues that may arise.
• Unified Platform: A single platform for all AI evaluation and observability needs.

Why Choose Arize?

Arize provides a unified solution for AI evaluation and observability, helping teams accelerate development, improve model performance, and ensure reliability in production.

How does Arize work?

Arize's platform provides tools for:

• Model Monitoring: Real-time tracking of model performance metrics.
• Root Cause Analysis: Tools to identify the underlying causes of model performance issues.
• Performance Evaluation: Comprehensive evaluation of model performance across various metrics.

Phoenix: Open-Source LLM Tracing and Evaluation

What is Phoenix? Phoenix is an open-source tool for LLM (Large Language Model) tracing and evaluation. It's designed to help developers accelerate AI development by providing seamless evaluation, experimentation, and optimization of AI applications in real time.

Key Features of Phoenix:

• LLM Tracing: Track the behavior of LLMs to understand how they are processing information.
• Evaluation: Evaluate the performance of LLMs to ensure accuracy and reliability.
• Open Source: A community-driven tool that is free to use and modify.

LiteLLM: LLM Gateway

What is LiteLLM? LiteLLM is an LLM Gateway that provides model access, fallbacks, and spend tracking across 100+ LLMs. It uses the OpenAI format and can be used as a platform or deployed open source.

Key Features of LiteLLM:

• Model Access: Access to a wide range of LLMs through a single gateway.
• Fallbacks: Automatic fallbacks to ensure that AI applications remain available even if one model fails.
• Spend Tracking: Track spending across different LLMs to optimize costs.

Use Cases for LiteLLM:

• AI Application Development: Simplify the process of building AI applications by providing access to a wide range of LLMs.
• Cost Optimization: Optimize costs by tracking spending across different LLMs.

Who is Arize for?

Arize is for data scientists, machine learning engineers, and AI developers who need to evaluate and monitor their AI models in production. It provides a unified platform for AI evaluation and observability, helping teams accelerate development, improve model performance, and ensure reliability.

Best way to monitor AI Models?

The best way to monitor AI models involves using a comprehensive platform like Arize that provides real-time tracking of model performance, root cause analysis tools, and performance evaluation metrics. Open source tools like Phoenix and LiteLLM provide more focused functionality for LLM tracing and management.