Par Term Emu Core Rust

A comprehensive terminal emulator library written in Rust with Python bindings for Python 3.12+. Provides VT100/VT220/VT320/VT420/VT520 compatibility with PTY support, matching iTerm2's feature set.

What's New in 0.14.0

🎉 New Features

• Web Terminal Onscreen Keyboard: Mobile-friendly virtual keyboard for touch devices

  • Special keys missing from iOS/Android keyboards: Esc, Tab, arrow keys, Page Up/Down, Home, End, Insert, Delete
  • Function keys F1-F12 (toggleable), symbol keys (|, , `, ~, {, }, etc.)
  • Modifier keys (Ctrl, Alt, Shift) that combine with other keys
  • Quick Ctrl shortcuts: ^C, ^D, ^Z, ^L, ^A, ^E, ^K, ^U, ^W, ^R
  • Glass morphism design, haptic feedback, auto-shows on mobile

• OSC 9;4 Progress Bar Support (ConEmu/Windows Terminal style):

  • Terminal applications can report progress that can be displayed in tab bars, taskbars, or window titles
  • Five states: Hidden, Normal, Indeterminate, Warning, Error
  • Progress percentage (0-100) for applicable states
  • New ProgressState enum and ProgressBar class in Python
  • Terminal methods: progress_bar(), has_progress(), progress_value(), progress_state(), set_progress(), clear_progress()

from par_term_emu_core_rust import Terminal, ProgressState

term = Terminal(80, 24)

# Receive progress from application
term.process(b"\x1b]9;4;1;50\x1b\\")  # Set progress to 50%

# Check progress state
if term.has_progress():
    pb = term.progress_bar()
    print(f"Progress: {pb.progress}%, State: {pb.state}")

# Programmatic control
term.set_progress(ProgressState.Warning, 75)  # Set warning at 75%
term.clear_progress()  # Hide progress bar

See CHANGELOG.md for complete version history.

What's New in 0.13.0

🎉 New Features

• Streaming Server Enhancements:

  • --size CLI option for specifying terminal size in COLSxROWS format (e.g., --size 120x40 or -s 120x40)
  • --command / -c CLI option to execute a command after shell startup (with 1 second delay for prompt settling)
  • initial_cols and initial_rows configuration options in StreamingConfig for both Rust and Python APIs

• Python Bindings Enhancements:

  • New MouseEncoding enum for mouse event encoding control (Default, Utf8, Sgr, Urxvt)
  • Direct screen buffer control: use_alt_screen(), use_primary_screen()
  • Mouse encoding control: mouse_encoding(), set_mouse_encoding()
  • Mode setters: set_focus_tracking(), set_bracketed_paste(), set_title()
  • Bold brightening control: bold_brightening(), set_bold_brightening()
  • Color getters for all theme colors (link, bold, cursor guide, badge, match, selection)

What's New in 0.12.0

🐛 Bug Fixes

• Terminal Reflow Improvements: Multiple fixes to scrollback and grid reflow behavior during resize

What's New in 0.11.0

🎉 New Features

• Full Terminal Reflow on Width Resize: Both scrollback AND visible screen content now reflow when terminal width changes
  • Previously, width changes cleared scrollback and clipped visible content
  • Now implements intelligent reflow similar to xterm and iTerm2:
    • Scrollback: Preserves all history with proper line wrapping/unwrapping
    • Visible Screen: Content wraps instead of being clipped when narrowing
    • Width increase: Unwraps soft-wrapped lines into longer lines
    • Width decrease: Re-wraps lines that no longer fit
  • Preserves all cell attributes (colors, bold, italic, etc.)
  • Handles wide characters (CJK, emoji) correctly at line boundaries
  • Significant UX improvement for terminal resize operations

What's New in 0.10.0

🎉 New Features

• Emoji Sequence Preservation: Complete support for complex emoji sequences and grapheme clusters

