cf-image-gen MCP Server

Generate images and video from text prompts using Cloudflare Workers AI (Stable Diffusion) or Google Gemini models via Cloudflare AI Gateway.

Architecture

Text Prompt → cf-image-gen MCP Server → Cloudflare AI Gateway
                                           ├── Workers AI (Stable Diffusion XL)
                                           ├── Gemini Image Models (generateContent)
                                           └── Gemini Text Models (Interactions API)

Models

Workers AI (Direct)

Model	ID	Output
Stable Diffusion XL	@cf/stabilityai/stable-diffusion-xl-base-1.0	1024×1024 PNG

Google Gemini (via AI Gateway)

Use google-ai-studio/{modelName} format.

Image Models (generateContent)

Model	Format	Notes
gemini-3.1-flash-image	image/jpeg	No text, 1120 image tokens
gemini-3-pro-image	image/jpeg	+157 reasoning tokens
gemini-2.5-flash-image	image/png	Returns text + image

Text Models (Interactions API)

Model	Notes
gemini-3.5-flash	Latest text model

Prerequisites

• Node.js 18+
• Cloudflare account with:
  • Account ID
  • API Token (Workers AI)
  • AI Gateway ID
  • AI Gateway Auth Token (for Gemini models)
• Google AI Studio API key (for Gemini models)

Environment Variables

Variable	Required	Description
CLOUDFLARE_ACCOUNT_ID	✅	Cloudflare Account ID
CLOUDFLARE_API_TOKEN	✅	Cloudflare API Token
CLOUDFLARE_GATEWAY_ID	For Gemini	AI Gateway ID
GOOGLE_AI_STUDIO_API_KEY	For Gemini	Google AI Studio API Key
CF_AIG_TOKEN	For Gemini	AI Gateway Auth Token
CF_IMAGE_OUTPUT_DIR	❌	Output directory (default: .opencode/mcp/cf-image-gen/output)

Usage

Via MCP Tool

{
  "prompt": "a samurai warrior standing on a mountain at sunset, pixel art style, 8-bit game aesthetic",
  "model": "google-ai-studio/gemini-3.1-flash-image"
}

Or with Stable Diffusion (default):

{
  "prompt": "a red apple on white background"
}

Example Output

Gemini 3.1 Flash Image — google-ai-studio/gemini-3.1-flash-image

Prompt: "a samurai warrior standing on a mountain at sunset, pixel art style, 8-bit game aesthetic"

How It Works

1. Workers AI path: Direct call to POST /accounts/{id}/ai/run/{model} with Cloudflare API Token
2. AI Gateway path: Routes through gateway.ai.cloudflare.com/v1/{account}/{gateway}/
   • Image-capable models → v1beta/models/{model}:generateContent with generationConfig.responseModalities: ["IMAGE"]
   • Text-only models (gemini-3-flash*) → v1beta/interactions with plain string input

Development

# Install dependencies
cd .opencode/mcp/cf-image-gen
npm install

# Run standalone (stdio)

# Configure in opencode.jsonc as MCP server

License

MIT