par-term-emu-core-rust 0.33.0

A comprehensive terminal emulator library in Rust with Python bindings - supports true color, alt screen, mouse reporting, bracketed paste, and full Unicode

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 0.33.0

Multi-Session Streaming Server

The streaming server now supports multiple concurrent terminal sessions. Each WebSocket client can connect to a named session, and new sessions are created on demand:

ws://host:port/ws?session=my-session     # Connect to (or create) a named session
ws://host:port/ws?preset=python           # Create a session using a shell preset
ws://host:port/ws                         # Connect to the default session

Key features:

• Session isolation: Each session has its own terminal, PTY, and broadcast channels
• Shell presets: Define named shell commands (--preset python=python3 --preset node=node)
• Idle timeout: Sessions with no clients are automatically reaped (default: 15 minutes)
• Client identity: Each client receives a unique client_id in the Connected handshake
• Read-only awareness: The readonly field in Connected tells clients their permission level

Default limits:

• Max concurrent sessions: 10
• Idle session timeout: 900 seconds (15 minutes)
• Max clients per server: 100 (unchanged)

New Streaming Events: Mode, Graphics, and Hyperlink

Three new event types allow streaming clients to react to terminal state changes:

• ModeChanged: Fires when terminal modes toggle (e.g., cursor visibility, mouse tracking, bracketed paste). Subscribe with "mode".
• GraphicsAdded: Fires when images are rendered via Sixel, iTerm2, or Kitty protocols. Includes row position and format. Subscribe with "graphics".
• HyperlinkAdded: Fires when OSC 8 hyperlinks are added. Includes URL, row, column, and optional link ID. Subscribe with "hyperlink".

Breaking: StreamingConfig has new required fields (max_sessions, session_idle_timeout, presets). ServerMessage::Connected now includes client_id and readonly fields.

What's New in 0.32.0

Coprocess Restart Policies & Stderr Capture

Coprocesses now support automatic restart when they exit, and stderr is captured separately:

from par_term_emu_core_rust import PtyTerminal, CoprocessConfig

with PtyTerminal(80, 24) as term:
    term.spawn_shell()

    # Start a coprocess that auto-restarts on failure with a 1-second delay
    config = CoprocessConfig(
        "my-watcher",
        restart_policy="on_failure",
        restart_delay_ms=1000,
    )
    cid = term.start_coprocess(config)

    # Read stderr separately from stdout
    errors = term.read_coprocess_errors(cid)
    output = term.read_from_coprocess(cid)

Restart Policies: "never" (default), "always", "on_failure" (non-zero exit only)

Trigger Notify & MarkLine as Frontend Events

Notify and MarkLine trigger actions now emit ActionResult events (via poll_action_results()) instead of directly modifying internal state. This gives frontends full control over how notifications and line marks are displayed. MarkLine also supports an optional color parameter:

mark = TriggerAction("mark_line", {"label": "Error", "color": "255,0,0"})

Breaking: If you relied on Notify triggers adding to the notification queue or MarkLine triggers adding bookmarks directly, you must now handle these via poll_action_results().

What's New in 0.31.1

Trigger Column Mapping Fix

TriggerMatch.col and TriggerMatch.end_col now correctly report grid column positions for text containing wide characters (CJK, emoji) and multi-byte UTF-8 characters. Previously, regex byte offsets were used directly, producing incorrect column values for non-ASCII text. Trigger highlights now correctly overlay the matched text even when wide or combining characters appear in the same row.

