Nanobanana Skill

What it does

When your agent uses it

• The user asks to generate
• Edit an image and does NOT name another provider
• Diagrams (架构图/流程图/时序图) — draw those with Mermaid

Example prompts

• “nanobanana”
• “generate image”
• “create image”
• “/nanobanana-skill”

Requirements

• Python 3
• A credential in GEMINI_API_KEY
• Pre-approved tools (allowed-tools): Read, Write, Glob, Grep, Task, Bash(cat:*), Bash(ls:*), Bash(tree:*), Bash(python3:*)

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

1. 1GEMINI_API_KEY: Must be configured in ~/.nanobanana.env or export GEMINI_API_KEY=
2. 2Python3 with dependent packages installed: google-genai, Pillow, python-dotenv. They could be installed via python3 -m pip install -r…
3. 3Executable: ${CLAUDE_SKILL_DIR}/nanobanana.py

What it can do on your machine

Read from SKILL.md and the folder at commit 95dab59. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Write
  • Glob
  • Grep
  • Task
  • Bash(cat:*)
  • Bash(ls:*)
  • Bash(tree:*)
  • Bash(python3:*)

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Ships script files (Python), which the agent can run.

  Shell commands in SKILL.md call:

  • python3

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names these keys or tokens, usually read from environment variables:

  • GEMINI_API_KEY

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Nanobanana Skill loads about 1.1k tokens when it runs. Until then it costs about 98 tokens; SKILL.md has 343 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~98

When it runs · the whole SKILL.md, loaded when a task matches

~1.1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from feiskyer/claude-code-settings at commit 95dab59, republished under its MIT licence (© feiskyer). 343 words, ~1,101 tokens.

name

nanobanana-skill

description

Generate or edit images via Google Gemini (nanobanana). This is the DEFAULT image skill — use whenever the user asks to generate, create, or edit an image and does NOT name another provider. Triggers: "nanobanana", "generate image", "create image", "edit image", "图片生成", "生成图片", "AI绘图", "图片编辑". Do NOT use for diagrams (架构图/流程图/时序图) — draw those with Mermaid or code instead.

allowed-tools

Read, Write, Glob, Grep, Task, Bash(cat:*), Bash(ls:*), Bash(tree:*), Bash(python3:*)

python3 ${CLAUDE_SKILL_DIR}/nanobanana.py --prompt "A serene mountain landscape at sunset with a lake"

python3 ${CLAUDE_SKILL_DIR}/nanobanana.py \
  --prompt "Modern minimalist logo for a tech startup" \
  --size 1024x1024 \
  --output "logo.png"

python3 ${CLAUDE_SKILL_DIR}/nanobanana.py \
  --prompt "Futuristic cityscape with flying cars" \
  --size 1344x768 \
  --resolution 2K \
  --output "cityscape.png"

python3 ${CLAUDE_SKILL_DIR}/nanobanana.py \
  --prompt "Add a rainbow in the sky" \
  --input photo.png \
  --output "photo-with-rainbow.png"

python3 ${CLAUDE_SKILL_DIR}/nanobanana.py \
  --prompt "Detailed portrait of a cat in watercolor style" \
  --model gemini-3-pro-image-preview \
  --output "cat-portrait.png"

© feiskyer, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 2 other files in skills/nanobanana-skill of feiskyer/claude-code-settings.

• SKILL.md
• nanobanana.py
• requirements.txt

Open the folder on GitHubat commit 95dab59