Probe Media File

Instructions

Implementation Reference

• src/tools/media.ts:6-25 (registration)

  Registration of the 'media_probe' tool via server.registerTool(), called from src/index.ts line 21.

  export function registerMediaTools(server: McpServer) {
    server.registerTool(
      'media_probe',
      {
        title: 'Probe Media File',
        description: 'Use ffprobe to inspect a video/audio/image file under VIDEO_FACTORY_ROOT.',
        inputSchema: z.object({ inputPath: z.string() })
      },
      async ({ inputPath }) => {
        try {
          const input = safePath(inputPath);
          const args = ['-v', 'error', '-show_format', '-show_streams', '-of', 'json', input];
          const result = await runCommand(config.ffprobeBin, args);
          if (result.code !== 0) return errorResult('ffprobe failed', result.stderr);
          return textResult(JSON.parse(result.stdout));
        } catch (err) {
          return errorResult('Failed to probe media', String(err));
        }
      }
    );

• src/tools/media.ts:14-24 (handler)

  Handler function that uses ffprobe to inspect a media file under VIDEO_FACTORY_ROOT. Runs ffprobe with -show_format and -show_streams flags, parses JSON output, and returns results or errors.

  async ({ inputPath }) => {
    try {
      const input = safePath(inputPath);
      const args = ['-v', 'error', '-show_format', '-show_streams', '-of', 'json', input];
      const result = await runCommand(config.ffprobeBin, args);
      if (result.code !== 0) return errorResult('ffprobe failed', result.stderr);
      return textResult(JSON.parse(result.stdout));
    } catch (err) {
      return errorResult('Failed to probe media', String(err));
    }
  }

• src/tools/media.ts:9-13 (schema)

  Input schema for media_probe: requires a single string inputPath (path relative to VIDEO_FACTORY_ROOT).

  {
    title: 'Probe Media File',
    description: 'Use ffprobe to inspect a video/audio/image file under VIDEO_FACTORY_ROOT.',
    inputSchema: z.object({ inputPath: z.string() })
  },

• src/config.ts:28-35 (helper)

  safePath helper used by the handler to resolve and validate the input path stays within VIDEO_FACTORY_ROOT.

  export function safePath(input: string) {
    ensureRoot();
    const resolved = path.resolve(config.root, input);
    if (!resolved.startsWith(config.root)) {
      throw new Error(`Path escapes VIDEO_FACTORY_ROOT: ${input}`);
    }
    return resolved;
  }

• src/utils.ts:15-24 (helper)

  runCommand helper used by the handler to execute ffprobe as a subprocess.

  export function runCommand(command: string, args: string[], cwd?: string): Promise<{ code: number; stdout: string; stderr: string }> {
    return new Promise((resolve) => {
      const child = spawn(command, args, { cwd, shell: false });
      let stdout = '';
      let stderr = '';
      child.stdout.on('data', (d) => (stdout += d.toString()));
      child.stderr.on('data', (d) => (stderr += d.toString()));
      child.on('close', (code) => resolve({ code: code ?? -1, stdout, stderr }));
    });
  }