  • ⚠️ vs ⚠ - Variation selectors (emoji vs text style)
  • 👋🏽 - Skin tone modifiers (Fitzpatrick scale)
  • 👨‍👩‍👧‍👦 - ZWJ sequences (family emoji)
  • 🇺🇸 🇬🇧 - Regional indicator flags
  • é - Combining diacritics and marks
  • New grapheme module for Unicode cluster detection
  • Enhanced Python bindings export full grapheme clusters

• Web Terminal Frontend: Modern Next.js-based web interface

  • Built with Next.js, TypeScript, and Tailwind CSS v4
  • Theme support with configurable color palettes
  • Nerd Font support for file/folder icons
  • New Makefile targets for web frontend development

• Terminal Sequence Support:

  • CSI 3J - Clear scrollback buffer command
  • Improved cursor positioning for snapshot exports

🐛 Bug Fixes

• Graphics now properly preserved when scrolling into scrollback buffer
• Sixel content saved to scrollback during large scrolling operations
• Kitty Graphics Protocol animation parsing fixes (base64 encoding, frame actions)

⚠️ Breaking Changes (Rust API only)

• Cell struct no longer implements Copy (now Clone only)
  • Required for variable-length grapheme cluster storage
  • All cell copy operations now require explicit .clone() calls
  • Python bindings are unaffected - no changes needed in Python code
  • Performance impact is minimal due to efficient cloning

What's New in 0.9.1

• Theme Rendering Fix: Fixed theme color palette application in Python bindings

What's New in 0.9.0

• Graphics Protocol Support: Comprehensive multi-protocol graphics implementation

  • iTerm2 Inline Images (OSC 1337): PNG, JPEG, GIF support with base64 encoding
  • Kitty Graphics Protocol (APC G): Advanced image placement with reuse and animations
  • Sixel Graphics: Enhanced with unique IDs and configurable cell dimensions
  • Unified GraphicsStore with scrollback support and memory limits
  • Animation support with frame composition and timing control
  • Graphics dropped event tracking for resource management

• Pre-built Streaming Server Binaries: Download ready-to-run binaries from GitHub Releases

  • Linux (x86_64, ARM64), macOS (Intel, Apple Silicon), Windows (x86_64)
  • No compilation needed - just download and run
  • Includes separate web frontend package (tar.gz/zip) for serving the terminal interface
  • Published to crates.io for Rust developers: cargo install par-term-emu-core-rust --features streaming

See CHANGELOG.md for complete version history.

Features

Core Terminal Emulation

• VT100/VT220/VT320/VT420/VT520 Support - Comprehensive terminal emulation matching iTerm2
• Rich Color Support - 16 ANSI colors, 256-color palette, 24-bit RGB (true color)
• Text Attributes - Bold, italic, underline (5 styles), strikethrough, blink, reverse, dim, hidden
• Advanced Cursor Control - Full VT cursor movement and positioning
• Line/Character Editing - VT220 insert/delete operations
• Rectangle Operations - VT420 fill/copy/erase/modify rectangular regions (DECFRA, DECCRA, etc.)
• Scrolling Regions - DECSTBM for restricted scrolling areas
• Tab Stops - Configurable tab stops (HTS, TBC, CHT, CBT)
• Unicode Support - Full Unicode including complex emoji sequences and grapheme clusters
  • Variation selectors (emoji vs text presentation)
  • Skin tone modifiers (Fitzpatrick scale U+1F3FB-U+1F3FF)
  • Zero Width Joiner (ZWJ) sequences for multi-emoji glyphs
  • Regional indicators for flag emoji
  • Combining characters and diacritical marks

Modern Features

• Alternate Screen Buffer - Full support with automatic cleanup
• Mouse Support - Multiple tracking modes and encodings (X10, Normal, Button, Any, SGR, URXVT)
• Bracketed Paste Mode - Safe paste handling
• Focus Tracking - Focus in/out events
• OSC 8 Hyperlinks - Clickable URLs in terminal (full TUI support)
• OSC 52 Clipboard - Copy/paste over SSH without X11
• OSC 9/777 Notifications - Desktop-style alerts and notifications
• Shell Integration - OSC 133 (iTerm2/VSCode compatible)
• Kitty Keyboard Protocol - Progressive keyboard enhancement with auto-reset on alternate screen exit
• Synchronized Updates (DEC 2026) - Flicker-free rendering
• Tmux Control Protocol - Control mode integration support

