it-tools-mcp/build/tools/data_format/format_json/index.js

MCP-compliant server access to over 100 IT tools and utilities commonly used by developers, system administrators, and IT professionals.

import { z } from "zod";
export function registerFormatJson(server) {
    server.registerTool("format_json", {
        inputSchema: {
            json: z.string().describe("JSON string to format"),
            indent: z.number().describe("Number of spaces for indentation").optional(),
        },
        // VS Code compliance annotations
        annotations: {
            title: "Format JSON",
            readOnlyHint: false
        }
    }, async ({ json, indent = 2 }) => {
        try {
            if (indent < 0 || indent > 10) {
                return {
                    content: [
                        {
                            type: "text",
                            text: "Indent must be between 0 and 10.",
                        },
                    ],
                };
            }
            // Try to normalize JavaScript-style object notation to valid JSON
            let normalizedJson = json.trim();
            // Handle single quotes by converting to double quotes
            // This is a simplified approach that works for most common cases
            try {
                // First try parsing as-is
                const parsed = JSON.parse(normalizedJson);
                const formatted = JSON.stringify(parsed, null, indent);
                return {
                    content: [
                        {
                            type: "text",
                            text: `Formatted JSON:\n${formatted}`,
                        },
                    ],
                };
            }
            catch (firstError) {
                // If parsing fails, try to normalize the format
                try {
                    // Convert single quotes to double quotes for property names and string values
                    // This handles simple cases like {'name':'John','age':30}
                    normalizedJson = normalizedJson
                        .replace(/'/g, '"') // Replace single quotes with double quotes
                        .replace(/([{,]\s*)([a-zA-Z_$][a-zA-Z0-9_$]*)\s*:/g, '$1"$2":'); // Quote unquoted property names
                    const parsed = JSON.parse(normalizedJson);
                    const formatted = JSON.stringify(parsed, null, indent);
                    return {
                        content: [
                            {
                                type: "text",
                                text: `Formatted JSON (normalized from JavaScript object notation):\n${formatted}`,
                            },
                        ],
                    };
                }
                catch (secondError) {
                    // Security: Do NOT use Function() constructor or eval() as they enable code injection
                    // Only JSON.parse() should be used - it's safe and sufficient for JSON formatting
                    return {
                        content: [
                            {
                                type: "text",
                                text: `Error parsing JSON: ${firstError instanceof Error ? firstError.message : 'Unknown error'}

Attempted normalization failed: ${secondError instanceof Error ? secondError.message : 'Unknown error'}

Please ensure your input is valid JSON.

Supported format:
- Valid JSON: {"name":"John","age":30}

Note: For security reasons, JavaScript object literals and code evaluation are not supported.
Please convert your input to valid JSON format before formatting.`,
                            },
                        ],
                    };
                }
            }
        }
        catch (error) {
            return {
                isError: true,
                content: [
                    {
                        type: "text",
                        text: `Error formatting JSON: ${error instanceof Error ? error.message : 'Unknown error'}`,
                    },
                ],
            };
        }
    });
}