EVP is a Rust CLI tool to make beautiful terminal recordings from a list of input events.
You write a .tape file and run evp my_sript.tape to produce smooth, high quality, portable GIF or SVG demos.
EVP is a rewrite of VHS with some key improvements.
See it in action at flyline or below:
EVP is extends VHS in these ways:
- Significantly faster. No more skipped frames when creating demos in GHA!
- Animated SVGs:
- Super crisp demos
- You can select and copy text from the SVG as it is playing!
- Fonts are embedded into the SVG so the demos are portable (fonts are subsetted before embedding)
- SVG screenshots
- Box-drawing chars are rendered as SVG shapes. Don't worry, an invisible character is written to the SVG so selecting and copying text works as expected.
- Supports Kitty extended keycodes. e.g:
Ctrl+Shift+Alt+LeftCommand+Alt+PageUp
- Specify full shell path with arguments. e.g.:
Set Shell bash --init-file test.rcSet Shell yaziyou can specify and program, not just a shell!
- EVP has no runtime dependencies
- It is a statically linked musl binary
- A collection of useful fonts are embedded into EVP
- Mouse support: you can script mouse input (clicking, dragging, mouse moving)
- Set the terminal size by number of rows / cols or by number of pixels.
- Coming soon: resize support
- Coming soon: snapshot process metrics to help debug interactive use
- Coming soon: key event name overlay
EVP runs a shell inside an embedded libghostty terminal. This allows us to support advanced terminal features in a headless environment such as: complex key combinations; key press and key release events; mouse input support; legacy escape codes.
The SVG animations are done using SMIL.
Fonts are embedded into the SVG using this method.
A custom optimizer reduces the file size and complexity.
All the text on one terminal row is rendered inside of a <text> span which helps the browser copy the right text when you select and copy from the SVG.
GIF rendering is powered by gifski.
Tip
No sudo required!
curl -sSfL https://raw.githubusercontent.com/HalFrgrd/evp/master/install.sh | sh> docker bake extract-libghostty
> cargo build # Start from a base script:
> evp print-ref-script > demo.tape
# Modify the script then run it!
> evp demo.tapeOr if you already have a VHS script:
> evp --mimic-vhs demo.tapeTODO: make it possible to record user input and generate a tape from that.
evp record --output demo.gif, type away, use the mouse, then exit. Maybe we should automatically cut put the "exit + enter" part after a Hide.
The script should have a the refernece at the top.
TODO
TODO
EVP supports a superset of VHS .tape script language. Below is a complete template of all supported commands, settings, and events in the EVP .tape script language:
# --- Output & Dependencies ---
Output demo.gif # Target output file (supports .gif, .svg, .svgz, .json, .stats)
Output demo.json # Multiple outputs are supported. You can use the `--ouput demo.svg` flag also.
Output demo.svg # Recommended
Output demo.svgz # gzip-compressed svg, less widely supported
Output demo.stats # Reports some stats about the rendering process
Require curl # Assert that curl is available on system PATH
Source common.tape # Inline another tape file
# --- Window & Font Settings ---
Set Shell bash # Configure shell execution path (e.g. bash, zsh, fish)
Set Shell bash --norc # EVP supports any command as the "shell"
Set Shell yazi # You can boot right into your TUI
Set Theme "Catppuccin Mocha" # Apply a predefined colour theme (run `evp themes` to discover themes)
Set Font "JetBrains Mono" # Monospace font family name
Set FontSize 20 # Font size in pixels
Set LineHeight 1.2 # Line spacing multiplier
Set LetterSpacing 0 # Letter spacing adjustment
Set Width 800 # Terminal window width in pixels
Set Height 400 # Terminal window height in pixels
Set Cols 100 # Set terminal width in rows (Set Width has precedence)
Set Rows 30 # Set terminal height in rows (Set Height has precedence)
Set Padding 10 # Inner padding between terminal grid and window frame
Set Margin 20 # Outer margin around window frame
Set MarginFill "#6B50FF" # Background colour of outer margin area
Set Framerate 30 # Recording framerate in FPS
Set TypingSpeed 50ms # Default speed/interval for typed text
# --- Child Process Environment ---
Env PS1 "$ " # Set environment variables for the shell process
# --- Playback & Timeline Controls ---
Sleep 1s # Pause playback for a duration (e.g. 500ms, 1.5s, 2m)
Hide # Hide subsequent commands from recording output
Show # Resume recording commands to output files
Screenshot frame.png # Capture the current terminal window frame as a PNG, SVG, or JSON
Screenshot frame.svg
Screenshot frame.json
# --- Clipboard Controls ---
Copy "text to clipboard" # Copy a string into the system clipboard
Paste # Paste current clipboard contents into terminal
# --- Keyboard & Input Events ---
Type "echo 'hello'" # Type text at the current default TypingSpeed
Type@10ms "fast typing" # Type text at an overridden speed of 10ms
Enter # Press key alias (equivalent to Key "Enter" / Key "Return")
Backspace 5 # Repeat a key alias N times (press Backspace 5 times)
Ctrl+C # Press key combination modifier
Ctrl+Shift+Alt+Left # Even complex key codes are possible.
Press Down # Explicitly hold a key down
Release Down # Explicitly release a held key
# --- Mouse Controls ---
Click 10 20 # Left click at column 10, row 20
RightClick 10 20 # Right click at column 10, row 20
DoubleClick 10 20 # Double click at column 10, row 20
MouseMove@100ms 0 0 10 10 # Move cursor from (0,0) to (10,10) using default sigmoid (EaseInOutCubic) easing
MouseMove@100ms@EaseInOutElastic 0 0 10 10 # Move cursor with EaseInOutElastic easing curve override
MouseDrag@EaseInOutQuad 0 0 10 10 # Left click and drag with EaseInOutQuad easing curve
MouseScroll 10 20 Up # Scroll mouse wheel Up or Down at column 10, row 20
# --- Wait / Synchronization ---
Wait "Ready" # Wait for output matching text pattern
Wait /regex/ # Wait for output matching regular expression
Wait+Screen /regex/ # Wait scanning full screen instead of only the last line
Wait+Line /regex/ # Explicitly wait scanning last line only (default)
Wait@1s /regex/ # Wait with an overridden timeout of 1s (default is 15s)
Wait+Line@1s /regex/ # Wait scanning last line with 1s timeout override
Wait+Screen@1s /regex/ # Wait scanning full screen with 1s timeout overrideHere is a showcase of features and examples built with evp.
You can enable a window bar styled with macOS-like window controls and dynamically update the title displayed at the center of the bar. Your program will need to use OSC 2 or OSC 0 to set the title.
# Enable window bar styling
Set WindowBar Rings
# Set a dynamic terminal title via ANSI OSC sequence
Type "printf '\033]2;My Dynamic Terminal Title\007'"
Enter
EVP is based on the vhs project.
They share little code but EVP does try use the same .tape file format.
The colour themes in assets/vhs-themes.json are taken from the VHS project and are licensed under the MIT License. See licenses/VHS-MIT.txt for the full license text.
Some fonts are embedded inside the EVP binary. See licenses in license for the full license text.