Blog Cover Generator

Blog Cover Generator Skill

This skill provides AI agents with the ability to generate stunning, minimalist, technical blog cover images using the blog-cover-image-cli. The CLI leverages Gemini 3.1 Flash Image Preview, automatically fetches brand logos from domains, uses local aesthetic reference images, and employs Google Search grounding to inject real-time context.

Setup & Configuration

Agent Pre-requisites: Before using this tool, verify it is installed. If blog-cover-cli --help fails, install it globally:

npm install -g blog-cover-image-cli

If the user wants you to generate an image and you haven't set up the API key yet, you must first configure the CLI using a Gemini API Key. The CLI stores this securely via the conf package.

# 1. Set your Gemini API Key (Required for image generation)
npx -p blog-cover-image-cli blog-cover-cli config set-key 

# 2. Set your Brandfetch Client ID (Required to fetch high-res logos)
npx -p blog-cover-image-cli blog-cover-cli config set-brandfetch-id 

# Check your keys (masked)
npx -p blog-cover-image-cli blog-cover-cli config get-key
npx -p blog-cover-image-cli blog-cover-cli config get-brandfetch-id

Usage: Generating an Image

When a user asks for a cover image (e.g., "Create a cover image for my blog about Vercel v0"), you should use the generate command.

npx -p blog-cover-image-cli blog-cover-cli generate -t "The Title of the Blog Post" -l "example.com"

Arguments

• -t, --title : (Required) The title text to display on the cover image. Do not use excessively long titles (keep it under 3 lines of text visually).
• -l, --logo : (Optional but recommended) The domain to fetch the brand logo from (e.g., vercel.com, google.com, cursor.com). The CLI automatically converts WebP/SVG/AVIF to PNG for compatibility.
• -o, --output : (Optional) The file path where the generated image will be saved. If omitted, the CLI automatically saves it to an output/ directory in the current working folder (e.g., ./output/vercel-cover.png).

Examples

Example 1: Cursor

npx -p blog-cover-image-cli blog-cover-cli generate -t "Why Cursor is the Ultimate AI Code Editor" -l "cursor.com"

Example 2: Lovable

npx -p blog-cover-image-cli blog-cover-cli generate -t "Building Apps in Minutes with Lovable" -l "lovable.dev"

Example 3: Custom Output Path

npx -p blog-cover-image-cli blog-cover-cli generate -t "Mastering React in 2026" -l "reactjs.org" -o "./assets/react-cover.png"

How It Works Under the Hood

As an agent, you should know what the CLI is doing so you can inform the user:

1. Logo Fetching: It fetches logos from Brandfetch and processes them via sharp.
2. References: It loads curated reference images from its examples/ directory to ensure the output is always a clean, minimalist white background with bold typography.
3. Grounding: It has googleSearch tools enabled, meaning if the title relates to a recent event, Gemini can look it up before generating the image.
4. Text Enforcement: It forces Gemini to output the exact title string using typographic placement rules.

Edge Cases / Troubleshooting

• No API Key Error: If you see an API key error, run the config set-key command.
• Logo Fetch Warning: If the CLI says Warning: Could not fetch logo, it will still generate the image but without the logo. You do not need to crash or stop.
• Strict Modality Limits: Because it uses Gemini's experimental image models, generation may occasionally fail due to strict safety filters. If this happens, notify the user.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Varnan-Tech
• Source: Varnan-Tech/opendirectory
• License: MIT
• Homepage: https://www.opendirectory.dev

Install and usage instructions live in the source repository linked above.