import { z } from 'zod';
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { getBlenderClient } from '../utils/socket-client.js';
import { screenshotSizeSchema } from '../utils/validators.js';
import type { ToolResult, ToolContent } from '../types/index.js';
const GetScreenshotSchema = z.object({
max_size: screenshotSizeSchema.default(800).describe('Max dimension in pixels (100-800)')
}).strict();
// Type guard to validate screenshot response data
interface ScreenshotResult {
image_data: string;
width?: number;
height?: number;
format?: string;
}
function isScreenshotResult(result: unknown): result is ScreenshotResult {
if (typeof result !== 'object' || result === null) return false;
const r = result as Record<string, unknown>;
return typeof r.image_data === 'string' && r.image_data.length > 0;
}
export function registerViewportTools(server: McpServer) {
// Tool 9: Get Screenshot
server.registerTool(
'blender_get_screenshot',
{
title: 'Capture Viewport Screenshot',
description: `Capture current viewport as base64 image.
Takes screenshot of current 3D viewport view. Limited to 800px max dimension for performance.
Args:
- max_size (optional): Maximum dimension in pixels (100-800, default: 800)
Returns:
Base64 encoded PNG image data with metadata
Use when: Visualizing scene state, checking results, debugging
Don't use when: Need high resolution renders (use Blender render instead)
Performance: Larger images take longer to process and transfer`,
inputSchema: GetScreenshotSchema,
annotations: {
readOnlyHint: true,
destructiveHint: false,
idempotentHint: true,
openWorldHint: false
}
},
async (params): Promise<ToolResult> => {
try {
const client = getBlenderClient();
const response = await client.sendCommand('get_viewport_screenshot', {
max_size: params.max_size
});
if (response.status === 'error') {
return {
content: [{ type: 'text', text: `Error: ${response.message || 'Failed to capture screenshot'}` }],
isError: true
};
}
// Validate and extract screenshot data
if (!isScreenshotResult(response.result)) {
return {
content: [{ type: 'text', text: 'Error: Invalid screenshot response - missing image data' }],
isError: true
};
}
const { image_data, width, height } = response.result;
const content: ToolContent[] = [];
// Add image content
content.push({
type: 'image',
data: image_data,
mimeType: 'image/png'
});
// Add metadata text
const dimensions = width && height ? `${width}x${height}` : `${params.max_size}px max`;
content.push({
type: 'text',
text: `Viewport screenshot captured (${dimensions})`
});
return { content };
} catch (error) {
return {
content: [{
type: 'text',
text: `Error: ${error instanceof Error ? error.message : 'Unknown error'}`
}],
isError: true
};
}
}
);
}