What's New in 0.31.0

Triggers & Automation

Register regex patterns to automatically match terminal output and execute actions — highlight matches, send notifications, set bookmarks, update session variables, or emit events for frontend handling:

from par_term_emu_core_rust import Terminal, TriggerAction

term = Terminal(80, 24)

# Highlight errors in red
highlight = TriggerAction("highlight", {"bg_r": "255", "bg_g": "0", "bg_b": "0"})
term.add_trigger("errors", r"ERROR:\s+(\S+)", [highlight])

# Set a session variable from matched output
set_var = TriggerAction("set_variable", {"name": "last_status", "value": "$1"})
term.add_trigger("status", r"STATUS: (\w+)", [set_var])

# Process terminal output and scan for matches
term.process_str("ERROR: diskfull\nSTATUS: RUNNING\n")
term.process_trigger_scans()

# Poll results
matches = term.poll_trigger_matches()  # TriggerMatch objects with captures
highlights = term.get_trigger_highlights()  # Active highlight overlays

Trigger Actions: highlight, notify, mark_line, set_variable, run_command, play_sound, send_text, stop

Features:

• RegexSet-based multi-pattern matching for efficient scanning
• Capture group substitution ($1, $2) in action parameters
• Highlight overlays with optional time-based expiry
• Automatic scanning in PTY mode; manual process_trigger_scans() for non-PTY

Coprocess Management

Run external processes alongside terminal sessions with automatic output piping:

from par_term_emu_core_rust import PtyTerminal, CoprocessConfig

with PtyTerminal(80, 24) as term:
    term.spawn_shell()

    # Start a coprocess that receives terminal output
    config = CoprocessConfig("grep", args=["ERROR"], copy_terminal_output=True)
    cid = term.start_coprocess(config)

    # Read coprocess output
    lines = term.read_from_coprocess(cid)

    # Check status and stop
    term.coprocess_status(cid)  # True if running
    term.stop_coprocess(cid)

New Python Classes: Trigger, TriggerAction, TriggerMatch, CoprocessConfig

What's New in 0.30.0

⌨️ modifyOtherKeys Protocol Support

XTerm extension for enhanced keyboard input reporting, enabling applications to receive modifier keys with regular characters:

from par_term_emu_core_rust import Terminal

term = Terminal(80, 24)

# Enable modifyOtherKeys mode via escape sequence
term.process(b"\x1b[>4;2m")  # Mode 2: report all keys with modifiers
print(f"Mode: {term.modify_other_keys_mode()}")  # Output: 2

# Or set directly
term.set_modify_other_keys_mode(1)  # Mode 1: special keys only

# Query mode (response in drain_responses())
term.process(b"\x1b[?4m")
response = term.drain_responses()  # Returns b"\x1b[>4;1m"

Modes:

• 0 - Disabled (default)
• 1 - Report modifiers for special keys only
• 2 - Report modifiers for all keys

New Methods:

• modify_other_keys_mode() - Get current mode
• set_modify_other_keys_mode(mode) - Set mode directly (values > 2 clamped to 2)

Sequences:

• CSI > 4 ; mode m - Set mode
• CSI ? 4 m - Query mode (response: CSI > 4 ; mode m)

Note: Mode resets to 0 on terminal reset and when exiting alternate screen.

🎨 Faint Text Alpha Control

Configurable alpha multiplier for SGR 2 (dim/faint) text, allowing fine-grained control over how dim text is rendered:

from par_term_emu_core_rust import Terminal

term = Terminal(80, 24)

# Get current faint text alpha (default: 0.5 = 50% dimming)
print(f"Alpha: {term.faint_text_alpha()}")  # Output: 0.5

# Set faint text to be more transparent (more dimmed)
term.set_faint_text_alpha(0.3)  # 30% opacity

# Set faint text to be less transparent (less dimmed)
term.set_faint_text_alpha(0.7)  # 70% opacity

# Values are clamped to 0.0-1.0 range
term.set_faint_text_alpha(1.5)  # Clamped to 1.0
term.set_faint_text_alpha(-0.5)  # Clamped to 0.0

New Methods:

• faint_text_alpha() - Get current alpha multiplier (0.0-1.0)
• set_faint_text_alpha(alpha) - Set alpha multiplier (clamped to valid range)

Usage: This setting is used by the screenshot renderer and can be queried by frontends for consistent rendering of dim text (SGR 2).

