Poster Designer Skill

Create professional posters and visual designs using AI image generation.

Quick Start

Generate a poster:

poster create --type event --title "Summer Music Festival" --date "2026-07-15"

Capabilities

Event Posters — Concerts, conferences, meetups, parties
Product Showcases — E-commerce listings, feature highlights
Announcements — Launches, openings, special offers
Social Media — Instagram, Facebook, Twitter graphics

Usage Patterns

Interactive Mode

Simply describe what you want:

"Create a poster for my band's gig next Friday at the Blue Note"

The skill will ask clarifying questions and generate the poster.

Template Mode

Use predefined templates:

event — General event poster with date/time/location
concert — Music-focused with band name and setlist
product — Product showcase with features and pricing
announcement — News/launch announcement
sale — Promotional sale poster

Custom Mode

Provide detailed specifications:

"Create a minimalist poster, 1080x1920 (9:16), dark blue background, neon pink text, featuring a geometric guitar illustration"

Configuration

Set your Gemini API key:

export GEMINI_API_KEY="your-api-key"

Or create .env in the skill directory by copying .env.example:

cp .env.example .env
# Edit .env and add your API key

Security Note: Never commit your .env file or share your API key. Keep it in environment variables or secure secret storage.

Get your API key from: https://makersuite.google.com/app/apikey

Output Formats

PNG — Default high-quality raster output
With Text Overlay — Generated image with text composited
Raw + Composite — Both the base image and final poster

Design Principles

Typography

Keep text readable (minimum 24pt for important info)
Use 2-3 fonts maximum
Ensure high contrast between text and background

Composition

Follow the rule of thirds
Leave breathing room (don't overcrowd)
Use visual hierarchy (most important info largest)

Color

Use complementary or analogous color schemes
Ensure accessibility (WCAG AA contrast minimum)
Consider brand colors when provided

API Integration

The skill uses Gemini image generation API with native multimodal capabilities:

Model: gemini-3.1-flash-image-preview (configurable)
Supports aspect ratios: 1:1, 4:3, 16:9, 9:16, 3:4
Output sizes: 1K (~1024px), 2K (~2048px), 4K (~3840px)

See references/api-docs.md for detailed API documentation.

Templates

See references/templates.md for available templates and customization options.

Examples

Event Poster

User: "Create a poster for a tech conference on May 15th"

Skill asks:
- Event name?
- Venue?
- Speaker lineup (optional)?
- Style preference (modern/minimal/bold)?

Then generates poster with:
- Compelling headline
- Date/time/venue prominently displayed
- Speaker photos or tech-themed visuals
- QR code placeholder for tickets

Product Showcase

User: "Design a product poster for my new wireless headphones"

Skill asks:
- Product name?
- Key features?
- Price?
- Style/tone?

Then generates:
- Hero product image
- Feature callouts
- Price and CTA
- Brand-appropriate styling

Error Handling

If image generation fails:

Retry with exponential backoff (up to 3 attempts)
Provide detailed error message
Offer to adjust prompt and retry

Security & Safety

All generated content follows Gemini safety guidelines
User content is not stored persistently
API keys are never logged or exposed
.env.example is provided as a template - copy to .env and add your key
Never commit .env files with real credentials
Keep API keys in environment variables or secure secret storage