fern

command module
v1.1.0-beta Latest Latest
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 Go to latest Published: Apr 15, 2026 License: AGPL-3.0 Imports: 9 Imported by: 0

README

Fern

Go Reference Go Report Card

Made with VHS

A vim-style markdown notebook for the terminal. Create and manage notes, daily journals, and templates in a local vault with full-text search, wikilinks, and a keyboard-driven interface, all without leaving your shell. Your data stays private on your machine. No cloud. No account required.

Features

  • Vim-like editing modes: Normal, Insert, Replace, and Visual modes with an indicator in the command bar
  • Notes, Journals & Templates: daily, weekly, monthly, and yearly journal entries; templates to keep new notes consistent
  • Wikilinks & Markdown links: links are automatically rewritten when notes are renamed. No more dead links!
  • Full-text search: regex-compatible search across your entire vault (/)
  • Command palette: fuzzy-searchable palette for quick access to all commands (ctrl+p)
  • Collapsible sidebar tree: tree directory over Notes, Journals, and Templates subfolders (ctrl+b)
  • Tabs & split panes: open multiple notes side-by-side or in tabs, move tabs between panes
  • Bookmarks: save and re-open important tabs quickly
  • Themes: comes with a set of popular themes, pride flag themes, & support for your own custom JSON themes. Add them in a PR for others to enjoy too!
  • Configurable keybindings: remap any action shortcuts in User config file
  • Multiple vaults: create and switch between vaults on the fly
  • Local-first: no telemetry, no cloud sync service; runs well on resource-constrained systems

Installation

Binary Releases

For Windows, Mac OS(10.12+) or Linux, you can download a pre-built binary release here.

Homebrew (macOS and Linux)
brew tap InodeLabs/tap https://codeberg.org/InodeLabs/homebrew-tap
brew install --cask fern
Scoop (Windows)
scoop bucket add InodeLabs https://codeberg.org/InodeLabs/scoop-bucket
scoop install fern
Linux packages (DEB / RPM)

Pre-built .deb and .rpm packages are available on the releases page.

# Debian / Ubuntu
sudo dpkg -i fern_*.deb

# Fedora / RHEL / openSUSE
sudo rpm -i fern_*.rpm
# or with dnf:
sudo dnf install fern_*.rpm
Go

go install codeberg.org/InodeLabs/fern@latest

NOTE: If you get an error that fern cannot be found or that it is not defined, you may need to add ~/go/bin to your $PATH (for macOS/Linux). On Windows, add %HOME%\go\bin, not to be confused with C:\Go\bin, which is for Go's own binaries, not apps like fern.

Manual

You will need to have Go installed first.

git clone https://codeberg.org/InodeLabs/fern
cd fern
go install

Using Fern

Run fern in your terminal to launch the TUI. On first run you will be prompted to set up a new vault or point Fern at an existing one.

Try the Demo Vault!

Meet Fern(she/her). She's a transfem 🏳️‍⚧️, tech worker 👩🏽‍💻 who is just trying to keep her head above water and get organised in today's crazy world. Good thing she has Fern! Her vault* contains some example notes (cross-linked), along with sample journals, templates, and bookmarks. This demo vault can be found in the demo folder (I'm not so creative in names, sorry). For an orientation to the Vault and a tour of some of Fern's main features, open the start-here.md in the sidebar, under the Notes section! Have fun and explore all of Fern's features without needing to set up a new vault or touch any of your existing notes.

After installing Fern, you can load it:

  • From the CLI: by running fern open ./demo
  • From inside Fern: by running the vaultLoad command: :vaultLoad ./demo

*All notes, journals, etc are purely fictional. McBoatface is not a real politician, to my knowledge!

Command Bar

Press : from anywhere outside of Insert/Replace mode to open the command bar. Commands support tab-completion and do the same things as their palette equivalents. New command features usually land here first.