What's New in 0.28.0

🏷️ Badge Format Support (OSC 1337 SetBadgeFormat)

iTerm2-style badge support for terminal overlays with variable interpolation:

from par_term_emu_core_rust import Terminal

term = Terminal(80, 24)

# Set badge format with variables
term.set_badge_format(r"\(username)@\(hostname)")

# Set session variables
term.set_badge_session_variable("username", "alice")
term.set_badge_session_variable("hostname", "server1")

# Evaluate badge - returns "alice@server1"
badge = term.evaluate_badge()
print(f"Badge: {badge}")

# Get all session variables
vars = term.get_badge_session_variables()
print(f"Columns: {vars['columns']}, Rows: {vars['rows']}")

New Methods:

• badge_format() - Get current badge format template
• set_badge_format(format) - Set badge format with \(variable) placeholders
• clear_badge_format() - Clear badge format
• evaluate_badge() - Evaluate badge with session variables
• get_badge_session_variable(name) - Get a session variable value
• set_badge_session_variable(name, value) - Set a custom session variable
• get_badge_session_variables() - Get all session variables as a dictionary

Built-in Variables: hostname, username, path, job, last_command, profile_name, tty, columns, rows, bell_count, selection, tmux_pane_title, session_name, title

Security: Badge formats are validated to reject shell injection patterns (backticks, $(), pipes, etc.)

🔧 Tmux Control Mode Fixes

• Fixed CRLF line ending handling (strips \r from \r\n line endings)
• Fixed %output notifications to preserve trailing spaces
• Fixed OSC 133 exit code parsing from OSC 133 ; D ; <exit_code> ST

What's New in 0.27.0

🔄 Tmux Control Mode Auto-Detection

Automatic detection and switching to tmux control mode to handle race conditions:

from par_term_emu_core_rust import Terminal

term = Terminal(80, 24)

# Enable auto-detection before starting tmux
# Parser will automatically switch to control mode when %begin is seen
term.set_tmux_auto_detect(True)

# Or just call set_tmux_control_mode(True) which enables auto-detect automatically
term.set_tmux_control_mode(True)

# Process tmux output - auto-detects %begin and switches modes
term.process_str("$ tmux -CC\n%begin 1234567890 1\n%output %1 Hello\n")

# Check modes
print(f"Control mode: {term.is_tmux_control_mode()}")
print(f"Auto-detect: {term.is_tmux_auto_detect()}")

New Methods:

• set_tmux_auto_detect(enabled) - Enable/disable auto-detection of tmux control mode
• is_tmux_auto_detect() - Check if auto-detection is enabled

Behavior:

• When %begin notification is detected, parser automatically switches to control mode
• Data before %begin is returned as TerminalOutput notification for normal display
• Calling set_tmux_control_mode(True) now also enables auto-detect

What's New in 0.26.0

🎬 Session Recording Enhancements

Full Python API for session recording with event iteration and environment capture:

from par_term_emu_core_rust import Terminal, RecordingEvent, RecordingSession

term = Terminal(80, 24)

# Start recording
term.start_recording("demo session")
term.process_str("echo hello\n")
term.record_marker("checkpoint")
session = term.stop_recording()

# Access session metadata
print(f"Duration: {session.get_duration_seconds()}s")
print(f"Size: {session.get_size()}")
print(f"Environment: {session.env}")

# Iterate over recorded events
for event in session.events:
    print(f"{event.event_type} at {event.timestamp}ms: {event.get_data_str()}")

New Exports:

• RecordingEvent and RecordingSession now directly importable from the module

New RecordingSession Properties:

• session.events - List of RecordingEvent objects
• session.env - Dict of captured environment variables

New PtyTerminal Methods:

• record_output(), record_input(), record_resize(), record_marker(), get_recording_session()

What's New in 0.25.0

🌐 Configurable Unicode Width

Full control over character width calculations for proper terminal alignment in CJK and mixed-script environments:

from par_term_emu_core_rust import (
    Terminal, WidthConfig, UnicodeVersion, AmbiguousWidth,
    char_width, str_width, is_east_asian_ambiguous
)

