image-gen-custom-skill/skill/image-gen-custom/SKILL.md

name, description

name	description
image-gen-custom	Generate images through any OpenAI-compatible Images API and save reproducible local PNG, JPEG, GIF, or WebP files. Use when Codex needs a custom image endpoint, explicit model and output path, or a dependable cross-platform image generation workflow.

Image Gen Custom

Use scripts/generate-image.ps1 on Windows or scripts/generate-image.sh on macOS/Linux. The wrappers create or reuse a private virtual environment; generation uses only the Python standard library. The Python core reads the API key, calls the Images API, validates the returned image, and writes it atomically.

& "$env:USERPROFILE\.codex\skills\image-gen-custom\scripts\generate-image.ps1" `
  -Prompt "A concise prompt..." `
  -Out "outputs\generated-image.png" `
  -Size "1024x1024" `
  -Quality "low" `
  -Force

"$HOME/.codex/skills/image-gen-custom/scripts/generate-image.sh" \
  --prompt "A concise prompt..." \
  --out outputs/generated-image.png \
  --size 1024x1024 \
  --quality low \
  --force

Credentials

Run the matching configure wrapper once. It prompts for the API base URL first, then prompts for the key in visible text so you can paste it. On Windows, the key is saved in a DPAPI-protected local file; on macOS and Linux, it uses the platform credential store.

& "$env:USERPROFILE\.codex\skills\image-gen-custom\scripts\configure.ps1"

"$HOME/.codex/skills/image-gen-custom/scripts/configure.sh"

The URL and Windows key file are saved under the local Codex shared configuration folder. The normal image command then needs no URL argument. An explicit -BaseUrl on the image command still overrides the saved value.

Set OPENAI_API_KEY instead when an ephemeral environment variable is preferred. Set OPENAI_BASE_URL for a custom OpenAI-compatible root; /v1 is appended when omitted. Never put a key in SKILL.md, scripts, shell history, command arguments, ZIP files, or source control.

Options and behavior

• Default model: gpt-image-2; use -Model or --model to override it.
• Use low quality for drafts and high quality for final images.
• Accept b64_json and absolute HTTP(S) URL responses; URL downloads are capped at 50 MB and checked for image signatures.
• Use CODEX_IMAGEGEN_VENV to choose the private virtual environment location.
• Use CODEX_IMAGEGEN_PYTHON to choose the Python executable used to bootstrap that environment.
• Report the concrete failure category without exposing credentials: missing runtime/dependency, keyring or authentication, network/permission, unsupported model/endpoint, quota, response parsing, download, or output writing.

Install a shared package

Extract the package and run scripts/install-skill.ps1 on Windows or scripts/install-skill.sh on macOS/Linux. Add -Force or --force only when updating an existing installation; the installer never overwrites the destination's keyring data or any local secret file. Start a new Codex task after installation.