Retro Diffusion MCP Server

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This is a hosted, remote MCP server — nothing to install or run locally. Point your client at the endpoint, add your API key, and your assistant can browse 90+ pixel art styles, estimate costs for free, generate game-ready art, and repair enlarged or softened pixel art.

Endpoint:  https://mcp.retrodiffusion.ai/mcp     (Streamable HTTP)
Auth:      Authorization: Bearer <your API key>   (keys start with rdpk-)

The hosted MCP endpoint remains backward compatible and defaults to Retro Diffusion API v2. Its server-side version policy is described in API compatibility; MCP clients do not change their endpoint or authentication settings.

Get an API key (2 minutes)

1. Create a free account at retrodiffusion.ai — new accounts include free starter credits.
2. Open Developer Tools and click Create API Key.

Pricing is pay-per-generation (from ~$0.01 per image), prepaid, no subscription, and credits never expire. Cost estimation is always free, so your agent can check the price of anything before spending.

Setup by client

Claude Code

claude mcp add --transport http retro-diffusion https://mcp.retrodiffusion.ai/mcp \
  --header "Authorization: Bearer rdpk-YOUR-KEY"

Or install the plugin (bundles the server plus a pixel-art workflow skill):

/plugin marketplace add Retro-Diffusion/retro-diffusion-mcp
/plugin install pixel-art@retro-diffusion

Cursor

Click the Add to Cursor badge above, then replace YOUR_API_KEY — or add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "retro-diffusion": {
      "url": "https://mcp.retrodiffusion.ai/mcp",
      "headers": { "Authorization": "Bearer rdpk-YOUR-KEY" }
    }
  }
}

VS Code (GitHub Copilot)

Add to mcp.json (Command Palette → "MCP: Add Server" → HTTP):

{
  "servers": {
    "retro-diffusion": {
      "type": "http",
      "url": "https://mcp.retrodiffusion.ai/mcp",
      "headers": { "Authorization": "Bearer rdpk-YOUR-KEY" }
    }
  }
}

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "retro-diffusion": {
      "serverUrl": "https://mcp.retrodiffusion.ai/mcp",
      "headers": { "Authorization": "Bearer rdpk-YOUR-KEY" }
    }
  }
}

Claude Desktop

Use mcp-remote in claude_desktop_config.json:

{
  "mcpServers": {
    "retro-diffusion": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://mcp.retrodiffusion.ai/mcp",
        "--header",
        "Authorization: Bearer rdpk-YOUR-KEY"
      ]
    }
  }
}

Anything else

Any MCP client that speaks Streamable HTTP works: URL https://mcp.retrodiffusion.ai/mcp, header Authorization: Bearer rdpk-YOUR-KEY.

Tools

Generate

Tool	What it does
create_inference	Generate images, animations (GIF/sprite sheet), or tilesets. Returns hosted URLs and a recovery request_id; prefer RD Pro styles for top quality
get_inference_result	Recover or refresh signed output URLs for a successful synchronous generation without generating or charging again
start_inference_job	Start generation as an async job — recommended for animations and batches
get_inference_job	Poll an async job for status and results
list_inference_jobs	List your recent async jobs — recover a task_id after a lost submission response instead of re-submitting and double-charging
estimate_inference_cost	Free price check for any generation before running it

Generation is non-idempotent and may charge before a client timeout or delivery problem is visible. If create_inference succeeds but its output_urls are missing or expired, call get_inference_result(request_id). Never repeat the generation automatically. The MCP omits raw generation base64 to keep Cursor and other tool contexts compact, and uses short-lived hosted URLs for delivery instead.

Edit — post-process any image

Tool	What it does
list_edit_tools	Enabled edit tools with their fields, costs, and limits
run_edit_tool	Run an edit tool: background remover, palette converter, color reducer, pixel correction, rotation, K-centroid downscale (free–$0.01) · image edit, inpainting, outpainting, seam tiling (premium)
estimate_edit_tool_cost	Free cost/duration estimate for any edit
fix_pixel_art	Free recovery of the native pixel grid from enlarged, softened, AI-rendered, or compressed pixel art

Styles

Tool	What it does
list_available_styles	Live style catalog with per-style size limits and capabilities
list_available_models	The model families: RD Fast, RD Plus, RD Pro, RD Mini
get_style_usage	Usage guidance and constraints for a specific style
create_user_style	Create a custom style from a reference image (RD Pro template)
update_user_style	Modify one of your custom styles
delete_user_style	Remove one of your custom styles

Account

Tool	What it does
authenticate	Validate an API key and attach it to the session
get_balance	Check remaining prepaid balance and credits
get_service_status	Subsystem health check (no auth required)
logout	Clear the stored session key

fix_pixel_art accepts PNG or JPEG as raw base64 or a data URL. Images must be at least 16×16 and no more than 4 megapixels. Standard and neural share a 10 requests/minute limit per API key; request JSON is capped at 900,000 bytes and successful response JSON at 850,000 bytes. Use the standard engine for native Rust grid detection or the neural engine with optional target width and height values.

What you can make

• Sprites & characters — 90+ styles: portraits, game assets, isometric, top-down, platformer, 1-bit, Minecraft items/textures, UI elements, item sheets, character turnarounds
• Animations — walk/idle/jump/crouch/attack cycles from a start frame, four-angle walk cycles, 8-direction rotations, VFX, battle sprites; GIF or sprite-sheet output
• Tilesets — Wang/blob tilesets, tile variations, single tiles, scene objects
• Consistent characters — generate once with RD Pro, then pass the output as a reference image in follow-up generations (up to 9 references)
• Edits — img2img, seamless tiling, transparent backgrounds, palette-constrained output
• Pixel repair — reconstruct enlarged or softened pixel art at its detected native resolution

Example prompts to try once connected:

"List the available pixel art styles for animations, then estimate what a 64×64 walking animation would cost."

"Generate a 128×128 pixel art knight resting by a campfire, RD Pro default style, transparent background."

"Create a 16×16 Wang tileset: grey stone path tiles blending into lush grass."

"Fix this enlarged sprite back to its native pixel grid using the standard Pixel Fixer."

Prompting tips (important)

• Describe the subject only — never write "pixel art" in the prompt; the style handles the rendering.
• Sizes run 16×16 to 384×384 depending on style; list_available_styles gives exact per-style limits.
• Costs range from ~$0.015 (RD Fast) to $0.18/image (RD Pro); animations $0.07–$0.25; tilesets $0.10. estimate_inference_cost is always free — use it first.
• Reuse a seed to iterate on the same composition while changing only the prompt.

Who makes this

Retro Diffusion is built by Astropulse — a pixel artist with seven years of freelance experience before building the tool — and is used in production by studios and platforms including Replicate, Poe (Quora), and Scenario. It's designed by artists and held to artist-grade quality standards.

Support

• Discord community — fastest answers, the founder is active daily
• Full API reference and runnable examples
• API v1/v2 compatibility — v2 default, v1 support, error contract, request IDs, and retry rules
• Service status (no auth required)

License

The contents of this repository (documentation and manifests) are MIT licensed. The Retro Diffusion service itself is governed by its Terms of Service.