Nano Banana ASO

An agent skill for building premium, consistent App Store screenshot campaigns with Nano Banana Pro.

This skill helps an agent:

• analyze an app codebase for brand, claims, and differentiators
• decide which app screens should be captured
• write a layout plan before image generation
• lock a style anchor for consistency across the set
• generate advertisement-first App Store slides
• normalize exports to App Store-safe sizes
• build a contact sheet for review

Workflow

The skill is built around a specific sequence so the screenshot set stays consistent and App Store-safe:

1. Scan the codebase

   • inspect fonts, colors, onboarding copy, pricing language, differentiators, and supported claims
   • identify the app’s strongest user benefit and the real features worth selling

2. Decide the campaign story

   • turn the app into a 5 to 7 slide ad narrative
   • define what each slide should sell in one second

3. Ask for specific screenshots

   • tell the user exactly which screens to capture
   • specify what should be visible in each raw screenshot

4. Write a layout plan

   • lock campaign positioning, story spine, consistency spine, crop-safe rules, and export target
   • use the plan as the source of truth before any image generation starts

5. Convert copy into render-safe prompts

   • keep `` line breaks in planning docs only
   • translate final prompt copy into explicit multi-line headline blocks
   • explicitly tell the image model not to render literal `` characters
   • shorten text-heavy slides before pushing copy toward crop edges

6. Generate a style anchor

   • create slide 1 first with Nano Banana Pro
   • use it to define typography, background language, panel treatment, device treatment, and overall visual family
   • use it to test cropping, font treatment, CTA cues, and text density before the rest of the set is generated

7. Generate the rest of the set

   • create slides 2 to N as consistent variations of the approved anchor
   • reuse the findings from perfecting slide 1 so the later slides inherit proven spacing and typography rules
   • keep the screenshot or product visual as the main focus
   • add relevant supporting imagery when it strengthens the message
   • explicitly lock follow-up slides to the anchor’s headline font family / type style
   • avoid accidental serif drift or giant text-card layouts unless the anchor already uses them

8. Normalize and crop-check exports

   • save raw outputs to native/
   • normalize to a final App Store export folder like export-1320x2868/
   • visually inspect the normalized images, not just the raw renders
   • verify that no text, screenshot edge, or focal visual gets cropped out
   • if cropping is off, regenerate, normalize again, and keep checking until it works
   • use stricter center-safe rules on text-heavy slides, not just the default edge margins

9. Package review assets

   • generate a prompt-log.md
   • generate a contact-sheet.png
   • present the normalized final set for review

Included

• SKILL.md
• agents/openai.yaml
• references/
• scripts/normalize_app_store_exports.py
• scripts/build_contact_sheet.py

What It Optimizes For

• screenshots as ads, not tutorials
• consistent campaign-wide visual language
• screenshot-led compositions with relevant supporting imagery
• crop-safe layouts that survive final App Store normalization
• a native/ plus export-/ workflow
• render-safe headline formatting for image models
• follow-up slides that keep the anchor’s typography voice

Default Export Pattern

output/
  nano-banana-layout-plan.md
  prompt-log.md
  native/
  export-1320x2868/
  contact-sheet.png

Model Guidance

• Use Nano Banana Pro only by default.
• Before generation, check GEMINI_API_KEY first, then GOOGLE_API_KEY.
• If neither key is available, ask the user for the Gemini API key before generation.
• Do not switch to another image model as a fallback.

Install

skills.sh

Install it directly with skills.sh:

npx skills add chawlaaditya/NanoBananaASO

Direct clone

If you want to install it manually into a local Codex skills directory, clone it directly:

git clone https://github.com/chawlaaditya/NanoBananaASO.git "${CODEX_HOME:-$HOME/.codex}/skills/nano-banana-app-store-campaign"

Codex built-in installer

If you already have the Codex system skills available locally, you can install from GitHub with the built-in installer:

python3 "${CODEX_HOME:-$HOME/.codex}/skills/.system/skill-installer/scripts/install-skill-from-github.py" \
  --repo chawlaaditya/NanoBananaASO \
  --path .

After installing, restart Codex so the new skill is picked up.

Use

Example prompt:

Use $nano-banana-app-store-campaign to analyze this app, tell me which screenshots to capture, lock a Nano Banana Pro style anchor, and generate a consistent App Store screenshot campaign.

Examples

Here are a few real campaign contact sheets generated with the workflow:

GentleCal

RunPal