[description] Blobs usually represent the content of a file. But on their own, they don't have any metadata, not even a name! Git has a very powerful concept to store metadata related to blobs: the index! It's a list that relates blobs to filenames and access permissions. The most convenient option to add an entry to the index is via an existing file: echo "my content" > file git update-index --add file Add three entries to the index! For a bonus challenge: can you add a file that is inside of a directory, like "directory/file"? [congrats] There's another way to add an entry to the index directly: git update-index --add --cacheinfo ,, The first three numbers of the mode describe the type of the entry, "100" is a regular file. The second three number describe the permissions. Only "644" (non-executable) and "755" (executable) are supported. You can insert the hash of an object into the terminal by right-clicking on it! :) [setup] [setup goal] echo "file 1" > file1 echo "file 2" > file2 echo "file 3" > file3 git add . [win] test "$(git ls-files | wc -l)" -ge 3