codex-imagegen-mcp

<p align="center"> <img src="docs/assets/hero.jpg" width="100%" alt="Codex ImageGen MCP — a 1930s travel-poster illustration: an enormous empty picture frame stands on a desert plain and frames a rising sun behind a peak, while a small train runs along a railway toward it"> </p> <p align="center"> <b>Codex's image generation, in every coding agent.</b><br> Generate and edit images from opencode, Claude Code, Codex, Cursor, VS Code, Gemini CLI and 20 more tools.<br> It runs on the ChatGPT plan you already pay for, so there's no API key and no per-image bill. </p> <p align="center"> <a href="https://www.npmjs.com/package/codex-imagegen-mcp"><img alt="npm version" src="https://img.shields.io/npm/v/codex-imagegen-mcp?style=flat-square&label=npm&color=A6553B"></a> <a href="https://github.com/ShalomObongo/codex-imagegen-mcp/actions/workflows/ci.yml"><img alt="CI status" src="https://img.shields.io/github/actions/workflow/status/ShalomObongo/codex-imagegen-mcp/ci.yml?branch=main&style=flat-square&label=CI"></a> <img alt="MCP stdio server" src="https://img.shields.io/badge/MCP-stdio%20server-2A2523?style=flat-square"> <img alt="Node 22 or newer" src="https://img.shields.io/badge/node-%E2%89%A5%2022-4E6E63?style=flat-square"> <img alt="Runs on your ChatGPT plan" src="https://img.shields.io/badge/ChatGPT%20plan-no%20API%20key-A6553B?style=flat-square"> <a href="LICENSE"><img alt="Apache-2.0 license" src="https://img.shields.io/badge/license-Apache--2.0-D9A05B?style=flat-square"></a> </p> <p align="center"> <a href="#quick-start"><b>Quick start</b></a> &nbsp;·&nbsp; <a href="#see-it-work"><b>See it work</b></a> &nbsp;·&nbsp; <a href="docs/TOOLS.md"><b>Tools</b></a> &nbsp;·&nbsp; <a href="docs/AUTH.md"><b>Sign-in</b></a> &nbsp;·&nbsp; <a href="docs/CLIENTS.md"><b>Clients</b></a> &nbsp;·&nbsp; <a href="docs/README.md"><b>All docs</b></a> </p> <br>

What it does

<table> <tr> <td width="33%" valign="top"> <img src="docs/assets/badges/signin.png" width="76" alt=""><br> <b>Your ChatGPT plan, not an API bill</b><br> Sign in once with ChatGPT, or reuse the sign-in Codex or opencode already has. Every image counts against the plan you already pay for. </td> <td width="33%" valign="top"> <img src="docs/assets/badges/clients.png" width="76" alt=""><br> <b>One installer, 25+ tools</b><br> <code>npx -y codex-imagegen-mcp install</code> finds your coding tools, shows every file it will touch, and edits only its own entry, keeping your comments. </td> <td width="33%" valign="top"> <img src="docs/assets/badges/transparency.png" width="76" alt=""><br> <b>Real transparent PNGs</b><br> Ask for <code>background: "transparent"</code> and get genuine alpha, checked on every file. A local chroma-key tool handles the rest. </td> </tr> <tr> <td width="33%" valign="top"> <img src="docs/assets/badges/aspect.png" width="76" alt=""><br> <b>Any canvas shape</b><br> Eleven aspect ratios from 21:9 to 9:21, and up to four variants of a prompt in parallel. </td> <td width="33%" valign="top"> <img src="docs/assets/badges/versions.png" width="76" alt=""><br> <b>Saves into your project, safely</b><br> Paths resolve to your workspace. An existing file is never overwritten; you get <code>hero-2.png</code> instead. </td> <td width="33%" valign="top"> <img src="docs/assets/badges/skill.png" width="76" alt=""><br> <b>Codex's own playbook</b><br> Ships the Codex app's <code>imagegen</code> skill as <code>imagegen-mcp</code>, adapted to these tools: prompt structure, edit invariants, save rules. </td> </tr> </table>

See it work

Two real opencode sessions in a scratch project. The images are exactly what came back:

<p align="center"> <img src="docs/assets/examples/real-session.jpg" width="100%" alt="Three real outputs: a transparent cartoon cactus sticker, the same sticker edited to wear a straw hat, and a 16:9 photographic hero of a cactus shop at sunset"> </p>

You: I need a sticker-style illustration of a cute cartoon cactus with a transparent background for this project. Save it as assets/cactus-sticker.png.

opencode · openai/gpt-5.5 loads the skill → imagegen_generate_image with background: "transparent" → "Saved assets/cactus-sticker.png, 1254×1254 PNG with a transparent background."

You: Make a 16:9 hero banner for the Cactus Shop landing page, and a variant of the sticker where the cactus wears a tiny straw hat. Keep everything else identical.

opencode · github-copilot/claude-sonnet-5 → imagegen_auth_status → imagegen_generate_image (aspect_ratio: "16:9") and imagegen_edit_image (images: ["assets/cactus-sticker.png"]) in parallel → both saved, the edit with "transparent background (alpha verified)".

One prompt, three canvases. aspect_ratio doesn't crop. The service composes a new picture for each shape:

<p align="center"> <img src="docs/assets/examples/aspect-ratios.jpg" width="100%" alt="The same travel-poster prompt of a train crossing a trestle bridge, generated at 1:1 (1254×1254), 16:9 (1672×941) and 9:16 (941×1672)"> </p>

A green screen becomes alpha on your machine. remove_background keys out a flat backdrop locally, with no network call and no quota:

<p align="center"> <img src="docs/assets/examples/remove-background.jpg" width="82%" alt="A striped hot-air balloon generated on a flat green backdrop, and the same balloon cut out onto a transparent checkerboard"> </p>

[!TIP] Every image in this repository was made with codex-imagegen-mcp itself. That covers the posters, the badges, the logo and the examples; the installer screenshots are real terminal output. The prompts and the art-direction record are in docs/assets.

