Response Illustrator MCP

中文说明

An MCP server that adds illustrative images to responses. It exposes an image generation and editing service over MCP stdio for clients such as Cherry Studio, and returns Markdown images together with locally hosted HTTP URLs so clients can render them directly.

Configure image generation

Copy config.example.json to create your configuration file, then set the API URL, model, API key environment variable, and timeout as needed.

The example uses OpenAI's Images API and the gpt-image-1 model. Other OpenAI-compatible image APIs can be used by changing the endpoint and model.

{
  "apiUrl": "https://api.openai.com/v1/images/generations",
  "editApiUrl": "https://api.openai.com/v1/images/edits",
  "model": "gpt-image-1",
  "apiKeyEnv": "OPENAI_API_KEY",
  "timeoutMs": 120000
}

The default configuration file locations are:

• Windows: %APPDATA%\\seedream-image-mcp\\config.json

• macOS / Linux: $XDG_CONFIG_HOME/seedream-image-mcp/config.json, or ~/.config/seedream-image-mcp/config.json when XDG_CONFIG_HOME is not set

Use --config PATH to select another file. Required fields are apiUrl, model, apiKeyEnv, and timeoutMs. editApiUrl is optional; when omitted, reference-image requests use apiUrl.

Related MCP server: mcp-media-engine

Configure the API key

Create a .env file in the project directory. The variable name must match apiKeyEnv:

OPENAI_API_KEY=replace-with-your-api-key

Keep .env out of version control and never put a real key in JSON configuration.

Cherry Studio configuration

Install dependencies first:

bun install

In Cherry Studio, add an MCP server and replace the example paths with the paths on your machine:

{
  "mcpServers": {
    "response-illustrator": {
      "command": "bun",
      "args": [
        "run",
        "/path/to/your/project/src/index.ts",
        "--env-file",
        "/path/to/your/project/.env",
        "--config",
        "/path/to/your/project/config.local.json"
      ]
    }
  }
}

Cherry Studio and the MCP server must run on the same computer so the client can access returned http://127.0.0.1:<port>/images/... URLs. Generated images are stored in a temporary directory and cleaned up automatically after 24 hours.

Recommended system prompt

Add the following system prompt in Cherry Studio to let the assistant decide when an answer benefits from an illustration:

You are a helpful assistant. Answer the user in {{language}}.

For every response, decide whether an illustration would make the explanation clearer.
- Use the MCP generate-image tool when an image can explain a complex concept, show a relationship, or illustrate a process.
- Do not use the tool for simple facts, calculations, code, definitions, or content that is already clear without an image.
- When an image is useful, call the tool while generating the answer and place the returned Markdown image near the relevant explanation. Do not replace the image URL with another URL.

Tool reference

The MCP tool is named generate-image and accepts:

• prompt: image description, up to 5000 characters

• size: optional image size, default auto

• images: optional array of reference-image URLs, up to 16 images

The server accepts image URLs and base64 image data. Generated images are cached locally and returned as Markdown image URLs. Each image is limited to 20 MB.

Local development

bun install
bun test
bun run build

To select environment and configuration files explicitly:

bun run src/index.ts --env-file .env --config config.local.json

Troubleshooting

• Confirm that the environment variable in .env matches apiKeyEnv.

• If Cherry Studio cannot display an image, check that both processes run on the same computer and that the client can reach the local URL.

• Verify the API URL, model name, and timeout against the provider's documentation.