Codex for Product Managers

Codex for product managers in a visual workspace.

Plan in markdown, mockup features, run Codex and Claude Code sessions, and review every change as a visual diff. Nimbalyst gives PMs one workspace instead of a terminal, an IDE, a model-provider app, and a pile of handoffs.

Download

Works with your existing Claude Code and Codex subscription or API key

Other downloads: Apple Silicon Mac Intel Mac Windows Linux

PMs need Codex, not developer-shaped tooling around it

Codex is useful for product work: PRDs, prototypes, mockups, competitive research, feedback analysis, tickets, and release notes. The problem is the interface PMs are usually handed. The terminal is built for engineers. The IDE is built for people editing code all day. OpenAI's Codex app is a provider-owned task surface, but it is not a visual workspace where PMs can directly edit mockups, specs, diagrams, and project files.

Nimbalyst gives Codex a higher-bandwidth PM workflow. Write specs in a real editor and watch every AI edit as a red and green diff. Render mockups and annotate them. Diagram flows. Work directly in the files that live with the repo. Run several agent sessions and see all of them on a board. The terminal and IDE are still there when engineering wants them, but PM work does not have to happen through developer tools or copied chat output.

Why Nimbalyst

What a PM gets beyond terminals, IDEs, and provider apps

Write PRDs, see every edit

Write PRDs, see every edit

Draft specs and plans in a WYSIWYG markdown editor. Let Codex draft or rewrite, then accept or reject each change as an inline red and green diff. No raw terminal scrollback or copy-paste from chat.

Mockups you can actually see

Mockups you can actually see

Ask an agent for a screen and it renders right in the workspace. Draw annotations on top, iterate, and the agent applies your notes. Prototype without leaving your plan.

Diagram flows and architecture

Diagram flows and architecture

Turn a paragraph into an Excalidraw diagram or a mind map, edited visually. Map user flows and system architecture next to the spec they belong to.

Review every change before it lands

Review every change before it lands

See exactly what an agent changed, file by file, in red and green. Approve, reject, or edit each change. You decide what ships.

Run several agents, track them all

Run several agents, track them all

Start multiple Codex and Claude Code sessions and see every one on a kanban board with status and phase. No bouncing between terminal tabs, IDE panels, and provider-app tasks.

Codex and Claude Code, side by side

Codex and Claude Code, side by side

Run OpenAI Codex and Claude Code in the same workspace and pick the best engine for each task, with shared diff review and session management.

Free, open source, your OpenAI access

The Nimbalyst desktop and iOS apps are MIT licensed and on GitHub. Nimbalyst uses your existing OpenAI access to run Codex, so there is nothing new to buy.

Comparison

Terminals, IDEs, and provider apps vs a PM workspace

Feature Terminal, IDE, or Codex app Nimbalyst
Writing PRDs and specs Terminal/IDE: raw markdown. Codex app: chat output you move elsewhere. WYSIWYG editor with red and green diff review
Mocking up a feature Terminal/IDE: generated files you have to preview elsewhere. Codex app: no first-class mockup editor. Rendered mockups you annotate and iterate on
Diagramming a flow Terminal/IDE: diagram text or extensions. Codex app: explanation, not a workspace file. Visual Excalidraw diagrams and mind maps
Reviewing agent changes Terminal: git diff. IDE: code diffs. Codex app: summaries and task output. File-by-file visual diff, accept or reject each
Working in project files Terminal/IDE assumes developer comfort. Codex app is mostly task and chat around files. Open, edit, render, and review the actual project files visually
Tracking the work Split across chat, tickets, IDE tasks, and notes Tracker items and kanban your agents keep updated
Running several agent tasks Terminal tabs, IDE agent panels, or provider-app task lists Session board with status and phase per agent
Prototyping in your repo Possible in developer tools; hard to review as a PM Git worktrees, hand engineering a real branch
Choice of agent Usually one provider or one tool surface at a time OpenAI Codex and Claude Code, pluggable
Getting started as a PM Either developer tooling or low-bandwidth chat Visual workspace for planning, mockups, review, and agent sessions
Cost Your OpenAI plan Free and open source, your OpenAI access

