Add a C API for tracked pins, known as a tracked grid ref in C.
The new API can create tracked refs from terminal points, snapshot them
back to regular grid refs for cell access, convert them to coordinates,
move them to a new point, report when their semantic location was lost,
and free the tracked pin bookkeeping. This is backed by PageList tracked
pins and exposed through the libghostty-vt export layer and headers.
Demonstrates the sys interface for Kitty Graphics Protocol PNG
support. The example installs a PNG decode callback via
ghostty_sys_set, creates a terminal with image storage enabled,
and sends an inline 1x1 PNG image through vt_write. Snippet
markers are wired up to the sys.h doxygen docs.
The terminal sys module provides runtime-swappable function pointers
for operations that depend on external implementations (e.g. PNG
decoding). This exposes that functionality through the C API via a
ghostty_sys_set() function, modeled after the ghostty_terminal_set()
enum-based option pattern.
Embedders can install a PNG decode callback to enable Kitty Graphics
Protocol PNG support. The callback receives a userdata pointer
(set via GHOSTTY_SYS_OPT_USERDATA) and a GhosttyAllocator that must
be used to allocate the returned pixel data, since the library takes
ownership of the buffer. Passing NULL clears the callback and
disables the feature.
Add a new GhosttySelection C API type (selection.h / c/selection.zig)
that pairs two GhosttyGridRef endpoints with a rectangle flag. This
maps directly to the internal Selection type using untracked pins.
The formatter terminal options gain an optional selection pointer.
When non-null the formatter restricts output to the specified range
instead of emitting the entire screen. When null the existing
behavior of formatting the full screen is preserved.
Rename device_status.h to device.h and add C-compatible structs for
device attributes (DA1/DA2/DA3) responses. The new header includes
defines for all known conformance levels, DA1 feature codes, and DA2
device type identifiers.
Add a GhosttyTerminalDeviceAttributesFn callback that C consumers can
set via GHOSTTY_TERMINAL_OPT_DEVICE_ATTRIBUTES. The callback follows
the existing bool + out-pointer pattern used by color_scheme and size
callbacks. When the callback is unset or returns false, the trampoline
returns a default VT220 response (conformance level 62, ANSI color).
The DA1 primary features use a fixed [64]uint16_t inline array with a
num_features count rather than a pointer, so the entire struct is
value-typed and can be safely copied without lifetime concerns.
Change device_status.ColorScheme from a plain Zig enum to
lib.Enum so it uses c_int backing when targeting the C ABI.
Add a color_scheme callback to the C terminal effects, following
the bool + out-pointer pattern used by the size callback. The
trampoline converts between the C calling convention and the
internal stream handler color_scheme effect, returning null when
no callback is set.
Add device_status.h header with GhosttyColorScheme enum and wire
it through terminal.h as GHOSTTY_TERMINAL_OPT_COLOR_SCHEME (= 7)
with GhosttyTerminalColorSchemeFn.
Add a new C API function ghostty_build_info() that exposes compile-time
build options to library consumers. This allows callers to query whether
SIMD, Kitty graphics protocol, and tmux control mode support were
enabled at build time.
Add a C-facing GhosttyRenderStateColors sized struct and a
ghostty_render_state_colors_get accessor so renderers can read
background, foreground, cursor color state, and palette data directly
from the render state.
Introduce the first public C render-state surface for libghostty-vt.
Before this change, the render-state path was only available in Zig,
so C embedders had no direct way to create and update that cache.
Add an opaque GhosttyRenderState type with new, update, and free
entry points, then wire those symbols through the C API bridge and
library exports. Keep the surface intentionally minimal for now so
ownership and update behavior are established before adding read
accessors.
Add a c-vt-grid-ref example that demonstrates the terminal and grid
reference APIs end-to-end. The example creates a small 10x3 terminal,
writes text with mixed styles via VT sequences, then iterates over
every cell in the active area using ghostty_terminal_grid_ref. For
each cell it extracts the codepoint, and for each row it inspects
the wrap flag and the style bold attribute.
The grid_ref.h defgroup gains a @snippet reference to the new example,
and vt.h gets the corresponding @example entry and @ref listing.
Add opaque GhosttyCell (uint64_t) and GhosttyRow (uint64_t) types that
bitcast to the internal packed Cell and Row structs from page.zig. Each
type has a corresponding data enum and getter function following the
same pattern as ghostty_terminal_get.
ghostty_cell_get supports extracting codepoint, content tag, wide
property, has_text, has_styling, style_id, has_hyperlink, protected,
and semantic_content. ghostty_row_get supports wrap, wrap_continuation,
grapheme, styled, hyperlink, semantic_prompt, kitty_virtual_placeholder,
and dirty.
The cell and row types and functions live in a new screen.h header,
separate from terminal.h, with terminal.h including screen.h for
convenience.
Expose the terminal Style struct to the C API as GhosttyStyle, a
sized struct with foreground, background, and underline colors
(as tagged unions) plus boolean text decoration flags.
Add ghostty_style_default() to obtain the default style and
ghostty_style_is_default() to check whether a style has all
default values. Wire both through c/style.zig, main.zig, and
lib_vt.zig with the corresponding header in vt/style.h.
Add ghostty_size_report_encode() to libghostty-vt, following the
same pattern as focus encoding: a single stateless function that
writes a terminal size report escape sequence into a caller-provided
buffer.
