index.js•5.51 kB
#!/usr/bin/env node
/**
* Grok Image Generator MCP Server
* Implements AI image generation capabilities using the xAI/Grok API.
* Provides tools for generating images based on text prompts.
*/
import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { CallToolRequestSchema, ListToolsRequestSchema, ErrorCode, McpError, } from "@modelcontextprotocol/sdk/types.js";
import axios from "axios";
/**
* Retrieve the xAI API key from environment variables.
* This must be provided in the MCP server configuration.
*/
const XAI_API_KEY = process.env.XAI_API_KEY;
if (!XAI_API_KEY) {
throw new Error("XAI_API_KEY environment variable is required");
}
/**
* Create an MCP server with capabilities for AI image generation tools.
*/
const server = new Server({
name: "grokart",
version: "0.1.0",
}, {
capabilities: {
tools: {},
},
});
/**
* Axios instance for making API calls to xAI API.
*/
const xaiApi = axios.create({
baseURL: "https://api.x.ai/v1",
headers: {
"Content-Type": "application/json",
"Authorization": `Bearer ${XAI_API_KEY}`,
},
});
/**
* Handler that lists available tools.
* Exposes image generation tool that let clients generate images.
*/
server.setRequestHandler(ListToolsRequestSchema, async () => {
return {
tools: [
{
name: "generate_image",
description: "Generate images using Grok-2-image model based on a text prompt",
inputSchema: {
type: "object",
properties: {
prompt: {
type: "string",
description: "Text description of the image you want to generate"
},
n: {
type: "number",
description: "Number of images to generate (1-10, default: 1)",
minimum: 1,
maximum: 10,
default: 1
},
response_format: {
type: "string",
description: "Format of the generated images ('url' or 'b64_json')",
enum: ["url", "b64_json"],
default: "url"
}
},
required: ["prompt"]
}
}
]
};
});
/**
* Handler for the generate_image tool.
* Calls the xAI API to generate images based on the provided prompt.
*/
server.setRequestHandler(CallToolRequestSchema, async (request) => {
if (request.params.name !== "generate_image") {
throw new McpError(ErrorCode.MethodNotFound, `Unknown tool: ${request.params.name}`);
}
// Extract and validate parameters
const args = request.params.arguments;
const prompt = args?.prompt;
const n = args?.n || 1;
const responseFormat = args?.response_format || "url";
if (!prompt || typeof prompt !== "string") {
throw new McpError(ErrorCode.InvalidParams, "A text prompt is required");
}
if (n < 1 || n > 10 || !Number.isInteger(n)) {
throw new McpError(ErrorCode.InvalidParams, "Number of images (n) must be an integer between 1 and 10");
}
if (responseFormat !== "url" && responseFormat !== "b64_json") {
throw new McpError(ErrorCode.InvalidParams, "response_format must be either 'url' or 'b64_json'");
}
try {
// Make API call to xAI image generation endpoint
const response = await xaiApi.post("/images/generations", {
model: "grok-2-image",
prompt,
n,
response_format: responseFormat
});
// Format the response to send back to the client
const images = response.data.data;
const revisedPrompt = images[0].revised_prompt || prompt;
const result = {
generated_images: images.map((img, index) => ({
index,
image_type: responseFormat,
[responseFormat]: responseFormat === "url" ? img.url : img.b64_json
})),
revised_prompt: revisedPrompt,
original_prompt: prompt,
num_images: images.length
};
return {
content: [{
type: "text",
text: JSON.stringify(result, null, 2)
}]
};
}
catch (error) {
console.error("Error calling xAI API:", error);
if (axios.isAxiosError(error)) {
const statusCode = error.response?.status || 500;
const errorMessage = error.response?.data?.error?.message || error.message;
throw new McpError(ErrorCode.InternalError, `xAI API Error (${statusCode}): ${errorMessage}`);
}
throw new McpError(ErrorCode.InternalError, `Error generating image: ${String(error)}`);
}
});
/**
* Start the server using stdio transport.
* This allows the server to communicate via standard input/output streams.
*/
async function main() {
const transport = new StdioServerTransport();
await server.connect(transport);
console.error("Grok Image Generator MCP server running on stdio");
}
main().catch((error) => {
console.error("Server error:", error);
process.exit(1);
});