Introduction

"From watching agents code to managing the work itself."

This is the No.57 article in the "One Open Source Project a Day" series. Today, we are exploring Symphony .

In the previous article on OpenHands , we saw an all-in-one GUI for AI software engineers. Symphony , released by OpenAI, is the official reference for "how to run AI agents at scale in a professional engineering team." It is more than just a tool; it is a philosophical blueprint for Agentic Ops . With Symphony, OpenAI introduces the concept of Harness Engineering —the art of building a robust external framework to steer, drive, and monitor autonomous AI agents.

What You Will Learn

What is "Harness Engineering"?

How Symphony uses WORKFLOW.md for versioned policy management of AI agents.

Why workspace isolation is the key to scaling agentic runs.

Why OpenAI chose Elixir/OTP for their reference orchestrator implementation.

Prerequisites

Basic understanding of AI agent workflows.

Familiarity with project management tools like…