Quick start

[!NOTE] You need Node.js 22+ and a ChatGPT plan that includes Codex (Plus, Pro, Business, Enterprise, Edu…). Codex image generation isn't available on the Free plan.

1 · Run the installer. npx fetches the latest release, so there's nothing to install first. The installer finds the coding tools on this machine, shows exactly which files it will create or change, and writes nothing until you confirm. Each config keeps its comments and formatting.

npx -y codex-imagegen-mcp install

<p align="center"> <img src="docs/assets/screens/installer-pick.png" width="100%" alt="The interactive installer: it found 10 of 25 supported tools and lists them grouped as terminal agents and editors, with the detected ones pre-selected"> </p>

The configs it writes start the server through npx as well; npm downloads it on first use and caches it. The installer also runs without questions, for scripts and dotfiles:

npx -y codex-imagegen-mcp install opencode cursor claude-code   # named tools (see --list)
npx -y codex-imagegen-mcp install --all --dry-run               # every detected tool, preview only

<details> <summary>Prefer a global install, the GitHub release, or a source checkout?</summary> <br>

A global install gives you the short codex-imagegen-mcp command. The installer then writes an absolute Node path instead of npx, which starts faster and doesn't depend on npx. That suits GUI apps like Claude Desktop and Cursor best:

npm install --global codex-imagegen-mcp
codex-imagegen-mcp install

The same package is attached to every GitHub release with a signed build-provenance attestation:

npm install --global https://github.com/ShalomObongo/codex-imagegen-mcp/releases/latest/download/codex-imagegen-mcp.tgz

From source:

git clone https://github.com/ShalomObongo/codex-imagegen-mcp.git && cd codex-imagegen-mcp
npm ci && npm run build
npm link                                  # puts `codex-imagegen-mcp` on your PATH

</details>

2 · Sign in with ChatGPT. The installer offers this at the end. Skip it if Codex or opencode is already signed in with ChatGPT.

npx -y codex-imagegen-mcp login           # opens the browser; use --device on a headless machine

3 · Check, then ask for pictures

npx -y codex-imagegen-mcp doctor          # Node, credentials, quota, and every tool it's installed in

you › Make a 16:9 hero image of a lighthouse at dusk and save it to assets/hero.png

[!TIP] From here on, commands use the short codex-imagegen-mcp from a global install. Without one, run them through npx the same way, for example npx -y codex-imagegen-mcp status.

How it works

sequenceDiagram
    autonumber
    participant A as Your agent<br/>(opencode, Claude Code…)
    participant M as imagegen MCP server<br/>(local · stdio)
    participant O as auth.openai.com
    participant C as chatgpt.com<br/>/backend-api/codex
    A->>M: generate_image {prompt, aspect_ratio, background}
    M->>M: pick credentials: own sign-in → Codex → opencode
    opt token expires within 5 minutes
        M->>O: refresh (under a cross-process lock)
        O-->>M: new access token + rotated refresh token
    end
    M->>C: POST /images/generations · Bearer token · ChatGPT-Account-ID
    loop every 5 s while the image renders
        M-->>A: progress notification (keeps the client's timeout alive)
    end
    C-->>M: PNG + usage headers
    M->>M: save without overwriting · verify alpha · build preview
    M-->>A: path, size, background + a 1024 px preview

It sends the same request as the image tool built into the Codex app, byte for byte. As OpenAI improves Codex's image model on the server, this server gets the same upgrade. How that was reverse-engineered →

Signing in

| You already have… | What happens | |---|---| | Codex (CLI or desktop app) signed in with ChatGPT | Works immediately. The server borrows ~/.codex/auth.json read-only. | | opencode signed in with OpenAI → ChatGPT Plus/Pro | Works immediately. It borrows ~/.local/share/opencode/auth.json read-only. | | Neither, or you want an independent sign-in | Run codex-imagegen-mcp login, or ask your agent to call the sign_in tool. |

codex-imagegen-mcp login            # browser → sign in → "You're signed in to Codex ImageGen MCP"
codex-imagegen-mcp login --device   # SSH/headless: enter a code at auth.openai.com/codex/device
codex-imagegen-mcp status           # account, plan, credential source and usage windows
codex-imagegen-mcp logout           # remove and revoke this tool's own sign-in

[!IMPORTANT] OpenAI refresh tokens are single-use. Borrowed sign-ins are therefore never refreshed or modified, so this server can't sign you out of Codex or opencode. Its own tokens are stored 0600 and refreshed under a lock shared by every server process. Authentication in depth →

Tools

| Tool | What it does | Key parameters | |---|---|---| | generate_image | A new image from a prompt | prompt · aspect_ratio · background · n · output_path | | edit_image | Edit images, or generate from 1–5 references | images · prompt · same options | | remove_background | Cut a flat backdrop out locally (no quota) | input_path · key_color (auto) · output_path | | auth_status | Sign-in, plan, credential source, usage windows | check_usage | | sign_in | Start a ChatGPT sign-in and return a link or code for you | method (browser · device) |

The server also exposes the resources imagegen://history, imagegen://images/{id} and imagegen://skill/*, and the prompts generate and edit. In opencode the prompts appear as /imagegen:generate and /imagegen:edit. Full reference →

From the terminal

The CLI uses the same engine as the MCP tools:

codex-imagegen-mcp generate "a watercolor fox in a snowy forest" -a 16:9 -o art/fox.png