Pixara MCP Server

An MCP server that gives LLMs direct access to OpenRouter's Image API to generate images, edit/transform existing ones, and browse the model catalog, all through 4 tools.

I built this because I saw that OpenRouter announced a unified Image API that gives you one endpoint to use image generation and image editing models like GPT Image, Nano Banana, Flux, etc. Use the pixara_list_image_models tool to see the full, current models list from OpenRouter.

Features

• Generate images from a text prompt against any OpenRouter image model
• Edit/transform images (img2img) using a local file, a URL, or raw base64 as the reference, and the tool reads and encodes local files for you
• List models with filtering by provider, name, and capability (img2img, streaming, transparent background), plus pagination
• Inspect a model's endpoint details: per-provider pricing, supported parameters, and allowed passthrough options — before you spend a call on something it doesn't support
• Generated images are decoded and saved to disk, so responses stay small and a file path is returned
• Clear error messages for common failure modes: bad/conflicting params, invalid key, insufficient credits, rate limits, provider unavailable

Quick start (recommended)

Pixara is published on npm as @pinkpixel/pixara-mcp. The easiest way to use it is via npx — no install, no cloning, no build step.

Add this to your MCP config (claude_desktop_config.json) for Claude Desktop, or your MCP client's .json config file:

{
  "mcpServers": {
    "pixara": {
      "command": "npx",
      "args": ["-y", "@pinkpixel/pixara-mcp"],
      "env": {
        "OPENROUTER_API_KEY": "sk-or-v1-your-key-here",
        "OPENROUTER_IMAGE_OUTPUT_DIR": "/absolute/path/to/wherever/you/want/images"
      }
    }
  }
}

Restart the client and you should see the four pixara_* tools available. npx -y fetches and caches the package on first run, so there's nothing to update manually. New versions get picked up automatically.

Configuration

Variable	Required	Description
OPENROUTER_API_KEY	Yes	Get one at openrouter.ai/keys
OPENROUTER_IMAGE_OUTPUT_DIR	No	Where generated images are saved. Defaults to ./pixara-images

The server just reads these from process.env — there's no .env file loading built in. Whether you're running via npx or from source, set these in the env block of your MCP config, as shown above. OPENROUTER_IMAGE_OUTPUT_DIR is optional — leave it out and images save to ./pixara-images relative to wherever the server process runs; set it to an absolute path if you want a predictable location regardless of the client's working directory.

Installing from source

For local development, or if you'd rather not rely on npx:

Requires Node.js 18+.

git clone https://github.com/sizzlebop/pixara-mcp.git
cd pixara-mcp
npm install
npm run build

Then point your MCP config at the built file instead of npx:

{
  "mcpServers": {
    "pixara": {
      "command": "node",
      "args": ["/absolute/path/to/openrouter-image-mcp/dist/index.js"],
      "env": {
        "OPENROUTER_API_KEY": "sk-or-v1-your-key-here",
        "OPENROUTER_IMAGE_OUTPUT_DIR": "/absolute/path/to/wherever/you/want/images"
      }
    }
  }
}

Tools

pixara_generate_image

Text-to-image. Required: model, prompt. Optional: n, resolution, aspect_ratio, size, quality, output_format, background, output_compression, seed, provider_options, output_dir, filename_prefix.

Don't combine size with resolution/aspect_ratio — pick one or the other, the tool will reject the call with a clear message if you mix them.

pixara_edit_image

Same params as generate_image, plus a required input_references array. Each entry is one of:

{ "source": "file", "path": "/path/to/photo.png" }
{ "source": "url", "url": "https://example.com/photo.jpg" }
{ "source": "base64", "data": "<base64>", "media_type": "image/png" }

pixara_list_image_models

Read-only, free (no image billing). Filter by filter (substring), provider, or capability booleans (supports_img2img, supports_streaming, supports_transparent_background). Paginated with limit/offset.

pixara_get_model_details

Read-only, free. Pass a model slug, get back per-provider pricing and exactly which parameters/passthrough options that provider supports. Worth calling before you use provider_options, since unsupported params get silently dropped or rejected by the API.

How it decides where to save images

Every generate/edit call decodes the base64 image(s) OpenRouter returns and writes them to OPENROUTER_IMAGE_OUTPUT_DIR (or a per-call output_dir override), named {prefix}-{timestamp}-{index}.{ext}. The extension follows output_format, except for vector output (Recraft's SVG models), which is detected via the response's media_type and written as .svg regardless of what output_format was requested.

Limitations

• No SSE streaming support yet (see Roadmap)
• Model capabilities vary a lot by provider, and OpenRouter's catalog moves fast — always trust pixara_list_image_models/pixara_get_model_details over any hardcoded list
• This is new — OpenRouter's Image API has only been out a couple of weeks, so expect model IDs and params to shift over time

License

Apache 2.0 — see LICENSE.

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Made with 💖 by Pink Pixel