# Configure terminal for CJK environment (Greek/Cyrillic = 2 cells)
term = Terminal(80, 24)
term.set_width_config(WidthConfig.cjk())

# Or configure individually
term.set_ambiguous_width(AmbiguousWidth.Wide)
term.set_unicode_version(UnicodeVersion.Auto)

# Standalone width functions
print(char_width("日"))  # 2 - CJK character
print(char_width("α", WidthConfig.cjk()))  # 2 - Greek with CJK config
print(str_width("Hello日本"))  # 9 - mixed text
print(is_east_asian_ambiguous("α"))  # True - Greek is ambiguous

New Types:

• UnicodeVersion: Unicode9-Unicode16, Auto
• AmbiguousWidth: Narrow (1 cell), Wide (2 cells)
• WidthConfig: Combines both with .cjk() and .western() presets

New Functions:

• char_width(c, config?) / str_width(s, config?) - configurable width
• char_width_cjk(c) / str_width_cjk(s) - CJK convenience functions
• is_east_asian_ambiguous(c) - check if character is ambiguous

What's New in 0.23.0

📨 Configurable ENQ Answerback

• Added an optional answerback string that the terminal returns when receiving ENQ (0x05)
• Disabled by default for security; set a custom value via Rust API or Python bindings
• Responses are buffered in the existing response buffer and drained with drain_responses()
• Python bindings now expose answerback_string() and set_answerback_string()

What's New in 0.22.1

🐛 Search Unicode Bug Fix

Fixed search() and search_scrollback() returning byte offsets instead of character offsets for text containing multi-byte Unicode characters (CJK, emoji, etc.):

• SearchMatch.col now correctly returns the character column position
• SearchMatch.length now correctly returns the character count
• Example: Searching for "World" in "こんにちは World" now returns col=6 (correct) instead of col=16 (byte offset)

What's New in 0.22.0

🏳️ Regional Indicator Flag Emoji Support

Proper grapheme cluster handling for flag emoji like 🇺🇸, 🇬🇧, 🇯🇵:

• Flag emoji are now correctly combined into single wide (2-cell) graphemes
• Two regional indicator codepoints are combined with the first as the base character and the second in the combining vector
• Cursor correctly advances by 2 cells after writing a flag
• Added unicode-segmentation crate dependency for grapheme cluster support
• Comprehensive test suite for flag emoji

What's New in 0.21.0

🚀 parking_lot Migration

The entire library has been migrated from std::sync::Mutex to parking_lot::Mutex.

• Improved Reliability: Eliminated "Mutex Poisoning". A panic in one thread no longer renders the terminal state permanently inaccessible to other threads.
• Better Performance: Faster lock/unlock operations and significantly smaller memory footprint for locks.
• Ergonomic API: Lock acquisition no longer requires .unwrap(), making the code cleaner and more robust.

What's New in 0.20.1

🔧 Safe Environment Variable API

Added new methods to pass environment variables and working directory directly to spawned processes without modifying the global environment of the parent process.

• Rust: spawn_shell_with_env(env, cwd), spawn_with_env(command, args, env, cwd)
• Python: spawn_shell(env=None, cwd=None) - now supports optional environment dictionary and working directory path.
• Thread Safety: Eliminates the need for unsafe { std::env::set_var() } in multi-threaded applications like those using Tokio.

What's New in 0.20.0

🎨 External UI Theme

The web frontend UI chrome can now be customized after static build without rebuilding:

/* Edit web_term/theme.css */
:root {
  --terminal-bg: #0a0a0a;      /* Main background */
  --terminal-surface: #1a1a1a; /* Status bar, cards */
  --terminal-border: #2a2a2a;  /* Borders */
  --terminal-accent: #3a3a3a;  /* Scrollbar, accents */
  --terminal-text: #e0e0e0;    /* Primary text */
}

• Edit colors and refresh the page - no rebuild required
• Terminal emulator colors (ANSI palette) still controlled by server --theme option
• See docs/STREAMING.md for details

