Termless

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Tape Format Reference ​

The .tape format is a line-based DSL for scripting terminal sessions. It is compatible with VHS by Charmbracelet, but termless adds headless execution and multi-backend playback.

Overview ​

A .tape file is a sequence of commands, one per line. Blank lines and comments (lines starting with #) are ignored.

tape
# This is a comment
Set FontSize 14
Set Width 1200
Set Height 600

Type "echo hello world"
Enter
Sleep 1s
Screenshot

Commands ​

Type ​

Type text characters into the terminal. Text must be quoted.

tape
Type "hello world"
Type "echo 'foo bar'"

Typing Speed ​

Control how fast characters are typed with Type@<speed>:

tape
Type@50ms "slow typing"
Type@10ms "fast typing"
Type@200ms "very slow, dramatic typing"

Key Commands ​

Press special keys. These are case-insensitive.

tape
Enter
Tab
Space
Backspace
Delete
Escape

Arrow Keys ​

tape
Up
Down
Left
Right
tape
Home
End
PageUp
PageDown

Repeat Count ​

Press a key multiple times:

tape
Down 5
Tab 3

Modifier Keys ​

Combine with Ctrl+ or Alt+:

tape
Ctrl+c
Ctrl+z
Ctrl+a
Alt+x
Alt+f

Sleep ​

Pause execution for a duration:

tape
Sleep 2s
Sleep 500ms
Sleep 0.5s

Screenshot ​

Capture a screenshot of the current terminal state:

tape
# Screenshot with auto-generated path
Screenshot

# Screenshot to a specific file
Screenshot /tmp/demo.png

Hide / Show ​

Control whether terminal output is visible during playback. Useful for skipping setup steps in animations:

tape
Hide
Type "npm install"
Enter
Sleep 5s
Show
Type "npm start"
Enter
Screenshot

Source ​

Include commands from another tape file:

tape
Source setup.tape
Type "my-command"
Enter
Screenshot

Require ​

Assert that a program is available before running the tape:

tape
Require node
Require bun
Type "bun run dev"
Enter

Output ​

Declare output file paths (VHS compatibility). In termless, prefer the -o CLI flag instead:

tape
Output demo.gif
Output demo.png

Settings ​

Configure the terminal environment with Set:

Terminal Size ​

tape
Set Width 1200
Set Height 600

Font ​

tape
Set FontSize 14
Set FontFamily "Menlo"

Shell ​

tape
Set Shell "bash"
Set Shell "/bin/zsh"

Theme ​

tape
Set Theme "Dracula"
Set Theme "Monokai"

Typing Speed ​

Default speed for all Type commands:

tape
Set TypingSpeed 50ms

Duration Format ​

Duration values are used in Sleep, Type@, and Set TypingSpeed:

FormatMeaningExample
NsN seconds2s, 0.5s
NmsN milliseconds500ms, 100ms
NN milliseconds (bare number)200

Full Example ​

tape
# Demo: build pipeline status
Set Shell "bash"
Set FontSize 14
Set Width 1200
Set Height 600

# Hide the setup
Hide
Type "cd ~/myproject"
Enter
Sleep 500ms
Show

# Show the build
Type "npm run build"
Enter
Sleep 2s
Screenshot build-start.png

# Navigate the output
Down 5
Sleep 500ms
Screenshot build-done.png

Running Tape Files ​

bash
# Play a tape and see the output
$ termless play demo.tape

# Play and generate a GIF
$ termless play -o demo.gif demo.tape

# Play against a specific backend
$ termless play -b ghostty demo.tape

# Play with cross-terminal comparison
$ termless play -b vterm,ghostty --compare side-by-side demo.tape

VHS Compatibility ​

The termless tape parser is compatible with VHS .tape files. The main differences:

  • Execution is headless -- no GUI window, no ffmpeg dependency
  • Multi-backend -- play against any of 10+ terminal emulators
  • Output formats -- GIF, animated SVG, APNG, PNG, asciicast (all pure JS, no ffmpeg)
  • Cross-terminal comparison -- side-by-side, grid, diff modes

See Also ​