feat(terminal): integrate ghostty-vt for terminal emulation

build.zig

@@ -609,7 +609,6 @@ fn configureObj(b: *Build, opts: *BunBuildOptions, obj: *Compile) void {
 
     obj.no_link_obj = opts.os != .windows and !opts.no_llvm;
 
-
     if (opts.enable_asan and !enableFastBuild(b)) {
         if (@hasField(Build.Module, "sanitize_address")) {
             if (opts.enable_fuzzilli) {
@@ -800,6 +799,11 @@ fn addInternalImports(b: *Build, mod: *Module, opts: *BunBuildOptions) void {
         });
     }
 
+    // libghostty-vt: Terminal VT emulator library from Ghostty
+    // Provides terminal escape sequence parsing, state management, input encoding
+    // Source is cloned by CMake to vendor/ghostty
+    addGhosttyModule(b, mod);
+
     // Finally, make it so all modules share the same import table.
     propagateImports(mod) catch @panic("OOM");
 }
@@ -832,6 +836,49 @@ fn validateGeneratedPath(path: []const u8) void {
     }
 }
 
+/// Adds the ghostty-vt module for terminal emulation functionality.
+/// Ghostty source is cloned to vendor/ghostty by CMake (see BuildGhosttyVt.cmake).
+///
+/// The ghostty-vt module provides:
+/// - VT escape sequence parsing (CSI, OSC, DCS, etc.)
+/// - Terminal state management (screen, cursor, colors)
+/// - Input encoding for terminal applications
+fn addGhosttyModule(b: *Build, mod: *Module) void {
+
+    // Create the ghostty-vt module from vendor/ghostty/src/lib_vt.zig
+    const ghostty_vt = b.createModule(.{
+        .root_source_file = b.path("vendor/ghostty/src/lib_vt.zig"),
+    });
+
+    // Add terminal_options - build configuration for the terminal module
+    ghostty_vt.addAnonymousImport("terminal_options", .{
+        .root_source_file = b.path("src/deps/ghostty/terminal_options.zig"),
+    });
+
+    // Add unicode_tables - stub tables for unicode property lookups
+    ghostty_vt.addAnonymousImport("unicode_tables", .{
+        .root_source_file = b.path("src/deps/ghostty/unicode_tables.zig"),
+    });
+
+    // Add symbols_tables - stub tables for symbol detection
+    ghostty_vt.addAnonymousImport("symbols_tables", .{
+        .root_source_file = b.path("src/deps/ghostty/symbols_tables.zig"),
+    });
+
+    // Add props module for Properties type used by unicode_tables
+    ghostty_vt.addAnonymousImport("props", .{
+        .root_source_file = b.path("vendor/ghostty/src/unicode/props.zig"),
+    });
+
+    // Add build_options for ghostty's SIMD code
+    ghostty_vt.addAnonymousImport("build_options", .{
+        .root_source_file = b.path("src/deps/ghostty/build_options.zig"),
+    });
+
+    // Export ghostty module to bun
+    mod.addImport("ghostty", ghostty_vt);
+}
+
 const WindowsShim = struct {
     exe: *Compile,
     dbg: *Compile,

cmake/targets/BuildBun.cmake

@@ -62,6 +62,7 @@ set(BUN_DEPENDENCIES
   LibArchive # must be loaded after zlib
   HdrHistogram # must be loaded after zlib
   Zstd
+  GhosttyVt # libghostty-vt terminal emulator library
 )
 
 include(CloneZstd)

