MCP File Forge

Instructions

Implementation Reference

• src/tools/metadata.ts:114-196 (handler)

  Implementation of the file_exists tool logic.

  async function fileExistsImpl(input: FileExistsInput): Promise<ToolResult> {
    try {
      const absolutePath = path.resolve(input.path);
  
      try {
        const stats = await fs.stat(absolutePath);
  
        // Check type if specified
        if (input.type === 'file' && !stats.isFile()) {
          return {
            content: [
              {
                type: 'text',
                text: JSON.stringify({
                  exists: false,
                  path: absolutePath,
                  reason: 'Path exists but is not a file',
                  actualType: stats.isDirectory() ? 'directory' : 'other',
                }),
              },
            ],
          };
        }
  
        if (input.type === 'directory' && !stats.isDirectory()) {
          return {
            content: [
              {
                type: 'text',
                text: JSON.stringify({
                  exists: false,
                  path: absolutePath,
                  reason: 'Path exists but is not a directory',
                  actualType: stats.isFile() ? 'file' : 'other',
                }),
              },
            ],
          };
        }
  
        return {
          content: [
            {
              type: 'text',
              text: JSON.stringify({
                exists: true,
                path: absolutePath,
                isFile: stats.isFile(),
                isDirectory: stats.isDirectory(),
              }),
            },
          ],
        };
      } catch {
        return {
          content: [
            {
              type: 'text',
              text: JSON.stringify({
                exists: false,
                path: absolutePath,
              }),
            },
          ],
        };
      }
    } catch (error) {
      const err = error as Error;
  
      return {
        isError: true,
        content: [
          {
            type: 'text',
            text: JSON.stringify({
              code: 'UNKNOWN_ERROR',
              message: `Error checking existence: ${err.message}`,
            }),
          },
        ],
      };
    }
  }

• src/tools/metadata.ts:458-469 (registration)

  Registration of the file_exists tool in the MCP server.

  server.tool(
    'file_exists',
    'Check if a file or directory exists',
    {
      path: z.string().describe('Path to check'),
      type: z.enum(['file', 'directory', 'any']).optional().describe('Type to check for'),
    },
    async (args) => {
      const input = FileExistsInputSchema.parse(args);
      return await fileExistsImpl(input);
    }
  );

• src/types.ts:250-250 (schema)

  Input schema definition for file_exists tool.

  export const FileExistsInputSchema = z.object({