Graphics Support

• Sixel Graphics - DEC VT340 compatible bitmap graphics with half-block rendering
• iTerm2 Inline Images - OSC 1337 protocol for PNG, JPEG, GIF images
• Kitty Graphics Protocol - APC G protocol with image reuse, animations, and advanced placement
• Unicode Placeholders - Virtual placements insert U+10EEEE characters for inline image display
• Unified Graphics Store - Protocol-agnostic storage with scrollback support
• Animation Support - Frame-based animations with timing and composition control
• Resource Management - Configurable memory limits and graphics dropped tracking

PTY Support

• Interactive Shell Sessions - Spawn and control shell processes
• Bidirectional I/O - Send input and receive output
• Process Management - Start, stop, and monitor child processes
• Dynamic Resizing - Resize with SIGWINCH signal
• Environment Control - Custom environment variables and working directory
• Event Loop Integration - Non-blocking update detection
• Cross-Platform - Linux, macOS, and Windows via portable-pty

Terminal Streaming (WebSocket)

• Standalone Server - Pure Rust streaming server binary (no Python required)
• Real-time Streaming - Sub-100ms latency terminal streaming over WebSocket
• Multiple Clients - Support for concurrent viewers per session
• Authentication - Optional API key authentication (header or URL param)
• Configurable Themes - Multiple built-in color themes (iTerm2, Monokai, Dracula, Solarized)
• Auto-resize - Client-initiated terminal resizing with SIGWINCH support
• Browser Compatible - Works with any WebSocket client (xterm.js recommended)
• Modern Web Frontend - Next.js/React application with Tailwind CSS v4 and xterm.js

Screenshots and Export

• Multiple Formats - PNG, JPEG, BMP, SVG (vector), HTML
• Embedded Font - JetBrains Mono bundled - no installation required
• Programming Ligatures - =>, !=, >=, and other code ligatures
• True Font Rendering - High-quality antialiasing for raster formats
• Color Emoji Support - Full emoji rendering with automatic font fallback
• Session Recording - Record/replay sessions (asciicast v2, JSON)
• Export Functions - Plain text, ANSI styled, HTML export

Macro Recording and Playback

• YAML Format - Human-readable macro storage format
• Friendly Key Names - Intuitive key combinations (ctrl+shift+s, enter, f1, etc.)
• Keyboard Events - Record and replay keyboard input with precise timing
• Delays - Control timing between events
• Screenshot Triggers - Trigger screenshots during playback
• Playback Controls - Play, pause, resume, stop, and speed control
• Macro Library - Store and manage multiple macros
• Recording Conversion - Convert terminal recording sessions to macros

Utility Functions

• Text Extraction - Smart word/URL detection, selection boundaries, bracket matching
• Content Search - Find text with case-sensitive/insensitive matching
• Buffer Statistics - Memory usage, cell counts, graphics count and memory tracking
• Color Utilities - 18+ color manipulation functions (iTerm2-compatible)
  • NTSC brightness, contrast adjustment, WCAG accessibility checks
  • Color space conversions (RGB, HSL, Hex, ANSI 256)
  • Saturation/hue adjustment, color mixing

Documentation

• API Reference - Complete Python API documentation
• VT Sequences - Comprehensive ANSI/VT sequence reference
• Advanced Features - Detailed feature guides
• Architecture - Internal architecture details
• Security - PTY security best practices
• Building - Build instructions and requirements
• Configuration Reference - Configuration options
• Cross-Platform Notes - Platform-specific information
• VT Technical Reference - Detailed VT compatibility and implementation
• Fonts - Font configuration and rendering
• Macros - Macro recording and playback system
• Streaming - WebSocket terminal streaming
• Rust Usage - Using the library in pure Rust projects
• Graphics Testing - Testing graphics protocol implementations