The size_report.zig Style enum and Size struct now use lib.Enum and
lib.Struct so the types are automatically C-compatible when building
with c_abi, eliminating the need for duplicate type definitions in
the C wrapper. The C wrapper in c/size_report.zig re-exports these
types directly and provides the callconv(.c) encode entry point.
Supports mode 2048 in-band reports and XTWINOPS responses (CSI 14 t,
CSI 16 t, CSI 18 t).
Add modes.h with GhosttyModeTag, a uint16_t typedef matching the
Zig ModeTag packed struct layout (bits 0-14 for the mode value,
bit 15 for the ANSI flag). Three inline helper functions provide
construction and inspection: ghostty_mode_tag_new,
ghostty_mode_tag_value, and ghostty_mode_tag_ansi.
Add focus event encoding (CSI I / CSI O) to the libghostty-vt public
API, following the same patterns as key and mouse encoding.
The focus Event enum uses lib.Enum for C ABI compatibility. The C API
provides ghostty_focus_encode() which writes into a caller-provided
buffer and returns GHOSTTY_OUT_OF_SPACE with the required size when
the buffer is too small.
Also update key and mouse encoders to return GHOSTTY_OUT_OF_SPACE
instead of GHOSTTY_OUT_OF_MEMORY for buffer-too-small errors,
reserving OUT_OF_MEMORY for actual allocation failures. Update all
corresponding header documentation.
Add a new c-vt-mouse-encode example that demonstrates how to use the
mouse encoder C API. The example creates a mouse encoder configured
with SGR format and normal tracking mode, sets up terminal geometry
for pixel-to-cell coordinate mapping, and encodes a left button press
event into a terminal escape sequence.
Mirrors the structure of the existing c-vt-key-encode example. Also
adds the corresponding @example doxygen reference in vt.h.
Expose the internal mouse encoding functionality through the C API,
following the same pattern as the existing key encoding API. This
allows external consumers of libvt to encode mouse events into
terminal escape sequences (X10, UTF-8, SGR, URxvt, SGR-Pixels).
The API is split into two opaque handle types: GhosttyMouseEvent
for building normalized mouse events (action, button, modifiers,
position) and GhosttyMouseEncoder for converting those events into
escape sequences. The encoder is configured via a setopt interface
supporting tracking mode, output format, renderer geometry, button
state, and optional motion deduplication by last cell.
Encoder state can also be bulk-configured from a terminal handle
via ghostty_mouse_encoder_setopt_from_terminal. Failed encodes due
to insufficient buffer space report the required size without
mutating deduplication state.
Add an example showing how to use the ghostty-vt terminal and
formatter APIs from C. The example creates a terminal, writes
VT-encoded content with cursor movement and styling sequences,
then formats the screen contents as plain text using the formatter
API.
Add a size field as the first member of formatter option structs
(TerminalOptions, TerminalOptions.Extra, ScreenOptions.Extra) for ABI
compatibility. This allows adding new fields without breaking callers
compiled against older versions of the struct.
Introduce include/ghostty/vt/types.h as the foundational header
containing GhosttyResult and the GHOSTTY_INIT_SIZED macro for
zero-initializing sized structs. Remove the separate result.h header,
moving its contents into types.h.
This exposes the SGR parser to the C and Wasm APIs. An example is shown
in c-vt-sgr.
Compressed example:
```c
#include <assert.h>
#include <stdio.h>
#include <ghostty/vt.h>
int main() {
// Create parser
GhosttySgrParser parser;
assert(ghostty_sgr_new(NULL, &parser) == GHOSTTY_SUCCESS);
// Parse: ESC[1;31m (bold + red foreground)
uint16_t params[] = {1, 31};
assert(ghostty_sgr_set_params(parser, params, NULL, 2) == GHOSTTY_SUCCESS);
printf("Parsing: ESC[1;31m\n\n");
// Iterate through attributes
GhosttySgrAttribute attr;
while (ghostty_sgr_next(parser, &attr)) {
switch (attr.tag) {
case GHOSTTY_SGR_ATTR_BOLD:
printf("✓ Bold enabled\n");
break;
case GHOSTTY_SGR_ATTR_FG_8:
printf("✓ Foreground color: %d (red)\n", attr.value.fg_8);
break;
default:
break;
}
}
ghostty_sgr_free(parser);
return 0;
}
```
**AI disclosure:** Amp wrote most of the C headers, but I verified it
all. https://ampcode.com/threads/T-d9f145cb-e6ef-48a8-ad63-e5fc85c0d43e
This adds a set of Wasm convenience functions to ease memory management.
These are all prefixed with `ghostty_wasm` and are documented as part of
the standard Doxygen docs.
I also added a very simple single-page HTML example that demonstrates
how to use the Wasm module for key encoding.
This also adds a bunch of safety checks to the C API to verify that
valid values are actually passed to the function. This is an easy to hit
bug.
**AI disclosure:** The example is AI-written with Amp. I read through
all the code and understand it but I can't claim there isn't a better
way, I'm far from a JS expert. It is simple and works currently though.
Happy to see improvements if anyone wants to contribute.
This also changes OSC strings to be null-terminated to ease lib-vt
integration. This shouldn't have any practical effect on terminal
performance, but it does lower the maximum length of OSC strings by 1
since we always reserve space for the null terminator.
Mitchell Hashimoto