MCP Flux Studio

Instructions

Implementation Reference

• src/index.ts:292-313 (handler)

  MCP tool handler for 'generate': validates args, builds CLI command, executes Python fluxcli.py generate, returns output.
  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 }], }; }
• src/index.ts:131-168 (registration)

  Registration of the 'generate' tool in ListTools response, including name, description, and input schema.
  { 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'], }, },
• src/types.ts:37-44 (schema)

  TypeScript interface defining the input arguments for the 'generate' tool.
  export interface GenerateArgs { prompt: string; model?: FluxModel; aspect_ratio?: AspectRatio; width?: number; height?: number; output?: string; }
• src/index.ts:45-85 (helper)

  Helper method to execute the Python CLI script (fluxcli.py) with given arguments, capturing output or error.
  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}`)); } }); }); }
• src/cli/fluxcli.py:76-126 (helper)

  Core image generation logic in Python CLI: constructs payload for FLUX API endpoint based on model, submits request, polls for result URL.
  def generate_image(self, prompt: str, model: str = "flux.1.1-pro", width: int = None, height: int = None, aspect_ratio: str = None) -> Optional[str]: """Generate an image using any FLUX model.""" endpoint = { "flux.1.1-pro": "/v1/flux-pro-1.1", "flux.1-pro": "/v1/flux-pro", "flux.1-dev": "/v1/flux-dev", "flux.1.1-ultra": "/v1/flux-pro-1.1-ultra", }.get(model) if not endpoint: raise ValueError(f"Unknown model: {model}") # Set default dimensions based on aspect ratio if provided if aspect_ratio: if aspect_ratio == '1:1': width, height = 1024, 1024 elif aspect_ratio == '4:3': width, height = 1024, 768 elif aspect_ratio == '3:4': width, height = 768, 1024 elif aspect_ratio == '16:9': width, height = 1024, 576 elif aspect_ratio == '9:16': width, height = 576, 1024 else: # Use defaults if neither aspect ratio nor dimensions are provided width = width or 1024 height = height or 768 payload = { "prompt": prompt, "width": width, "height": height, "aspect_ratio": aspect_ratio if aspect_ratio else None } response = requests.post( f"{self.base_url}{endpoint}", json=payload, headers=self.headers ) task_id = response.json().get('id') if not task_id: print("Failed to start generation task") return None result = self.get_task_result(task_id) if result and result.get('result', {}).get('sample'): return result['result']['sample'] return None