FAQ

Frequently asked questions

Can product managers use Codex outside developer-shaped tooling?
Yes. Nimbalyst runs OpenAI Codex in a visual workspace, so PMs can write PRDs, mock up features, run agent sessions, and review changes without making the terminal, IDE, or Codex app the center of the workflow. The developer tools are still available when engineering wants them, but the PM workflow happens in visual files, diffs, mockups, diagrams, and session cards.
What is the best way for a product manager to use OpenAI Codex?
Most PMs want the outcomes Codex produces, not a terminal, an IDE, or a chat transcript they have to move between tools. The most PM-friendly way to use it is inside a visual workspace like Nimbalyst: plan in a markdown editor, render and annotate mockups, diagram flows, run one or more agent sessions on a kanban board, and review every change as a red and green diff before it lands.
How is Nimbalyst different from the Codex app?
The Codex app is useful for running provider-owned Codex tasks, but it is not a visual workspace for directly editing project files. Nimbalyst keeps PRDs, mockups, diagrams, code, data, diffs, trackers, and session history together, so there is less switching and higher bandwidth between PM intent and agent output.
Do I need to know how to code to use Nimbalyst?
No. Nimbalyst is designed for the plan, mockup, prototype, and review loop that product managers already run. You describe what you want in plain language, the agent does the work, and you review the results visually. Reading a diff is like reviewing tracked changes in a document.
How is this different from Lovable, Bolt, or v0?
Those tools build standalone demos on their own hosted infrastructure. Nimbalyst runs coding agents against your team's actual repository, with its real design system and history, and produces a reviewable branch engineering can pick up. Different jobs, and many PMs use both.
Does Nimbalyst work with my ChatGPT plan or OpenAI API key?
Yes. Nimbalyst uses your existing OpenAI access to run Codex, whether that is a ChatGPT plan that includes Codex or an OpenAI API key. There is no separate subscription to buy, and for Claude Code you bring your own Anthropic access.
Can I use Codex and Claude Code together?
Yes. Nimbalyst runs OpenAI Codex and Claude Code in the same workspace. You can start a session with either engine, run them side by side, and use the same diff review and session management for both.
How do I go from a PRD to a working prototype?
Write the PRD in the markdown editor, ask an agent to mockup the screens, iterate on the mockup with annotations, then run a coding session in a git worktree to turn it into a working prototype in your repo. Review the change as a visual diff and hand engineering the branch.
Is Nimbalyst free and open source?
Yes. The Nimbalyst desktop and iOS apps are free for individual use, MIT licensed, and the full source is on GitHub. You can read every line, run it locally, and fork it.

Learn More

Related guides and comparisons

AI Tools for Product Managers

How product managers plan, mockup, and ship with coding agents in Nimbalyst.

Claude Code for Product Managers Guide

The same visual workflow with Claude Code as the engine.

Codex for Product Managers Guide

The full walkthrough: PRDs, mockups, prototypes, and reviews with Codex in a visual workspace.

Codex GUI & Visual Workspace

The workspace layer around Codex: sessions, visual editors, and diff review.

Codex Desktop App

The open-source Codex desktop app for macOS, Windows, and Linux.

Vibe Coding

Describe what you want and watch a working prototype appear, then keep it in your repo.

Visual Editor for Claude Code and Codex

Inline AI diffs across markdown, mockups, diagrams, code, and data models.

UI Mockups

Generate, annotate, and iterate on interface mockups with an agent.

Feature Planning

Turn an idea into a structured plan the agent and the team can both work from.

Nimbalyst is the open-source visual workspace for building with Codex, Claude Code, and more

Download

Works with your existing Claude Code and Codex subscription or API key

Other downloads: Apple Silicon Mac Intel Mac Windows Linux