🐛 Bug Fixes

• Web Terminal On-Screen Keyboard: Fixed native device keyboard appearing when tapping on-screen keyboard buttons on mobile devices
  • The on-screen keyboard now properly prevents xterm's internal textarea from gaining focus
  • Tapping virtual keys no longer triggers the device's native keyboard

What's New in 0.19.5

🐛 Bug Fixes

• Streaming Server Shell Restart Input: Fixed WebSocket client connections not receiving input after shell restart
  • PTY writer was captured once at connection time, becoming stale after shell restart
  • Client keyboard input now properly reaches the shell after any restart

What's New in 0.19.4

🔧 Python SDK Sync

• Python SDK aligned with Rust SDK: All streaming features now available in Python bindings
  • StreamingConfig.enable_http / web_root - HTTP server configuration (getter/setter)
  • StreamingServer.max_clients() - Query maximum allowed clients
  • StreamingServer.create_theme_info() - Create theme dictionaries for protocol
  • encode_server_message("pong") - Pong message encoding support
  • encode_server_message("connected", theme=...) - Theme support in connected messages

from par_term_emu_core_rust import StreamingConfig, StreamingServer, encode_server_message

# Configure HTTP serving
config = StreamingConfig(enable_http=True, web_root="/var/www/terminal")

# Create theme for connected message
theme = StreamingServer.create_theme_info(
    name="my-theme",
    background=(0, 0, 0),
    foreground=(255, 255, 255),
    normal=[(0,0,0), (255,0,0), (0,255,0), (255,255,0), (0,0,255), (255,0,255), (0,255,255), (200,200,200)],
    bright=[(128,128,128), (255,128,128), (128,255,128), (255,255,128), (128,128,255), (255,128,255), (128,255,255), (255,255,255)]
)

# Encode messages
pong = encode_server_message("pong")
connected = encode_server_message("connected", cols=80, rows=24, session_id="abc", theme=theme)

What's New in 0.19.2

🐛 Bug Fixes

• Streaming Server Hang on Shell Exit: Fixed server hanging indefinitely when the shell exits
  • Added shutdown signal mechanism to gracefully terminate the broadcaster loop
  • Prevents blocking indefinitely when shell exits in some conditions

What's New in 0.19.1

🐛 Bug Fixes

• Streaming Server Ping/Pong: Fixed application-level ping/pong handling
  • Server was sending WebSocket-level pong frames instead of protobuf Pong messages
  • Frontend heartbeat mechanism now properly receives pong responses
  • Fixes stale connection detection that was failing due to missing pong responses

What's New in 0.19.0

🎉 New Features

• Automatic Shell Restart: Streaming server now automatically restarts the shell when it exits

  • Default behavior: shell is restarted automatically when it exits
  • New --no-restart-shell CLI option to disable automatic restart
  • New PAR_TERM_NO_RESTART_SHELL environment variable support
  • When restart is disabled, server exits gracefully when the shell exits

• Header/Footer Toggle in On-Screen Keyboard: Layout toggle button in keyboard header

  • Show/hide header and footer directly from the on-screen keyboard
  • Blue indicator shows when header/footer is visible
  • Convenient for maximizing terminal space on mobile

• Font Size Controls in On-Screen Keyboard: Plus/minus buttons in keyboard header

  • Adjust font size (8-32px) without opening the header panel

🔧 Changes

• StreamingServer API: set_pty_writer now uses interior mutability for shell restart support
• UI Improvements: Font size controls moved to keyboard header; floating buttons repositioned side by side

What's New in 0.18.2

🎉 New Features

• Font Size Control: User-adjustable terminal font size in web frontend

  • Plus/minus buttons in header (8px to 32px range)
  • Persisted to localStorage across sessions

• Heartbeat/Ping Mechanism: Stale WebSocket connection detection

  • Sends ping every 25s, expects pong within 10s
  • Automatically closes and reconnects stale connections

