Navigating the OpenAI Code Maze at Microsoft

Someone says “check the code in Mumford under Sorento in project-argos” and you nod like that’s a normal sentence. It’s not. The way Microsoft organizes access to OpenAI code involves at least three naming layers, two hosting platforms, and a concept called “tenting” that has nothing to do with camping.

Here’s the decoder ring.

The Big Picture

Microsoft and OpenAI share code. But you can’t just git clone from OpenAI’s GitHub – there’s an access control layer called tenting. Think of tents as security perimeters. You get approved for a tent, and that tent gives you visibility into specific repos.

All the tented code lives in Azure DevOps (ADO), not GitHub. The ADO organization is called project-argos. That’s your entry point for everything.

The Three Tents

There are three active tents. Two of them are straightforward. One is nested inside another, because of course it is.

The confusing part: Mumford is not a separate tent. It’s a project nested inside Sorento. When you get access to Sorento, you get access to Mumford. People talk about them like they’re peers, but architecturally, Mumford lives under Sorento’s umbrella.

You might also hear about Cresco-uni – that’s deprecated. Ignore it.

Where the Monorepo Actually Lives

OpenAI’s GitHub monorepo (github.com/openai/openai) is mirrored into ADO as:

dev.azure.com/project-argos/Mumford/_git/topiary-msft-openai-monorepo

That’s where oaipkg lives (oaipackaging/oaipkg/), along with everything else from the OAI monorepo. You don’t need separate GitHub access – the ADO mirror is the sanctioned path.

ADO URL Anatomy

If you’re used to GitHub, ADO URLs look alien. Here’s the breakdown:

https://dev.azure.com/project-argos/Mumford/_git/topiary-msft-openai-monorepo
        \_____________/ \____________/ \_____/ \___/ \____________________________/
              |              |           |      |              |
            Host        Organization  Project Route         Repo

• Host: dev.azure.com – Azure DevOps
• Organization: project-argos – the MS-OAI shared org
• Project: Mumford – the tented project (nested in Sorento)
• Route: _git – repo browser. Other routes: _build (pipelines), _wiki, _workitems
• Repo: topiary-msft-openai-monorepo – the actual repo name

In branch URLs, you’ll see GBmaster – the GB prefix means “git branch,” so GBmaster = branch master.

Cloning a Repo from ADO

This is where people get stuck. ADO isn’t GitHub – git clone works, but auth is different.

Step 1: Install Git Credential Manager

If you’re on macOS and installed Git via Homebrew, you likely already have it. Check:

git credential-manager --version

If not installed:

brew install --cask git-credential-manager

Step 2: Clone

git clone https://dev.azure.com/project-argos/Mumford/_git/topiary-msft-openai-monorepo

The first time you clone, Git Credential Manager will pop up a browser window asking you to authenticate with your Microsoft account. Sign in with your @microsoft.com credentials. It caches the token, so subsequent operations won’t prompt again.

Alternative: Personal Access Token (PAT)

If you prefer not to use the browser flow, or you’re in a headless environment:

1. Go to https://dev.azure.com/project-argos/_usersSettings/tokens
2. Generate a new token with Code (Read) scope
3. Clone with the token embedded:

git clone https://<your-pat>@dev.azure.com/project-argos/Mumford/_git/topiary-msft-openai-monorepo

Or set it up once so you don’t paste tokens into URLs:

git config --global credential.https://dev.azure.com.helper manager

Heads Up

The monorepo is large. Like, really large. The initial clone will take a while. Consider a shallow clone if you just need recent history:

git clone --depth 1 https://dev.azure.com/project-argos/Mumford/_git/topiary-msft-openai-monorepo

What About “Orange”?

You’ll hear “Orange” mentioned alongside the tents. It’s not a tent – it’s a separate compute access onboarding for running workloads on OpenAI infrastructure. Different process, different wiki (project-argos/Penny/_wiki). Don’t confuse it with code access.

Other ADO Orgs You Might See

project-argos isn’t the only ADO org at Microsoft. You might bump into:

Same URL pattern, different org name. Don’t mix them up.

How to Get Access

Post in #openai-tenting-requests on Slack. Mention which tents you need (Sorento, Mimco, or both – Mumford comes with Sorento). Rahul Rathi manages the process. Expect a day or two for approval.

The Naming, Explained

Why “Sorento”? “Mumford”? “Mimco”? “Argos”?

No idea. They’re codenames. They don’t mean anything descriptive. This is just how large orgs name internal projects – random words that won’t collide with product names. Don’t try to derive meaning from them. Just memorize the mapping.

Quick Reference