codex-image

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Generate images using OpenAI's Codex backend API with gpt-image-2 tool. Use when the user asks to generate images via Codex, ChatGPT image generation, or gpt-image-2. Triggers on "codex image", "codex generate", "gpt-image", "chatgpt generate image". Token is auto-fetched from chatgpt.com session — no manual token setup needed.

QUICK START

How to use this skill

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Open your project in Codex.
Copy the prompt below and paste it into your agent.
Review the proposed files and risks before you approve installation.

Prompt to paste

I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/OpenMinis/MinisSkills/blob/HEAD/codex-image/SKILL.md

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First, summarize what it does, its dependencies, license status if identifiable, and any risks. Show the exact files you propose to add under .agents/skills/codex-image/. Do not write files or run scripts until I approve.

After I approve, install the complete skill folder, including required referenced files, into that project location. Verify it is discoverable, then tell me its actual invocation name and how to use it. Do not claim it is installed until you have verified it.

Copying this prompt does not install or run the skill. Review third-party files before use. Codex skill guide

Codex Image Generation

Generate images via chatgpt.com/backend-api/codex/responses using the image_generation tool (gpt-image-2).

Requirements

A ChatGPT account (token is fetched automatically via browser session)
No manual token setup needed — the skill handles auth automatically

Auth Token Resolution (in order)

--token argument (CLI only)
CODEX_IMAGE_TOKEN environment variable
--token-file argument (CLI only)
~/.chatgpt_auth.json cache (valid for 8 hours)
Auto login flow — fetches from https://chatgpt.com/api/auth/session via minis-browser-use:
- If already logged in → token extracted and saved to cache immediately
- If not logged in → opens chatgpt.com/auth/login in the browser, then polls every 10s in a new tab for up to 5 minutes
- On success → saves token to ~/.chatgpt_auth.json (chmod 600, token + timestamp only)
- Token is never printed to stdout or logs — it stays in the cache file only

Usage

Text-to-image

python3 scripts/codex_image.py "a cute rabbit on a light background" \
  --output rabbit.png \
  --model gpt-5.4 \
  --effort low

Image-to-image / reference image

python3 scripts/codex_image_edit.py "turn this person into a cinematic iOS AI assistant portrait" \
  --image reference.jpg \
  --output portrait.png \
  --model gpt-5.4 \
  --effort low

codex_image_edit.py encodes the local reference image as a base64 data URL and sends it as multimodal input (input_text + input_image) to the same Codex responses endpoint, then asks the image_generation tool to create a new image from the reference.

Parameters

Parameter	Default	Description
`prompt`	(required)	Image description or edit instruction
`--image`	(edit only, required)	Local reference image path for image-to-image generation
`--output`	`codex_image.png` / `codex_image_edit.png`	Output file path
`--model`	`gpt-5.4`	Codex model
`--effort`	`low`	Reasoning effort: low/medium/high
`--token`	-	Access token directly (skips auto auth; text-to-image script only)
`--token-file`	-	File containing token (skips auto auth; text-to-image script only)

Output

JSON with success, path, size, revised_prompt on success.

Auth Script (standalone)

python3 scripts/get_auth.py

Returns JSON {"success": true, "source": "cache|session|login"} — the token itself is never printed to stdout. It is written only to ~/.chatgpt_auth.json (chmod 600, token + timestamp only, no PII). This prevents the token from appearing in shell logs, conversation context, or screenshots.

Workflow

Token: auto-resolved via get_auth.py:
- Already cached → use directly
- Already logged in (browser session) → extract immediately
- Not logged in → minis-open pops the ChatGPT login page to the user in foreground, then polls every 10s (up to 5 min) until login is detected
Construct the prompt from the user's request.
Run scripts/codex_image.py with appropriate arguments.
Send the generated image to the user.

Notes

Token is cached in ~/.chatgpt_auth.json for 8 hours (chmod 600, token + timestamp only — no PII stored).
Token is never printed to stdout or conversation context — always read from cache file internally.
The endpoint requires stream: true; the script handles SSE parsing internally.
Token is a ChatGPT session token, not an OpenAI API key. It expires and is refreshed automatically on next use.
Image generation uses gpt-image-2 under the hood with auto quality/size.
Token usage is split: main usage tracks text tokens, tool_usage.image_gen tracks image tokens separately.
This uses an internal/unofficial API endpoint. Availability may change.