imagegen

Image Generation Skill

Generates or edits images for the current project (for example website assets, game assets, UI mockups, product mockups, wireframes, logo design, photorealistic images, or infographics).

Host routing

Resolve this before applying the built-in-tool instructions below:

• Codex: use the built-in image_gen workflow when it is exposed. Preserve the Codex save-path, view_image, chroma-key helper, confirmation, and CLI fallback rules below.
• Claude Code, including GLM Coding Plan sessions: the GLM endpoint does not provide Codex's built-in image_gen tool. Use an image-generation MCP or tool only when it appears in the active Claude Code tool list. Otherwise, offer the bundled OpenAI CLI fallback only after explicit user approval and the normal local OPENAI_API_KEY setup; if neither route is available, stop with a prompt/manual handoff.
• GitHub Copilot: use a host-exposed image tool or the approved CLI fallback. Do not invent Codex paths or tool names.

All later references to the "built-in" path are conditional on this host check. Do not infer image capability from the model name or API endpoint.

Top-level modes and rules

This skill has exactly two top-level modes:

• Host image-tool mode (preferred when exposed): Codex built-in image_gen, or an equivalent active host tool that supports the requested operation. Codex's built-in path does not require OPENAI_API_KEY.
• Fallback CLI mode: scripts/image_gen.py CLI. Use when the user explicitly asks for the CLI/API/model path, or after the user explicitly confirms a true model-native transparency fallback with gpt-image-1.5. Requires OPENAI_API_KEY.

Within CLI fallback, the CLI exposes three subcommands:

• generate
• edit
• generate-batch

Rules:

• Use the built-in image_gen tool by default for normal image generation and editing requests.
• Do not switch to CLI fallback for ordinary quality, size, or file-path control.
• If the user explicitly asks for a transparent image/background, stay on built-in image_gen first: prompt for a flat removable chroma-key background, then remove it locally with the installed helper at $CODEX_HOME/skills/.system/imagegen/scripts/remove_chroma_key.py.
• Never silently switch from built-in image_gen or CLI gpt-image-2 to CLI gpt-image-1.5. Treat this as a model/path downgrade and ask the user before doing it, unless the user has already explicitly requested gpt-image-1.5, scripts/image_gen.py, or CLI fallback.
• If a transparent request appears too complex for clean chroma-key removal, asks for true/native transparency, or local removal fails validation, explain that true transparency requires CLI gpt-image-1.5 --background transparent --output-format png because gpt-image-2 does not support background=transparent, then ask whether to proceed. Run the CLI fallback only after the user confirms.
• The word batch by itself does not mean CLI fallback. If the user asks for many assets or says to batch-generate assets without explicitly asking for CLI/API/model controls, stay on the built-in path and issue one built-in call per requested asset or variant.
• If the built-in tool fails or is unavailable, tell the user the CLI fallback exists and that it requires OPENAI_API_KEY. Proceed only if the user explicitly asks for that fallback.
• If the user explicitly asks for CLI mode, use the bundled scripts/image_gen.py workflow. Do not create one-off SDK runners.
• Never modify scripts/image_gen.py. If something is missing, ask the user before doing anything else.