fnc: interactive text-based user interface for Fossil

fnc uses ncurses and libfossil to create a fossil ui experience in the terminal, and parse local changes at the hunk level to prepare atomic commits.

Tested and confirmed to run on the following amd64 systems (additional platforms noted inline):

  1. OpenBSD 6.8–7.4-{current,release}
  2. macOS Catalina 10.15.7, Big Sur 11.5.2, and Ventura 13.6.1
  3. Linux Mint 20.2 (32- and 64-bit ARM)
  4. Ubuntu 18.04, 21.04, 21.10, and 22.04 running Linux 5.1{1,3} (32-bit ARM)
  5. Debian GNU/Linux 8, 9, and 10
  6. CentOS 6.5 (32-bit)
  7. Alpine Linux 3.19_rc1

Alpha development notwithstanding, the timeline, diff, tree, blame, branch, and stash commands are relatively stable; however, there is no commitment to refrain from breaking changes.


Packaging status

Check repology to find if a package is provided for your operating system. If no package exists, download and install the binary on your path.


  1. clone the repository
    • fossil clone https://fnc.bsdbox.org
  2. move into the repository checkout
    • cd fnc
  3. build fnc
    • make
  4. install the fnc binary (requires privileges)
    • doas make install
  5. move into an open Fossil checkout, and run it:
    • cd ~/museum/repo && fossil open ../repo.fossil && fnc

This will install the fnc executable and man page into /usr/local/bin and /usr/local/share/man/man1, respectively. Alternatively, cryptographically signed tarballs of the source code and binaries for some of the abovementioned platforms are available to download.


Commands available in fnc:

  1. stash
    • interactively select hunks to stash from the diff of local changes on disk
  2. timeline
    • hyperlinked chronological commit history of the repository
  3. diff
    • diff of all changes between commits or blobs
  4. blame
    • annotated file displaying commit attribution history of each line
  5. tree
    • navigable file hierarchy of the repository tree
  6. branch
    • hyperlinked list of all public and private branches
  7. config
    • configure or view fnc settings

See fnc --help for a quick reference, and the fnc(1) manual page for more comprehensive documentation. Runtime help can also be accessed with the ?, F1, or H key binding. There are screenshots that illustrate various views, and the following video briefly demonstrates some of the key bindings in use.

fnc demo


fnc is heavily inspired by tog, which I missed when I left Got behind and started using Fossil. The objective is to provide an alternative to fossil ui without leaving the terminal.

Problems & Patches

Please submit bug reports via email, the forum, or by creating a new ticket. As a rule, all reports should include a bug reproduction recipe; that is, either (1) the series of steps beginning with fossil init to create a new repository through to the fnc command that triggers the unexpected behaviour; or, if possible, (2) a shell script that contains all necessary ingredients to reproduce the problem.

Patches are thoughtfully considered and can be sent to the mailing list. While diff -up patches (or fnc diffs saved with the P keymap) are preferred, fossil patch create and fossil diff patches are also welcomed. Please ensure code conforms to the C99 standard, and complies with OpenBSD's KNF style(9). Any patch containing user-visible code addition, modification, or deletion (i.e., code that impacts user interfaces) should concomitantly include updating documentation affected by the change.


fnc [fɪŋk]
noun (n.)
1. an interactive ncurses browser for Fossil repositories
verb (v.)
2. to inform
From the German word Fink, meaning "finch", a type of bird.