🔒 Security Hardening

• Web Terminal Security Fixes: Comprehensive security audit remediation
  • Reverse-tabnabbing prevention: Terminal links now open with noopener,noreferrer
  • Zip bomb protection: Added decompression size limits (256KB compressed, 2MB decompressed)
  • Localhost probe fix: WebSocket preconnect hints gated to development mode only
  • Snapshot size guard: 1MB limit on screen snapshots to prevent UI freezes

🐛 Bug Fixes

• WebSocket URL Changes: Properly disconnects and reconnects when URL changes
• Invalid URL Handling: Displays friendly error instead of crashing
• Next.js Config: Merged duplicate config files into single file
• Toggle Button Overlap: Moved button left to avoid scrollbar overlap

What's New in 0.18.1

🐛 Bug Fixes

• Web Terminal On-Screen Keyboard: Fixed device virtual keyboard appearing when tapping on-screen keyboard buttons on mobile devices
  • Added tabIndex={-1} to all buttons to prevent focus acquisition that triggered device keyboard

What's New in 0.18.0

🎉 New Features

• Environment Variable Support: All CLI options now support environment variables with PAR_TERM_ prefix

  • Examples: PAR_TERM_HOST, PAR_TERM_PORT, PAR_TERM_THEME, PAR_TERM_HTTP_USER
  • Configuration via environment for containerized deployments

• HTTP Basic Authentication: New password protection for the web frontend

  • --http-user - Username for HTTP Basic Auth
  • --http-password - Clear text password
  • --http-password-hash - htpasswd format hash (bcrypt, apr1, SHA1, MD5 crypt)
  • --http-password-file - Read password from file (auto-detects hash vs clear text)

🧪 Test Coverage

• Comprehensive Streaming Test Suite: 94 new tests for streaming functionality
  • Protocol message constructors, theme info, HTTP Basic Auth configuration
  • Binary protocol encoding/decoding with compression
  • Event types, streaming errors, JSON serialization
  • Unicode content and ANSI escape sequence preservation

🔧 Improvements

• Python Bindings: Binary protocol functions now properly exported (encode_server_message, decode_server_message, encode_client_message, decode_client_message)

Usage Examples

# Environment variables
export PAR_TERM_HOST=0.0.0.0
export PAR_TERM_HTTP_USER=admin
export PAR_TERM_HTTP_PASSWORD=secret
par-term-streamer --enable-http

# CLI with htpasswd hash
par-term-streamer --enable-http --http-user admin --http-password-hash '$apr1$...'

What's New in 0.17.0

🎉 New Features

• Web Terminal Macro System: New macro tab in the on-screen keyboard for creating and playing terminal command macros

  • Create named macros with multi-line scripts (one command per line)
  • Quick select buttons to run macros with a single tap
  • Playback with 200ms delay before each Enter key for reliable command execution
  • Edit and delete existing macros via hover menu
  • Stop button to abort macro playback mid-execution
  • Macros persist to localStorage across sessions
  • Visual feedback during playback (pulsing animation, stop button)
  • Option to disable sending Enter after each line (for text insertion macros)
  • Template commands for advanced scripting: [[delay:N]], [[enter]], [[tab]], [[esc]], [[space]], [[ctrl+X]], [[shift+X]], [[ctrl+shift+X]], [[shift+tab]], [[shift+enter]]

• On-Screen Keyboard Enhancements:

  • Permanent symbols grid on the right side with all keyboard symbols (32 keys)
  • Added Space, Enter, http://, and https:// buttons to modifier row
  • Added tooltips to Ctrl shortcut buttons
  • Expanded symbol keys with full punctuation set

🔧 Improvements

• On-Screen Keyboard Layout: Reorganized for better usability with more compact vertical layout and persistent symbols grid

📦 Dependency Updates

• Web Frontend: Updated @types/node (25.0.1 → 25.0.2)

What's New in 0.16.3

🐛 Bug Fixes

• Web Terminal tmux/TUI Fix: Fixed control characters (^[[?1;2c^[[>0;276;0c) appearing when running tmux or other TUI applications in the web terminal. The issue was caused by xterm.js generating Device Attributes responses when the backend terminal emulator already handles these queries.

