A guide for generating or editing bitmap images, such as illustrations, mockups, photos, textures, and transparent cutouts.

Use it when a project needs new visual assets, edited images, UI mockups, or batches of generated images.

It explains which image-generation method to use and how to handle common cases such as transparent backgrounds.

imagegen — Skill by chenrui333

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods

npx agentmods add skills/chenrui333/codex-docs/imagegen

Any agent

npx skills add chenrui333/codex-docs --skill imagegen

Clone the repo

git clone --depth 1 https://github.com/chenrui333/codex-docs

Made for: Claude Code, Codex.

Per session 113 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,949 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin 89% copy Near-identical to another mod in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5	$0.00113	$0.04949
Opus 5	$0.00056	$0.02475
Sonnet 5	$0.00023	$0.00990
Haiku 4.5	$0.00011	$0.00495

Measured 2d ago against content hash 96085ac4e883, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

imagegen scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/image_gen.py, scripts/remove_chroma_key.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

89% identical to imagegen — 12 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

dot_codex/skills/dot_system/imagegen/SKILL.md · 324 lines

How it starts

The opening of the file, as written. The whole thing — 324 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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).

Top-level modes and rules

This skill has exactly two top-level modes:

Default built-in tool mode (preferred): built-in image_gen tool for image generation, editing, and transparent-image requests. Does not require OPENAI_API_KEY.
Fallback CLI mode: scripts/image_gen.py CLI. Use when the user explicitly asks for or confirms the CLI/API/model path. 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.
For transparent images, ask built-in image_gen for a transparent background and preserve the generated alpha.
Never silently switch from built-in image_gen or CLI gpt-image-2 to CLI gpt-image-1.5; ask the user first unless they explicitly requested gpt-image-1.5.
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.

Built-in save-path policy:

In built-in tool mode, Codex saves generated images under $CODEX_HOME/* by default.
Do not describe or rely on OS temp as the default built-in destination.
Do not describe or rely on a destination-path argument (if any) on the built-in image_gen tool. If a specific location is needed, generate first and then move or copy the selected output from $CODEX_HOME/generated_images/....
Save-path precedence in built-in mode:
1. If the user names a destination, move or copy the selected output there.
2. If the image is meant for the current project, move or copy the final selected image into the workspace before finishing.
3. If the image is only for preview or brainstorming, render it inline; the underlying file can remain at the default $CODEX_HOME/* path.
Never leave a project-referenced asset only at the default $CODEX_HOME/* path.
Do not overwrite an existing asset unless the user explicitly asked for replacement; otherwise create a sibling versioned filename such as hero-v2.png or item-icon-edited.png.

Read the full file on GitHub · 324 lines

Files

What ships with it

11 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2d ago First seen · 324 lines · 113 tokens per session scan A 96085ac4e883

Subscribe to this mod's changes

imagegen is a skill published in the GitHub repository chenrui333/codex-docs (5 stars, last pushed 2d ago), licensed MIT. It adds 113 tokens to every session and 4,949 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. It is 89% identical to imagegen, differing in 12 lines, and is treated as a copy.

Creative and media codex codex-cli openai

imagegen

Generate or edit raster images when the task benefits from AI-created bitmap visuals such as photos, illustrations, textures, sprites, mockups, or transparent-background cutouts. Use when Codex should create a brand-new image, transform an existing image, or derive visual variants from references, and the output…

Kbediako/codex-termux-pocket · 113 tokens

imagegen

Getting it into your agent

What it costs to keep this loaded

Grade A, and why

Nothing flagged

This is a copy

How it starts

Image Generation Skill

Top-level modes and rules

What ships with it

What this file has done since we first saw it

Other skills, from other repositories

imagegen

emil-design-eng

image-generation

powerpoint

sherpa-onnx-tts

sag