echo-bar

Display status information in the Emacs echo area instead of the mode line, saving a line of screen real estate.

what’s the point

Most echo-area status packages use a timer that recomputes every segment on every tick, creates temporary buffers to measure pixel widths, and writes overlays even when nothing changed. That works, but it’s wasteful.

echo-bar takes a different approach: event-driven updates with coalescing. Each segment declares what triggers it (hooks, advice, idle timers). When a trigger fires, the segment is marked dirty and a single update is scheduled via run-at-time 0 nil. Only dirty segments recompute. Overlays are written only when the rendered string actually changes.

The result is a status bar that feels instant and doesn’t burn CPU in the background.

Install

echo-bar is not yet on MELPA. For now, clone the repo and point your config at it.

use-package + local path

(use-package echo-bar
:ensurenil:load-path"~/path/to/echo-bar":custom
(echo-bar-layout
'(:center ("buffer-position""buffer-name""major-mode")
:right ("project""vcs""time""battery")))
:config
(echo-bar-mode 1))

straight.el

(use-package echo-bar
:straight (:host github :repo"chenanton/echo-bar")
:custom
(echo-bar-layout
'(:center ("buffer-position""buffer-name""major-mode")
:right ("project""vcs""time""battery")))
:config
(echo-bar-mode 1))

elpaca

(use-package echo-bar
:ensure (:host github :repo"chenanton/echo-bar")
:custom
(echo-bar-layout
'(:center ("buffer-position""buffer-name""major-mode")
:right ("project""vcs""time""battery")))
:config
(echo-bar-mode 1))

Usage

(echo-bar-mode 1) ; enable
(echo-bar-mode -1) ; disable

Layout

echo-bar-layout is a plist mapping zone keys to lists of segment names. Three zones are supported:

Zone	Positioning
:left	Flush left
:center	Centered (clamped to avoid right)
:right	Right-aligned

You can combine them however you like:

;; Right only (simplest)
(setq echo-bar-layout
'(:right ("buffer-name""major-mode""vcs""time")))
;; Center + right
(setq echo-bar-layout
'(:center ("buffer-position""buffer-name""major-mode")
:right ("project""vcs""time""battery")))
;; Left + right
(setq echo-bar-layout
'(:left ("buffer-name""buffer-position")
:right ("major-mode""vcs""project""time")))

Other options

Variable	Default	Description
echo-bar-separator	" "	String between segments in a group
echo-bar-right-padding	1	Chars of padding before the right edge
echo-bar-center-right-gap	4	Min gap between center and right groups
echo-bar-time-format	"%a %b %-e %-I:%M %p"	Format string passed to format-time-string
echo-bar-idle-fallback-interval	2.0	Idle seconds before safety-net refresh

Faces

Every segment has a face you can customize. They all inherit from echo-bar-default (which inherits default) except echo-bar-dim (inherits shadow) and echo-bar-warning (inherits warning).

;; Example: make the buffer name bold
(set-face-attribute'echo-bar-buffer-namenil:weight'bold)

Or with use-package:

:custom-face
(echo-bar-buffer-name ((t (:inheritbold))))
(echo-bar-major-mode ((t (:inheritorg-level-4))))

Segments

Name	Shows	Scope	Trigger
buffer-name	Buffer name, [+] if dirty	buffer	post-command, save
buffer-position	Line:column	buffer	post-command
selection-info	Sel:3L,42C when region	buffer	post-command
narrow	Narrow when narrowed	buffer	post-command
macro	REC during kbd macro	buffer	post-command
process	Active process info	buffer	post-command
profiler	PROF when profiler runs	global	post-command
major-mode	Mode name	buffer	mode change
vcs	Branch name	buffer	file open/save, vc
project	Project name	buffer	file open
blame	Blame in magit-blame	buffer	blame mode hook
text-scale	Zoom:+2 when scaled	buffer	text-scale hook
repeat	REPEAT during repeat-mode	global	repeat-post-hook
time	Formatted date/time	global	idle timer
battery	Battery string	global	battery-update

Segments only appear when they have something to show. nil or "" means the segment is hidden and no separator is added.

Defining custom segments

(echo-bar-defsegment my-word-count
"Word count for the current buffer.":triggers (:hooks (post-command-hook))
:fn (format"%dW" (count-words (point-min) (point-max)))
:face echo-bar-dim)

Then add "my-word-count" to your layout.

Properties:

Key	Description
:fn	Body that returns a string (or nil to hide)
:face	Face applied to the output
:scope	:buffer (default) or :global
:triggers	Plist of :hooks, :advice, :timers
:setup	Body run once on first activation

Trigger types:

• :hooks – list of hook symbols (e.g. (post-command-hook after-save-hook))
• :advice – alist of (FUNCTION . HOW) pairs (e.g. ((vc-refresh-state . :after)))
• :timers – plist (:idle SECS :repeat BOOL) for idle-timer triggers

How it works

Traditional echo-area packages poll on a timer. echo-bar does this instead:

1. Trigger – A hook fires or advice runs. The associated segment is marked dirty.
2. Coalesce – run-at-time 0 nil schedules a single update. Multiple triggers in the same command cycle collapse into one call.
3. Recompute – Only dirty segments re-evaluate their :fn. Clean segments keep their cached output.
4. Render – Cached outputs are joined per zone and positioned with space :align-to display properties.
5. Write – The rendered string is compared to the last write. If it’s identical, the overlay is not touched.

Messages are truncated with … to fit alongside the bar. If you need the full message, check *Messages*.

Requirements

Emacs 29.1 or later. No external dependencies.

Alternatives

• mini-echo – Similar concept, more segments out of the box. Uses a 300ms timer for updates.
• awesome-tray – Another echo-area status bar.
• doom-modeline – Not an echo-area package, but a well-optimized modeline with hook-cached segments. Good reference for the approach.

License

GPL-3.0-or-later. See LICENSE.