🚀 Performance Optimizations

• jemalloc Allocator: New optional jemalloc feature for 5-15% server throughput improvement (non-Windows only)
• TCP_NODELAY: Disabled Nagle's algorithm for lower keystroke latency (up to 40ms improvement)
• Output Batching: Time-based batching at 60fps reduces WebSocket overhead by 50-80% during burst output
• Compression Threshold: Lowered to 256 bytes to compress more typical terminal output
• WebSocket Preconnect: Reduces initial connection latency by 100-200ms
• Font Preloading: Eliminates layout shift and font flash

📦 Dependency Updates

• Web Frontend: Updated Next.js and type definitions
• Pre-commit Hooks: Updated ruff linter

What's New in 0.16.2

🔧 Compatibility Fix

• TERM Environment Variable: Changed default TERM from xterm-kitty to xterm-256color for better compatibility with systems lacking kitty terminfo

What's New in 0.16.0

🔒 TLS/SSL Support

• Secure WebSocket Connections for production deployments:
  • New CLI options: --tls-cert, --tls-key, --tls-pem
  • Supports separate cert/key files or combined PEM
  • Enables HTTPS and WSS (secure WebSocket)

# Using separate cert and key files
par-term-streamer --enable-http --tls-cert cert.pem --tls-key key.pem

# Using combined PEM file
par-term-streamer --enable-http --tls-pem combined.pem

🚀 Performance: Binary Protocol

• BREAKING: Protocol Buffers for WebSocket Streaming:
  • Replaced JSON with binary Protocol Buffers encoding
  • ~80% smaller messages for typical terminal output
  • Optional zlib compression for large payloads (screen snapshots)
  • Wire format: 1-byte header + protobuf payload

🐍 Python Bindings

• TLS Configuration: StreamingConfig methods for TLS setup
• Binary Protocol Functions: encode_server_message(), decode_server_message(), encode_client_message(), decode_client_message()

See CHANGELOG.md for complete version history.

What's New in 0.15.0

🎉 New Features

• Streaming Server CLI Enhancements:
  • --download-frontend option to download prebuilt web frontend from GitHub releases
  • --frontend-version option to specify version to download (default: "latest")
  • --use-tty-size option to use current terminal size from TTY
  • No longer requires Node.js/npm to use web frontend - can download prebuilt version

Quick Start

# Build the streaming server
make streamer-build-release

# Download prebuilt web frontend (no Node.js required!)
./target/release/par-term-streamer --download-frontend

# Run server with frontend
./target/release/par-term-streamer --enable-http

# Open browser to http://127.0.0.1:8099

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

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()
  • Faint text alpha control: faint_text_alpha(), set_faint_text_alpha()
  • 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

Environment Variables and Working Directory

Pass environment variables and working directory directly to spawn_shell() without modifying the parent process environment. This is safe for multi-threaded applications (e.g., Tokio):

from par_term_emu_core_rust import PtyTerminal

# Spawn with custom environment variables
with PtyTerminal(80, 24) as term:
    term.spawn_shell(env={"MY_VAR": "hello", "DEBUG": "1"})
    term.write_str("echo $MY_VAR\n")  # Outputs: hello

# Spawn with custom working directory
with PtyTerminal(80, 24) as term:
    term.spawn_shell(cwd="/tmp")
    term.write_str("pwd\n")  # Outputs: /tmp

# Combine both
with PtyTerminal(80, 24) as term:
    term.spawn_shell(env={"PROJECT": "myapp"}, cwd="/home/user/projects")

The spawn() method also accepts env and cwd parameters:

term.spawn("/bin/bash", ["-c", "echo $MY_VAR"], env={"MY_VAR": "test"}, cwd="/tmp")

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
• Customizable UI theme - Edit theme.css after build (no rebuild required)

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 - [e-mail]

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