Singularity vs Codex: OpenAI’s app or an ADE that drives Codex

Codex is OpenAI’s coding agent. It lives in the Codex view of the ChatGPT desktop app, in the terminal through the Codex CLI, in VS Code and its forks through the IDE extension, and in the cloud through Codex Cloud. It ships with ChatGPT plans, so many developers already have it without paying for anything extra.

The real question is not “Codex or Singularity”, because Singularity can drive Codex as an agent provider. It is this: should you work inside the model vendor’s own app, or orchestrate the same agent from an Agentic Development Environment (ADE) built around tickets, a Kanban board and local Git integration? This comparison helps you decide based on how you actually work.

Comparison checked on 10 October 2026 against the official Codex (OpenAI) documentation and Singularity’s documentation. It compares workflows, not the speed or quality of generated code. Public prices are shown in USD/EUR as listed, excluding tax and usage, and may change.

In short

• Codex is a multi-surface agent (desktop app, CLI, IDE, cloud, web and mobile) tightly bound to OpenAI’s models and plans.
• Singularity is a desktop ADE: editor, terminal, Git client, LSP and a Kanban board where every ticket becomes an agent mission in its own worktree.
• Both isolate parallel work in Git worktrees; they differ in the unit of work (a conversation versus a tracked ticket) and in integration (branch and pull request versus a serialised local rebase).
• Singularity drives the Codex CLI installed on your machine, with your OpenAI account: you can keep Codex and orchestrate it alongside Claude Code, Copilot, Cursor, Gemini, Mistral or Ollama.
• Codex remains stronger for cloud work, GitHub pull request reviews and access from the web or a phone.

What Codex is

Since 9 July 2026, the former Codex app is part of the ChatGPT desktop app on macOS and Windows, with a Linux preview available since August 2026 for Ubuntu, Debian and Fedora. In that desktop app, Codex is a separate view next to Chat and Work, designed for running several projects and long-running jobs in parallel, with scheduled tasks.

The Codex CLI runs in the terminal on macOS, Linux and Windows; its openai/codex repository is published under the Apache-2.0 licence. You sign in with your ChatGPT account, set permissions with /permissions and pick the model with /model. The IDE extension works in VS Code and compatible editors (Cursor, Windsurf), with dedicated integrations for JetBrains and Xcode. Finally, Codex Cloud runs tasks in remote workspaces configured per environment (GitHub repositories, setup scripts, network access) that keep going while your computer sleeps.

For local parallelism, the app offers two modes: Local, your own checkout, and Worktree, a separate checkout Codex creates for background work. According to the worktree documentation, they are created under $CODEX_HOME/worktrees in detached HEAD; the “Hand off” button moves a chat and its code between Local and Worktree, and Codex keeps the 15 most recent managed worktrees by default. Codex can also spawn subagents in parallel.

Code review relies on /review, a commentable diff pane and GitHub pull request reviews with @codex review. Behaviour is configured with AGENTS.md, skills and plugins (skills, MCP, hooks) and a per-OS sandbox.

The models are OpenAI’s (GPT-6.1 Sol, Astra, GPT-6 Luna). On pricing, Codex is included in ChatGPT Free (quick tasks, subject to rollout), Go (USD 8/month), Plus (USD 20/month), Pro (from USD 100/month) and Business (USD 25 per user per month, USD 20 billed annually); Enterprise and Edu are quoted. Limits vary with the model and task, and extra credits can be bought. An API key, billed at API rates, works in the CLI and IDE without the cloud features.

Singularity at a glance

Singularity is a desktop ADE made by Meteor Factory: editor, native terminals, a full Git client, language servers, multi-project workspaces and a Kanban board that acts as the execution surface for agents. A ticket carries the description, priority, dependencies and agent configuration, then keeps the report and a short resolution. In worktree mode, each run works in its own worktree, then its commits are replayed onto the base with a rebase, in the order of an integration queue; the Review tab and auto-merge decide how much is automated.

It drives seven providers through their CLIs (Claude Code, Codex, Copilot, Cursor, Gemini, Mistral, Ollama) and includes no model subscription. The proprietary app is free and runs on macOS, Windows and Linux (installation); the Singularity Licence (EUR 24 per month per workstation, 14-day trial) only unlocks paid plugins such as Pipelines.

Comparison table

The same feature in both tools

Take a realistic task: add a CSV export to an invoice list, with a new API endpoint and a button in the UI, all covered by tests.

With Codex

In the Codex view, you start a chat in Worktree mode, then hand it the whole job, ask for two subagents, or open a second chat for the UI. In the review pane you comment on lines and request fixes, then “Create branch here”, commit, push and open a pull request; or you hand the work back to Local. A long task can go to Codex Cloud and come back as a pull request reviewed by @codex review. This is smooth for one or two chats; ordering the API and UI work is up to you.

With Singularity

You create a parent ticket, “Invoice CSV export”, with acceptance criteria, then two child tickets, “Export endpoint” and “Export button”, the second blocked by the first so it only starts once the endpoint is done and integrated. Codex can handle one, another provider the other. Each run works in its own worktree, shows its phase on the card and can ask a blocking question that you answer from the ticket.