Installation

From PyPI

uv add par-term-emu-core-rust
# or
pip install par-term-emu-core-rust

From Source

Requires Rust 1.75+ and Python 3.12+:

# Install maturin (build tool)
uv tool install maturin

# Build and install
maturin develop --release

Building a Wheel

maturin build --release
uv add --find-links target/wheels par-term-emu-core-rust
# or
pip install target/wheels/par_term_emu_core_rust-*.whl

Using as a Rust Library

The library can be used in pure Rust projects without Python. Choose your feature combination:

Use Case	Cargo.toml	What's Included
Rust Only	par-term-emu-core-rust = { version = "0.10", default-features = false }	Terminal, PTY, Macros
Rust + Streaming	par-term-emu-core-rust = { version = "0.10", default-features = false, features = ["streaming"] }	+ WebSocket/HTTP server
Python Only	par-term-emu-core-rust = "0.10"	+ Python bindings
Everything	par-term-emu-core-rust = { version = "0.10", features = ["full"] }	All features

Download pre-built streaming server (recommended):

Pre-built binaries and web frontend packages are available from GitHub Releases:

# Download binary (Linux example)
wget https://github.com/paulrobello/par-term-emu-core-rust/releases/latest/download/par-term-streamer-linux-x86_64
chmod +x par-term-streamer-linux-x86_64

# Download web frontend
wget https://github.com/paulrobello/par-term-emu-core-rust/releases/latest/download/par-term-web-frontend-v0.10.0.tar.gz
tar -xzf par-term-web-frontend-v0.10.0.tar.gz -C ./web_term

# Run
./par-term-streamer-linux-x86_64 --web-root ./web_term

Available binaries: Linux (x86_64, ARM64), macOS (Intel, Apple Silicon), Windows (x86_64)

Or install from crates.io:

cargo install par-term-emu-core-rust --features streaming

Or build from source:

cargo build --bin par-term-streamer --no-default-features --features streaming --release
./target/release/par-term-streamer --help

See docs/RUST_USAGE.md for detailed Rust API documentation and examples.

Optional Components

Terminfo Installation

For optimal terminal compatibility, install the par-term terminfo definition:

# Install for current user
./terminfo/install.sh

# Or install system-wide
sudo ./terminfo/install.sh --system

# Then use
export TERM=par-term
export COLORTERM=truecolor

See terminfo/README.md for details.

Shell Integration

Enhances terminal with semantic prompt markers, command status tracking, and smart selection:

cd shell_integration
./install.sh  # Auto-detects bash/zsh/fish

See shell_integration/README.md for details.

Quick Start

Basic Terminal Emulation

from par_term_emu_core_rust import Terminal

# Create terminal
term = Terminal(80, 24)

# Process ANSI sequences
term.process_str("Hello, \x1b[31mWorld\x1b[0m!\n")
term.process_str("\x1b[1;32mBold green text\x1b[0m\n")

# Get content and cursor position
print(term.content())
col, row = term.cursor_position()
print(f"Cursor at: ({col}, {row})")

PTY (Interactive Shell)

from par_term_emu_core_rust import PtyTerminal
import time

# Create PTY terminal and spawn shell
with PtyTerminal(80, 24) as term:
    term.spawn_shell()

    # Send commands
    term.write_str("echo 'Hello from shell!'\n")
    time.sleep(0.2)

    # Get output
    print(term.content())

    # Resize terminal
    term.resize(100, 30)

    # Exit shell
    term.write_str("exit\n")
# Automatic cleanup

Screenshots

term = Terminal(80, 24)
term.process_str("\x1b[1;31mHello, World!\x1b[0m\n")

# Save screenshot
term.screenshot_to_file("output.png")
term.screenshot_to_file("output.svg", format="svg")  # Vector graphics!
term.screenshot_to_file("output.html", format="html")  # Styled HTML

# Custom configuration
term.screenshot_to_file(
    "output.png",
    font_size=16.0,
    padding=20,
    include_scrollback=True,
    minimum_contrast=0.5  # iTerm2-compatible contrast adjustment
)

