json-mcp-server

Instructions

Implementation Reference

• src/index.ts:161-208 (handler)

  The handler for the 'split' tool. It validates input, reads a JSON file, splits its array into multiple files each containing up to numObjects items, writes them as part1.json, part2.json etc., and returns a success message.

  case 'split': {
    const parsed = SplitArgSchema.safeParse(args)
    if (!parsed.success) {
      throw new Error(`Invalid arguments for split: ${parsed.error}`)
    }
    const { path, numObjects } = parsed.data
  
    const validPath = await validatePath(path)
    const content = await fs.promises.readFile(validPath, 'utf-8')
    const folder = await getParentDir(path)
  
    const jsonData = JSON.parse(content)
  
    if (numObjects >= jsonData.length / 2) {
      throw new Error(
        `The number of objects (${numObjects}) per file cannot be half or more of the total (${jsonData.length}) JSON data length.`
      )
    }
  
    const totalParts = Math.ceil(jsonData.length / numObjects)
  
    await Promise.all(
      Array.from({ length: totalParts }, async (_, i) => {
        const partArray = jsonData
          .slice(i * numObjects, (i + 1) * numObjects)
          ?.flat()
        const partFileName = _path.join(folder, `part${i + 1}.json`)
        try {
          await fs.promises.writeFile(
            partFileName,
            JSON.stringify(partArray, null, 2)
          )
          console.log(`Successfully wrote ${partFileName}`)
        } catch (err) {
          console.error(`Error writing file ${partFileName}:`, err)
        }
      })
    )
  
    return {
      content: [
        {
          type: 'text',
          text: `Successfully splitted to ${parsed.data.path}`,
        },
      ],
    }
  }

• src/index.ts:43-46 (schema)

  Zod schema defining the input arguments for the split tool: path (string) and numObjects (positive integer).

  const SplitArgSchema = z.object({
    path: z.string(),
    numObjects: z.number().int().positive(),
  })

• src/index.ts:142-146 (registration)

  Registration of the 'split' tool in the ListTools response, including name, description, and input schema.

  {
    name: 'split',
    description: 'Split a JSON file into a specified number of objects',
    inputSchema: zodToJsonSchema(SplitArgSchema) as ToolInput,
  },