MCP Flux Studio

#!/usr/bin/env node import { Server } from '@modelcontextprotocol/sdk/server/index.js'; import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js'; import { CallToolRequestSchema, ErrorCode, ListToolsRequestSchema, McpError, } from '@modelcontextprotocol/sdk/types.js'; import { spawn } from 'child_process'; import type { GenerateArgs, Img2ImgArgs, InpaintArgs, ControlArgs, FluxServerConfig, ToolResponse } from './types.js'; class FluxServer { private server: Server; private fluxPath: string; constructor(config?: FluxServerConfig) { this.server = new Server({ name: 'flux-server', version: '0.1.0', }, { capabilities: { tools: {}, }, }); // Path to Flux installation this.fluxPath = config?.fluxPath || process.env.FLUX_PATH || '/Users/speed/CascadeProjects/flux'; // Validate configuration if (!process.env.BFL_API_KEY) { console.error('[Warning] BFL_API_KEY environment variable not set'); } this.setupToolHandlers(); // Error handling this.server.onerror = (error) => console.error('[MCP Error]', error); process.on('SIGINT', async () => { await this.server.close(); process.exit(0); }); } private async runPythonCommand(args: string[]): Promise<string> { return new Promise((resolve, reject) => { // Validate arguments if (!args || args.length === 0) { reject(new Error('No command arguments provided')); return; } // Use python from virtual environment if available const pythonPath = process.env.VIRTUAL_ENV ? `${process.env.VIRTUAL_ENV}/bin/python` : 'python3'; const childProcess = spawn(pythonPath, ['fluxcli.py', ...args], { cwd: this.fluxPath, env: process.env, // Pass through all environment variables }); let output = ''; let errorOutput = ''; childProcess.stdout?.on('data', (data) => { output += data.toString(); }); childProcess.stderr?.on('data', (data) => { errorOutput += data.toString(); }); childProcess.on('error', (error) => { reject(new Error(`Failed to spawn Python process: ${error.message}`)); }); childProcess.on('close', (code) => { if (code === 0) { resolve(output); } else { reject(new Error(`Flux command failed (exit code ${code}): ${errorOutput}`)); } }); }); } /** * Validates that a required string parameter is provided */ private validateRequiredString(value: unknown, fieldName: string): string { if (typeof value !== 'string' || value.trim() === '') { throw new McpError( ErrorCode.InvalidParams, `${fieldName} is required and must be a non-empty string` ); } return value; } /** * Validates numeric parameters within acceptable ranges */ private validateNumber(value: unknown, fieldName: string, min?: number, max?: number): number | undefined { if (value === undefined || value === null) { return undefined; } if (typeof value !== 'number' || isNaN(value)) { throw new McpError( ErrorCode.InvalidParams, `${fieldName} must be a valid number` ); } if (min !== undefined && value < min) { throw new McpError( ErrorCode.InvalidParams, `${fieldName} must be at least ${min}` ); } if (max !== undefined && value > max) { throw new McpError( ErrorCode.InvalidParams, `${fieldName} must be at most ${max}` ); } return value; } setupToolHandlers() { this.server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: [ { name: 'generate', description: 'Generate an image from a text prompt', inputSchema: { type: 'object', properties: { prompt: { type: 'string', description: 'Text prompt for image generation', }, model: { type: 'string', description: 'Model to use for generation', enum: ['flux.1.1-pro', 'flux.1-pro', 'flux.1-dev', 'flux.1.1-ultra'], default: 'flux.1.1-pro', }, aspect_ratio: { type: 'string', description: 'Aspect ratio of the output image', enum: ['1:1', '4:3', '3:4', '16:9', '9:16'], }, width: { type: 'number', description: 'Image width (ignored if aspect-ratio is set)', }, height: { type: 'number', description: 'Image height (ignored if aspect-ratio is set)', }, output: { type: 'string', description: 'Output filename', default: 'generated.jpg', }, }, required: ['prompt'], }, }, { name: 'img2img', description: 'Generate an image using another image as reference', inputSchema: { type: 'object', properties: { image: { type: 'string', description: 'Input image path', }, prompt: { type: 'string', description: 'Text prompt for generation', }, model: { type: 'string', description: 'Model to use for generation', enum: ['flux.1.1-pro', 'flux.1-pro', 'flux.1-dev', 'flux.1.1-ultra'], default: 'flux.1.1-pro', }, strength: { type: 'number', description: 'Generation strength', default: 0.85, }, width: { type: 'number', description: 'Output image width', }, height: { type: 'number', description: 'Output image height', }, output: { type: 'string', description: 'Output filename', default: 'outputs/generated.jpg', }, name: { type: 'string', description: 'Name for the generation', }, }, required: ['image', 'prompt', 'name'], }, }, { name: 'inpaint', description: 'Inpaint an image using a mask', inputSchema: { type: 'object', properties: { image: { type: 'string', description: 'Input image path', }, prompt: { type: 'string', description: 'Text prompt for inpainting', }, mask_shape: { type: 'string', description: 'Shape of the mask', enum: ['circle', 'rectangle'], default: 'circle', }, position: { type: 'string', description: 'Position of the mask', enum: ['center', 'ground'], default: 'center', }, output: { type: 'string', description: 'Output filename', default: 'inpainted.jpg', }, }, required: ['image', 'prompt'], }, }, { name: 'control', description: 'Generate an image using structural control', inputSchema: { type: 'object', properties: { type: { type: 'string', description: 'Type of control to use', enum: ['canny', 'depth', 'pose'], }, image: { type: 'string', description: 'Input control image path', }, prompt: { type: 'string', description: 'Text prompt for generation', }, steps: { type: 'number', description: 'Number of inference steps', default: 50, }, guidance: { type: 'number', description: 'Guidance scale', }, output: { type: 'string', description: 'Output filename', }, }, required: ['type', 'image', 'prompt'], }, }, ], })); this.server.setRequestHandler(CallToolRequestSchema, async (request): Promise<ToolResponse> => { try { switch (request.params.name) { case 'generate': { const args = request.params.arguments as GenerateArgs; // Validate required fields const prompt = this.validateRequiredString(args.prompt, 'prompt'); // Validate optional numeric fields const width = this.validateNumber(args.width, 'width', 256, 2048); const height = this.validateNumber(args.height, 'height', 256, 2048); const cmdArgs = ['generate']; cmdArgs.push('--prompt', prompt); if (args.model) cmdArgs.push('--model', args.model); if (args.aspect_ratio) cmdArgs.push('--aspect-ratio', args.aspect_ratio); if (width) cmdArgs.push('--width', width.toString()); if (height) cmdArgs.push('--height', height.toString()); if (args.output) cmdArgs.push('--output', args.output); const output = await this.runPythonCommand(cmdArgs); return { content: [{ type: 'text', text: output }], }; } case 'img2img': { const args = request.params.arguments as Img2ImgArgs; // Validate required fields const image = this.validateRequiredString(args.image, 'image'); const prompt = this.validateRequiredString(args.prompt, 'prompt'); const name = this.validateRequiredString(args.name, 'name'); // Validate optional numeric fields const strength = this.validateNumber(args.strength, 'strength', 0, 1); const width = this.validateNumber(args.width, 'width', 256, 2048); const height = this.validateNumber(args.height, 'height', 256, 2048); const cmdArgs = ['img2img']; cmdArgs.push('--image', image); cmdArgs.push('--prompt', prompt); cmdArgs.push('--name', name); if (args.model) cmdArgs.push('--model', args.model); if (strength !== undefined) cmdArgs.push('--strength', strength.toString()); if (width) cmdArgs.push('--width', width.toString()); if (height) cmdArgs.push('--height', height.toString()); if (args.output) cmdArgs.push('--output', args.output); const output = await this.runPythonCommand(cmdArgs); return { content: [{ type: 'text', text: output }], }; } case 'inpaint': { const args = request.params.arguments as InpaintArgs; // Validate required fields const image = this.validateRequiredString(args.image, 'image'); const prompt = this.validateRequiredString(args.prompt, 'prompt'); const cmdArgs = ['inpaint']; cmdArgs.push('--image', image); cmdArgs.push('--prompt', prompt); if (args.mask_shape) cmdArgs.push('--mask-shape', args.mask_shape); if (args.position) cmdArgs.push('--position', args.position); if (args.output) cmdArgs.push('--output', args.output); const output = await this.runPythonCommand(cmdArgs); return { content: [{ type: 'text', text: output }], }; } case 'control': { const args = request.params.arguments as ControlArgs; // Validate required fields const type = this.validateRequiredString(args.type, 'type') as ControlType; const image = this.validateRequiredString(args.image, 'image'); const prompt = this.validateRequiredString(args.prompt, 'prompt'); // Validate optional numeric fields const steps = this.validateNumber(args.steps, 'steps', 1, 100); const guidance = this.validateNumber(args.guidance, 'guidance', 0, 100); const cmdArgs = ['control']; cmdArgs.push('--type', type); cmdArgs.push('--image', image); cmdArgs.push('--prompt', prompt); if (steps) cmdArgs.push('--steps', steps.toString()); if (guidance !== undefined) cmdArgs.push('--guidance', guidance.toString()); if (args.output) cmdArgs.push('--output', args.output); const output = await this.runPythonCommand(cmdArgs); return { content: [{ type: 'text', text: output }], }; } default: throw new McpError(ErrorCode.MethodNotFound, `Unknown tool: ${request.params.name}`); } } catch (error) { // Handle McpError differently - rethrow to let SDK handle it if (error instanceof McpError) { throw error; } // Log detailed error for debugging console.error('[Tool Execution Error]', error); return { content: [ { type: 'text', text: `Error: ${error instanceof Error ? error.message : String(error)}`, }, ], isError: true, }; } }); } async run() { const transport = new StdioServerTransport(); await this.server.connect(transport); console.error('Flux MCP server running on stdio'); } } const server = new FluxServer(); server.run().catch(console.error);