At the end, the result is integrated by rebase or waits in the Review tab: per-file approval, notes on a selection, full or partial merge, or rerun with your notes. After a rebase, the agent must rerun the affected tests; green tests do not rule out a semantic conflict, so human review is still worthwhile.

Agents and parallelism: chats versus tickets

Both tools isolate parallel work in Git worktrees: Codex per chat, Singularity per ticket. In Codex, the chat carries the context, the diff and the follow-ups, which is natural for exploring and staying hands-on.

In Singularity, the ticket exists before the agent, outlives the run and keeps a record of each attempt. The scheduler picks the next ready ticket based on dependencies, priority and the concurrent-agent limit; a Pending ticket is waiting for an answer, a review, its children or the integration queue, and is never mistaken for a failure. With ten tasks across several repositories, that tracking is what matters most. Either way, every agent draws on your OpenAI plan’s limits; the concurrent-agent limit also keeps that quota in check.

Git, review and integration

Codex is branch- and pull-request-centric: push, open a PR, and continue the review on GitHub with Codex as a reviewer. Ideal if your team lives in pull requests.

Singularity integrates locally: a ticket’s commits are replayed onto the latest base with a rebase (linear history, no merge commits) and the integration queue serialises integrations for a project. If a conflict appears, the run stays available to resolve it. You then publish with the built-in Git client. The paid Pipelines plugin monitors GitHub Actions, GitLab CI and Azure DevOps and creates repair tickets from failures.

Where Codex is stronger

• Cloud work: Codex Cloud keeps tasks running while your computer sleeps, with configurable, reusable environments. Singularity runs agents on your machine.
• GitHub pull requests: automatic or on-demand reviews with @codex review, plus GitHub, Slack and Linear integrations.
• Surfaces: desktop app, CLI, IDE, web and mobile share one account, so you can pick work up elsewhere.
• OpenAI model integration: new models and modes land in the vendor’s own product first, with no adapter in between.
• One subscription: if you already pay for ChatGPT, Codex is included, and the CLI is open source.

Where Singularity stands out

• The ticket as the unit of work: priorities, dependencies, child tickets, daily or weekly schedules, explicit statuses and a short resolution on every card.
• Multiple providers: Codex, Claude Code, Copilot, Cursor, Gemini, Mistral and Ollama in one interface, with a model chosen per ticket and exclusions for automatic selection.
• Controlled local integration: rebase onto the base branch, an integration queue, per-file review with partial merge and rerun with annotations.
• A complete environment: CodeMirror editor, 31 language servers, native terminals, Git client and multi-repository workspaces, without leaving the app.
• A per-session MCP gateway: the agent reads its ticket, posts its phase, asks a question or creates a follow-up ticket, with access that expires with the session.

Can you use both?

Yes, and it is often the best option. Install the Codex CLI, run codex and sign in to your OpenAI account: Singularity then drives that CLI and exposes its settings (personality, approval policy, sandbox mode, reasoning effort and summary). Singularity does not upload your code by itself: data follows the same path as with the Codex CLI alone, whereas Codex Cloud clones the repository into a remote workspace.

A common split: the ChatGPT app and Codex Cloud for exploration, tasks started from your phone and PR reviews; Singularity for planned work, broken into tickets and integrated locally. Singularity does not replace OpenAI-only features (cloud, GitHub reviews, mobile). If you are also weighing Anthropic’s tool, read Singularity vs Claude Code.

Which tool should you choose?

• You mostly work alone, conversationally, on one repository: the Codex app or CLI is more than enough.
• Your team lives in GitHub and pull requests: Codex, with Codex Cloud and PR reviews, matches that flow.
• You delegate many tasks in parallel across several repositories: Singularity adds the board, dependencies and serialised integration.
• You want to compare or mix providers: Singularity, which orchestrates Codex among six others.
• You do not want code executed outside your machine: Codex locally or Singularity; avoid cloud tasks.

Trial protocol

1. Pick a real task that touches two layers (API and UI), with written acceptance criteria and existing tests.
2. In the Codex app, handle it in Worktree mode with one or two chats; note the time spent coordinating, reviewing and integrating.
3. Install Singularity, add the repository to a workspace and check that the Codex CLI responds from a terminal.
4. Create a parent ticket and two dependent child tickets, with Codex as the provider and auto-merge turned off.
5. Review both results in the Review tab, then compare Git history, quota usage and the number of manual interventions.

Frequently asked questions

Does Singularity replace my ChatGPT subscription?

No. Singularity includes no models. To use Codex in Singularity you need the Codex CLI signed in to your OpenAI account, and usage follows your ChatGPT plan’s limits or your API key billing.

Can I start Codex Cloud tasks from Singularity?

No. Singularity drives the Codex CLI locally, in the ticket’s worktree. Codex Cloud is started from OpenAI’s own surfaces.

Do I need a Singularity subscription to use Codex?

No. The app is free, agent providers included. The Singularity Licence is only for paid plugins such as Pipelines.

To go further, browse all Singularity comparisons, including Singularity vs Conductor, follow the getting started guide or download Singularity.