cmake/targets/BuildGhosttyVt.cmake

@@ -0,0 +1,75 @@
+# Build libghostty-vt - Terminal VT emulator library from Ghostty
+# This clones the ghostty repository so Bun's build.zig can import it as a Zig module.
+#
+# libghostty-vt provides:
+# - Terminal escape sequence parsing
+# - Terminal state management (screen, cursor, scrollback)
+# - Input event encoding (Kitty keyboard protocol)
+# - OSC/DCS/CSI sequence handling
+#
+# Usage in Zig: @import("ghostty") gives access to the lib_vt.zig API
+
+register_repository(
+  NAME
+    ghostty
+  REPOSITORY
+    ghostty-org/ghostty
+  TAG
+    v1.1.3
+)
+
+# utfcpp - header-only UTF-8 library for error handling in SIMD code
+register_repository(
+  NAME
+    utfcpp
+  REPOSITORY
+    nemtrif/utfcpp
+  TAG
+    v4.0.5
+)
+
+# The ghostty source is cloned to ${VENDOR_PATH}/ghostty
+# Bun's build.zig will reference it directly as a Zig module
+
+# Build the SIMD acceleration library for ghostty
+# This provides optimized UTF-8 decoding for terminal escape sequence parsing
+set(GHOSTTY_SIMD_SRC ${VENDOR_PATH}/ghostty/src/simd/vt.cpp)
+
+add_library(ghostty-simd STATIC ${GHOSTTY_SIMD_SRC})
+
+target_include_directories(ghostty-simd PRIVATE
+  # Bun's compatibility headers (simdutf.h wrapper)
+  ${CWD}/src/deps/ghostty
+  # Ghostty's own headers
+  ${VENDOR_PATH}/ghostty/src
+  # Highway SIMD library (from Bun's vendor)
+  ${BUILD_PATH}/highway
+  ${VENDOR_PATH}/highway
+  # simdutf from webkit
+  ${WEBKIT_INCLUDE_PATH}
+  ${WEBKIT_INCLUDE_PATH}/wtf
+  # utfcpp for UTF-8 error handling
+  ${VENDOR_PATH}/utfcpp/source
+)
+
+target_compile_definitions(ghostty-simd PRIVATE
+  # Highway configuration
+  HWY_STATIC_DEFINE
+)
+
+# Enable exceptions for this file only - utfcpp's replace_invalid uses them
+set_source_files_properties(${GHOSTTY_SIMD_SRC} PROPERTIES
+  COMPILE_FLAGS "-fexceptions"
+)
+
+# Ensure dependencies are built first
+add_dependencies(ghostty-simd clone-ghostty clone-utfcpp)
+if(TARGET highway)
+  add_dependencies(ghostty-simd highway)
+endif()
+
+# Link ghostty-simd into bun
+target_link_libraries(${bun} PRIVATE ghostty-simd)
+
+# Link highway library
+target_link_libraries(${bun} PRIVATE ${BUILD_PATH}/highway/libhwy.a)

src/bun.js/api/Terminal.classes.ts

@@ -59,6 +59,76 @@ export default [
         getter: "getControlFlags",
         setter: "setControlFlags",
       },
+
+      // ----- Virtual Terminal (ghostty-vt) API -----
+      // These methods provide terminal emulation: parsing escape sequences,
+      // maintaining screen state (cells, cursor, colors), and rendering.
+
+      // Feed data to the virtual terminal parser
+      // This processes escape sequences and updates the screen state
+      feed: {
+        fn: "feed",
+        length: 1,
+      },
+
+      // Get a specific cell from the screen buffer at (x, y)
+      // Returns { char, wide, styled } or null if out of bounds
+      at: {
+        fn: "at",
+        length: 2,
+      },
+
+      // Get a line of text relative to the bottom of the screen
+      // line(0) = bottom line, line(1) = one above bottom, etc.
+      line: {
+        fn: "line",
+        length: 1,
+      },
+
+      // Get the full screen content as text (getter)
+      text: {
+        getter: "getText",
+      },
+
+      // Get cursor position { x, y, visible, style }
+      cursor: {
+        getter: "getCursor",
+      },
+
+      // Get current screen dimensions
+      cols: {
+        getter: "getCols",
+      },
+      rows: {
+        getter: "getRows",
+      },
+
+      // Get terminal title (set via OSC sequences)
+      title: {
+        getter: "getTitle",
+      },
+
+      // Check if terminal is in alternate screen mode
+      alternateScreen: {
+        getter: "getAlternateScreen",
+      },
+
+      // Get scrollback buffer size
+      scrollbackLines: {
+        getter: "getScrollbackLines",
+      },
+
+      // Clear the screen
+      clear: {
+        fn: "clearScreen",
+        length: 0,
+      },
+
+      // Reset terminal to initial state
+      reset: {
+        fn: "resetTerminal",
+        length: 0,
+      },
     },
   }),
 ];