Color Utilities

from par_term_emu_core_rust import (
    perceived_brightness_rgb, adjust_contrast_rgb,
    contrast_ratio, meets_wcag_aa,
    rgb_to_hex, hex_to_rgb, mix_colors
)

# iTerm2-compatible contrast adjustment
adjusted = adjust_contrast_rgb((64, 64, 64), (0, 0, 0), 0.5)

# WCAG accessibility checks
ratio = contrast_ratio((0, 0, 0), (255, 255, 255))
print(f"Contrast ratio: {ratio:.1f}:1")
print(f"Meets WCAG AA: {meets_wcag_aa((0, 0, 0), (255, 255, 255))}")

# Color conversions
hex_color = rgb_to_hex((255, 128, 64))  # "#FF8040"
rgb = hex_to_rgb("#FF8040")  # (255, 128, 64)
mixed = mix_colors((255, 0, 0), (0, 0, 255), 0.5)  # Purple

Macro Recording and Playback

from par_term_emu_core_rust import Macro, PtyTerminal
import time

# Create a macro manually
macro = Macro("git_status")
macro.set_description("Check git status and show branch")
macro.add_key("g")
macro.add_key("i")
macro.add_key("t")
macro.add_key("space")
macro.add_key("s")
macro.add_key("t")
macro.add_key("a")
macro.add_key("t")
macro.add_key("u")
macro.add_key("s")
macro.add_key("enter")
macro.add_delay(500)  # Wait 500ms
macro.add_screenshot("git_status.png")  # Trigger screenshot

# Save to YAML
macro.save_yaml("git_status.yaml")

# Load and play back
term = PtyTerminal(80, 24)
term.spawn_shell()

# Load macro from file
loaded_macro = Macro.load_yaml("git_status.yaml")
term.load_macro("git_check", loaded_macro)

# Play the macro
term.play_macro("git_check", speed=1.0)  # Normal speed

# Tick to execute macro events
while term.is_macro_playing():
    if term.tick_macro():  # Returns True if event was processed
        time.sleep(0.01)  # Small delay for visual effect

    # Check for screenshot triggers
    triggers = term.get_macro_screenshot_triggers()
    for label in triggers:
        term.screenshot_to_file(label)

# Convert a recording to a macro
term.start_recording("test session")
term.write_str("ls -la\n")
time.sleep(0.5)
session = term.stop_recording()

# Convert and save
macro = term.recording_to_macro(session, "ls_command")
macro.save_yaml("ls_command.yaml")

Examples

See the examples/ directory for comprehensive examples:

Basic Examples

• basic_usage_improved.py - Enhanced basic usage
• colors_demo.py - Color support
• cursor_movement.py - Cursor control
• text_attributes.py - Text styling
• unicode_emoji.py - Unicode/emoji support
• scrollback_demo.py - Scrollback buffer usage

Advanced Features

• alt_screen.py - Alternate screen buffer
• mouse_tracking.py - Mouse events
• bracketed_paste.py - Bracketed paste
• synchronized_updates.py - Flicker-free rendering
• shell_integration.py - OSC 133 integration
• test_osc52_clipboard.py - SSH clipboard
• test_kitty_keyboard.py - Kitty keyboard protocol
• hyperlink_demo.py - Clickable URLs
• notifications.py - Desktop notifications
• rectangle_operations.py - VT420 rectangle ops

Graphics and Export

• display_image_sixel.py - Sixel graphics
• test_sixel_simple.py - Simple sixel examples
• test_sixel_display.py - Advanced sixel display
• screenshot_demo.py - Screenshot features
• feature_showcase.py - Comprehensive TUI showcase

PTY Examples

• pty_basic.py - Basic PTY usage
• pty_shell.py - Interactive shells
• pty_resize.py - Dynamic resizing
• pty_event_loop.py - Event loop integration
• pty_mouse_events.py - Mouse in PTY
• pty_custom_env.py - Custom environment variables
• pty_multiple.py - Multiple PTY sessions
• pty_with_par_term.py - Integration with par-term

