codex-image — gpt-image-2 via Codex OAuth subscription

Overview

Images are generated by gpt-image-2 through the Codex/ChatGPT OAuth subscription (token from ~/.codex/auth.json, created by codex login). No API key, no per-image cost — quota is shared with the Codex subscription.

Common misconception (documented agent failure): "Codex is text-only, image generation needs OPENAIAPIKEY / DALL-E." Wrong. The Codex backend (chatgpt.com/backend-api/codex) serves the image_generation tool over the Responses API; host model gpt-5.5 invokes it, gpt-image-2 renders.

Note: the Codex Claude Code plugin (openai/codex-plugin-cc) does NOT generate images — its role is review/architecture. This skill's script bypasses the plugin and talks to the Codex backend directly.

Setup (once)

Prerequisite — connect Codex first (this is how you get the token). The skill generates using the subscription OAuth token stored in ~/.codex/auth.json. To obtain that token you authenticate Codex once: install the Codex plugin and connect it to Claude Code (or use the Codex CLI directly), then log in — the login writes your subscription token to ~/.codex/auth.json. Only after Codex is connected and the token exists does generation work: scripts/run.sh reads that token and calls the Codex backend. Note: the Codex plugin's role is to connect Codex and produce the token — it does not itself render images; the rendering is done by this skill's own script over the Responses API.

1. Install the Codex CLI: npm install -g @openai/codex
2. Log in with your ChatGPT Plus/Pro (or Codex) subscription, not an API key: codex login — on a headless server use codex login --device-auth (gives a link + code you confirm from your phone). This writes the OAuth token to ~/.codex/auth.json.
3. The Python openai SDK is bootstrapped automatically by scripts/run.sh into the skill's own venv — nothing to install by hand.

Quick reference

# self-contained launcher — uses the skill's own venv, bootstraps it if missing
scripts/run.sh "prompt in English" [quality] [aspect] [ref1.png ... ref5.png]

Reference E2E verified: avatar character correctly transferred into a new scene (technique from ningzimu/codex-gpt-image, audited — talks only to chatgpt.com/auth.openai.com).

Prompt in English works best. Generation is slow — for high use a background call.

Hard constraints (violating any → HTTP 400 or wrong path)

1. References: max 5 images, as content blocks. {"type":"inputimage","imageurl":"data:<mime>;base64,...","detail":"auto"} placed NEXT TO input_text in the same user message. There is no seed parameter — for strict reproducibility a paid API (fal.ai FLUX) is still the better tool; for character/style/logo transfer this works.
2. Never client.images.generate() / Images API — that is the API-key path, the OAuth subscription rejects it. Only Responses API + tool imagegeneration (+ toolchoice={"type":"image_generation"} so the host model draws immediately).
3. stream=True and store=False are mandatory — otherwise HTTP 400 from the Codex backend.
4. input must be a LIST of message objects, not a bare string.
5. Auth: tokens.accesstoken (+ tokens.accountid → chatgpt-account-id header) from ~/.codex/auth.json. Required headers: OpenAI-Beta: responses=experimental, originator: codexclirs.

Troubleshooting

When NOT to use

• Deterministic graphics (avatars, banners, diagrams with exact typography/brand colors): hand-author SVG → render PNG via @resvg/resvg-js. A model will not hit exact brand colors or spell long headlines reliably.
• Reference-image / character-consistent pipelines: needs a paid image API (e.g. fal.ai FLUX), not this skill.

The skill is fully self-contained (script + own .venv, auto-bootstrapped by run.sh). E2E verified: low/square PNG generated via run.sh.