Notes
Command Action
:noteOpen <name> Open a note
:noteAdd <name> Create a new note
:noteRename <name> Rename the current note
:noteDelete Delete the current note
Journals
Command Action
:journalOpen <ref> Open a journal entry (today, yesterday, tomorrow, this-week, last-week, next-week, this-month, last-month, this-year, last-year, or a date like 2025-03-15)
:journalReview day|week|month|year Open a period's journal entries
:journalDelete <ref> Delete a journal entry
Templates
Command Action
:templateAdd <name> Create a new template
:templateOpen <name> Open a template
:templateRename <name> Rename a template
:templateDelete <name> Delete a template
Bookmarks
Command Action
:bookmarkAdd <name> Bookmark the current tab
:bookmarkEdit Edit all bookmarks
:bookmarkOpen <name> Open a bookmarked tab
Vaults
Command Action
:vaultLoad <name> Load a vault
:vaultCreate <path> Create a new vault
Command Action
:search <query> Full-text search vault (regex compatible)
:w Save
:wq Save and quit
:q / :q! Quit / force quit
:reload Reload file from disk
:recover Recover from swap file after a crash

Configuration

Fern reads its config from ~/.config/fern/config (or$XDG_CONFIG_HOME/fern/config). The file is created automatically on first run with every option present and commented out. Uncomment and edit any line to override the default. Additionally, there are vault-level configuration files (stored in a folder .fern/config inside each vault) that overrides global user settings, allowing for vault-specific configurations that travel with your vault.

Keybindings

All bindings are customisable in the user config file. The defaults are shown below. If they are too vim-y, make them emacs-y. Hate both those? Do something totally different! Got an idea for a shortcut? Please reach out!

Navigation
Key Action
Tab / Shift+Tab Cycle focus between sidebar and viewer
ctrl+b Toggle sidebar
ctrl+p Command palette
ctrl+e Toggle Mode View <--> Edit(Normal)
/ Search vault
: Open command bar
? Help (keybinding reference in-app)
ctrl+q Quit
Sidebar
Key Action
j / k Move cursor down / up
l / → / Space Expand directory
h / ← Collapse directory or jump to parent
Enter Toggle directory / open file
1 Jump to Notes section
2 Jump to Journals section
3 Jump to Templates section
View Mode
Key Action
j / k Scroll down / up
ctrl+d / ctrl+u Half-page down / up
gg Go to top
G Go to bottom
l / → Expand fold
h / ← Collapse fold
Normal Mode (edit)
Key Action
h / j / k / l or arrow keys Move cursor left / down / up / right
ctrl+← / ctrl+→ Word backward / forward
0 / $ Start / end of line
gg / G Top / bottom
ctrl+d / ctrl+u Half-page down / up
i Insert mode (before cursor)
a Insert mode (after cursor)
I Insert mode at first non-blank character
A Insert mode at end of line
R Replace mode (overwrite characters)
o / O New line below / above, enter Insert mode
r Replace single character
x Delete character under cursor
dd / dw Delete line / word
cw / cW Change word
u / ctrl+z Undo
ctrl+r / ctrl+y Redo
v / V Visual / Visual-line mode
p / ctrl+v Paste from register
t Toggle checkbox state
T Insert a new checkbox
gf Open link under cursor
ctrl+e Back to View mode
Insert Mode
Key Action
Insert Toggle to Replace mode
Tab Insert tab (respects tab_spaces config)
Enter New line (auto-continues lists)
ctrl+s Save and return to Normal mode
Esc Return to Normal mode (without saving)
Replace Mode

Replace mode overwrites characters in place as you type, like pressing Insert in most editors.

Key Action
Insert Toggle to Insert mode
Backspace Delete previous character
ctrl+s Save and return to Normal mode
Esc Return to Normal mode
Visual Mode
Key Action
y / ctrl+c Yank (copy) selection
d / x Cut selection
c Change (cut and enter Insert mode)
r Replace selection with next typed character
s Search vault for selected text
v / V Switch between character / line selection
Esc Cancel (return to Normal mode)
Tabs & Split Panes

Tabs

Key Action
[ / ] Previous / next tab
{ / } Move tab left / right
ctrl+w Close active tab

Split Panes

Key Action
ctrl+w v Split pane vertically
ctrl+w s Split pane horizontally
ctrl+w q / ctrl+w c Close the active pane
ctrl+h / j / k / l Move focus to pane left / down / up / right
alt+h / j / k / l Move active tab to adjacent pane

Project Roadmap

Here's a near-term list of things, and very-rough release plan, for features I'm hoping to work on adding to Fern:

v1.1
  • Easier Themes Setup: Currently, unless users install from source with make install there's manual steps needed to get themes generated and setup. This needs to be easier/eliminated!
  • Change UI Language: I will try to add Spanish & Japanese translations (very crude/basic! only ones I know well enough) for a start. Will think hard about how to make it something the community can add to, grow, and maintain.
v1.2
  • Update Settings in-app: No more fiddling with configuration files (if you don't want to that is). Thinking a modal with two tabs for Global(user) & Vault settings.
v1.3
  • Visualize your Vault's Graph: Have a way to export your vault's notes/journals connections graph.
  • Right sidebar: could hold note/vault stats, outbound and inbound links for the active note, etc. I'm all ears if you have ideas for what could/should live in this space!
v1.4

And mor! Open an issue for any features you want to see!