Terminal Streaming

• streaming_demo.py - Python WebSocket streaming server
• streaming_client.html - Browser-based terminal client

Macros and Automation

• demo.yaml - Example macro definition

Standalone Rust Server:

# Build and run (default: ws://127.0.0.1:8080)
make streamer-run

# Run with authentication
make streamer-run-auth

# Or use cargo directly
cargo build --bin par-term-streamer --no-default-features --features streaming --release
./target/release/par-term-streamer --port 8080 --theme dracula

# With authentication
./target/release/par-term-streamer --api-key my-secret --theme monokai

# Install globally
make streamer-install
par-term-streamer --help

Available Themes: iterm2-dark, monokai, dracula, solarized-dark

Web Terminal Frontend

Using Pre-built Package (Recommended):

Download the pre-built static web frontend from GitHub Releases:

# Download and extract
wget https://github.com/paulrobello/par-term-emu-core-rust/releases/latest/download/par-term-web-frontend-v0.10.0.tar.gz
tar -xzf par-term-web-frontend-v0.10.0.tar.gz -C ./web_term

# Run streamer with web frontend
par-term-streamer --web-root ./web_term
# Open browser to http://localhost:8080

See web_term/README.md for detailed usage instructions.

Building from Source:

A modern Next.js-based web terminal frontend source is in web-terminal-frontend/:

cd web-terminal-frontend

# Install dependencies
npm install

# Development server (runs on port 8030)
npm run dev

# Build for production (outputs to out/)
npm run build

# Copy to web_term for serving
cp -r out/* ../web_term/

Features:

• Modern UI with Tailwind CSS v4
• xterm.js terminal emulator
• WebSocket connection to streaming server
• Theme selection and synchronization
• Responsive design
• Terminal resize support

See web-terminal-frontend/README.md for detailed setup and configuration.

TUI Demo Application

A full-featured TUI (Text User Interface) application is available in the sister project par-term-emu-tui-rust.

Installation: uv add par-term-emu-tui-rust or pip install par-term-emu-tui-rust

GitHub: https://github.com/paulrobello/par-term-emu-tui-rust

Technology

• Rust (1.75+) - Core library implementation
• Python (3.12+) - Python bindings
• PyO3 - Zero-cost Python/Rust bindings
• VTE - ANSI sequence parsing
• portable-pty - Cross-platform PTY support

Running Tests

# Run Rust tests
cargo test

# Run Python tests
uv sync  # Install dependencies including pytest
pytest tests/

Performance

• Zero-copy operations where possible
• Efficient grid representation
• Fast ANSI parsing with VTE crate
• Minimal Python/Rust boundary crossings

See docs/ARCHITECTURE.md for implementation details.

Security

When using PTY functionality, follow security best practices to prevent command injection and other vulnerabilities.

See docs/SECURITY.md for comprehensive security guidelines.

Contributing

Contributions are welcome! Please submit issues or pull requests on GitHub.

Development Setup

git clone https://github.com/paulrobello/par-term-emu-core-rust.git
cd par-term-emu-core-rust
make setup-venv  # Create virtual environment
make pre-commit-install  # Install pre-commit hooks (recommended)
make dev  # Build library
make checkall  # Run all quality checks

Code Quality

All contributions must pass:

• Rust formatting (cargo fmt)
• Rust linting (cargo clippy)
• Python formatting (make fmt-python)
• Python linting (make lint-python)
• Type checking (pyright)
• Tests (make test-python)

TIP: Use make pre-commit-install to automate all checks on every commit!

See CLAUDE.md for detailed development instructions.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Author

Paul Robello - probello@gmail.com

Links

• PyPI: https://pypi.org/project/par-term-emu-core-rust/
• Crates.io: https://crates.io/crates/par-term-emu-core-rust
• GitHub: https://github.com/paulrobello/par-term-emu-core-rust
• TUI Application: https://github.com/paulrobello/par-term-emu-tui-rust
• Documentation: See docs/ directory
• Examples: See examples/ directory