Eight arms.One objective.

OTTO is an independent engineering workflow for Codex. Invoke it once and it selects the right path to understand, plan, build, verify, recover, and ship your work with evidence.

Request beta access See the eight arms

Requesting access is free. No checkout or payment is taken on this page.

The operating system

The eight belongs to OTTO.

The arms describe how OTTO works. MarketBuilt is the marketplace product studio behind it, keeping the product, studio, and creator identities clear.

Understand

Find the real objective, constraints, and success conditions before work begins.

Engineer

Choose the smallest sound approach and make the important trade-offs explicit.

Build

Turn the chosen approach into focused, reviewable implementation work.

Observe & verify

Inspect the actual result and gather evidence that the whole experience works.

Guard

Keep risky actions, sensitive data, production changes, and approvals bounded.

Tool & recover

Use the available tools, diagnose failures, and recover without losing the thread.

Remember & coordinate

Preserve project context and keep work coherent across sessions and collaborators.

Ship & prove

Separate code, release, and live proof so completion claims stay trustworthy.

Private beta

A serious workflow layer, without another command language to remember.

OTTO is designed to travel between projects. The goal is one dependable invocation that applies the appropriate workflow, project instructions, safety boundaries, and proof standard automatically.

The current OTTO workflow package

Setup and project-profile guidance

Regular improvements during beta

Direct beta feedback with the maker

The marketplace studio

MarketBuilt

Marketplace systems and developer products by nature_boy.

See CardTrade Network

Built from marketplace engineering in the real world.

MarketBuilt builds marketplaces for real communities. OTTO grew out of the operating discipline used to build CardTrade Network: understand the product, protect the risky edges, use the right tools, inspect the actual experience, and keep release claims honest. It is now being shaped into a portable product for other projects.

OTTO is independent software and is not affiliated with, endorsed by, or sponsored by OpenAI. It is a workflow layer for compatible Codex environments, not a standalone AI model.