To Contributors

We use golangci-lint and gocyclo as part of our Git pre-commit hook flow and for formatting and linting via the Makefile.

Please ensure you have both installed:

# golanci-lint Docs: https://golangci-lint.run/docs/welcome/install/local/
curl -sSfL https://golangci-lint.run/install.sh | sh -s -- -b $(go env GOPATH)/bin latest
# gocyclo Docs: https://github.com/fzipp/gocyclo
go install github.com/fzipp/gocyclo/cmd/gocyclo@latest

Found a bug? Got an idea for a new feature?

Please open a ticket at https://codeberg.org/InodeLabs/fern/issues.

Documentation

Overview

Fern is a vim-style markdown note manager.

Source Files

View all Source files

Directories

Path Synopsis
cmd
themegen command
themegen writes JSON theme files to the themes directory at project root.
 themegen writes JSON theme files to the themes directory at project root.
internal
bookmark
Package bookmark manages the vault bookmark file.
 Package bookmark manages the vault bookmark file.
commands
Package commands provides pure functions for vault file operations.
 Package commands provides pure functions for vault file operations.
config
Package config loads, parses, and holds Fern's runtime configuration.
 Package config loads, parses, and holds Fern's runtime configuration.
debug
Package debug provides lightweight file-based debug logging for development.
 Package debug provides lightweight file-based debug logging for development.
i18n
Package i18n provides runtime-switchable UI string translations.
 Package i18n provides runtime-switchable UI string translations.
journal
Package journal resolves and creates periodic journal log files.
 Package journal resolves and creates periodic journal log files.
search
Package search provides full-text grep-style search over vault files.
 Package search provides full-text grep-style search over vault files.
template
Package template applies date-variable substitution to note templates.
 Package template applies date-variable substitution to note templates.
tests
Package tests provides helpers for use in table-driven tests.
 Package tests provides helpers for use in table-driven tests.
theme
Package theme loads and resolves built-in and custom UI themes.
 Package theme loads and resolves built-in and custom UI themes.
tui
Package tui is the top-level Bubble Tea application model.
 Package tui is the top-level Bubble Tea application model.
tui/bookmarkeditor
Package bookmarkeditor is a TUI component for editing vault bookmarks.
 Package bookmarkeditor is a TUI component for editing vault bookmarks.
tui/cmdbar
Package cmdbar is the command/status bar TUI component.
 Package cmdbar is the command/status bar TUI component.
tui/common
Package common holds shared types and styles used across TUI components.
 Package common holds shared types and styles used across TUI components.
tui/dialog
Package dialog is a modal yes/no confirmation dialog TUI component.
 Package dialog is a modal yes/no confirmation dialog TUI component.
tui/palette
Package palette is the command-palette TUI component.
 Package palette is the command-palette TUI component.
tui/searchmodal
Package searchmodal is the full-text search modal TUI component.
 Package searchmodal is the full-text search modal TUI component.
tui/sidebar
Package sidebar is the file-browser sidebar TUI component.
 Package sidebar is the file-browser sidebar TUI component.
tui/templateprompt
Package templateprompt is a TUI prompt for selecting note templates.
 Package templateprompt is a TUI prompt for selecting note templates.
tui/viewer
Package viewer is the main markdown viewer/editor TUI component.
 Package viewer is the main markdown viewer/editor TUI component.
vault
Package vault provides helpers for creating and inspecting vaults.
 Package vault provides helpers for creating and inspecting vaults.
vfiles
Package vfiles maintains an SQLite index of vault files and their metadata.
 Package vfiles maintains an SQLite index of vault files and their metadata.
Package themes embeds the distributed theme JSON files into the binary.
 Package themes embeds the distributed theme JSON files into the binary.

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