Pre-C23, the C standard allows compilers to choose any integer type
that can represent all enum values, so small enums could be backed
by char or short. This breaks ABI compatibility with the Zig side,
which backs these enums with c_int.
Define GHOSTTY_ENUM_MAX_VALUE as INT_MAX in types.h and add it as
the last entry in every enum in include/ghostty/vt/. This forces
the compiler to use int as the backing type, matching c_int on all
targets. INT_MAX is used rather than a fixed constant because enum
constants must be representable as int; values above INT_MAX are a
constraint violation in standard C.
Document this convention in AGENTS.md.
Add ghostty_kitty_graphics_placement_source_rect which returns the
fully resolved and clamped source rectangle for a placement. This
applies kitty protocol semantics (width/height of 0 means full
image dimension) and clamps the result to the actual image bounds,
eliminating ~20 lines of protocol-aware logic from each embedder.
Add ghostty_kitty_graphics_placement_viewport_pos which converts a
placement's internal pin to viewport-relative grid coordinates.
The returned row can be negative when the placement's origin has
scrolled above the viewport, allowing embedders to compute the
correct destination rectangle for partially visible images.
Returns GHOSTTY_NO_VALUE only when the placement is completely
outside the viewport (bottom edge above the viewport or top edge
at or below the last row), so embedders do not need to perform
their own visibility checks. Partially visible placements always
return GHOSTTY_SUCCESS with their true signed coordinates.
Add a placement_iterator_set function that configures iterator
properties via an enum, following the same pattern as other set
functions in the C API (e.g. render_state_set). The first settable
option is a z-layer filter.
The GhosttyKittyPlacementLayer enum classifies placements into three
layers based on kitty protocol z-index conventions: below background
(z < INT32_MIN/2), below text (INT32_MIN/2 <= z < 0), and above text
(z >= 0). The default is ALL which preserves existing behavior.
When a layer filter is set, placement_iterator_next automatically
skips non-matching placements, so embedders no longer need to
reimplement the z-index bucketing logic or iterate all placements
three times per frame just to filter by layer.
Add the inverse of ghostty_terminal_grid_ref(), converting a grid
reference back to coordinates in a requested coordinate system
(active, viewport, screen, or history). This wraps the existing
internal PageList.pointFromPin and is placed on the terminal API
since it requires terminal-owned PageList state to resolve the
top-left anchor for each coordinate system.
Returns GHOSTTY_NO_VALUE when the ref falls outside the requested
range, e.g. a scrollback ref cannot be expressed in active
coordinates.
Expose Placement.pixelSize() and Placement.gridSize() as new C API
functions ghostty_kitty_graphics_placement_pixel_size() and
ghostty_kitty_graphics_placement_grid_size(). Both take the placement
iterator, image handle, and terminal, returning their results via
out params.
Rename the internal Zig method from calculatedSize to pixelSize to
pair naturally with gridSize — one returns pixels, the other grid
cells. Updated all callers including the renderer.
Expose Placement.rect() from the Zig kitty graphics storage as a new
C API function ghostty_kitty_graphics_placement_rect(). It takes the
terminal, image handle, and a positioned placement iterator, and
writes the bounding grid rectangle into a GhosttySelection out param.
Virtual placements return GHOSTTY_NO_VALUE.
Move all opaque handle typedefs (GhosttyTerminal, GhosttyKittyGraphics,
GhosttyRenderState, GhosttySgrParser, GhosttyFormatter, GhosttyOsc*)
into types.h so they are available everywhere without circular includes
and Doxygen renders them in the correct @ingroup sections.
Add a GhosttyKittyGraphicsImage opaque type and API for looking up
images by ID and querying their properties. This complements the
existing placement iterator by allowing direct image introspection.
The new ghostty_kitty_graphics_image() function looks up an image by
its ID from the storage, returning a borrowed opaque handle. Properties
are queried via ghostty_kitty_image_get() using the new
GhosttyKittyGraphicsImageData enum, which exposes id, number, width,
height, format, compression, and a borrowed data pointer with length.
Format and compression are exposed as their own C enum types
(GhosttyKittyImageFormat and GhosttyKittyImageCompression) rather
than raw integers.
Add a C API for iterating over Kitty graphics placements via the
new GhosttyKittyGraphics opaque handle. The API follows the same
pattern as the render state row iterator: allocate an iterator with
ghostty_kitty_graphics_placement_iterator_new, populate it from a
graphics handle via ghostty_kitty_graphics_get with the
PLACEMENT_ITERATOR data kind, advance with
ghostty_kitty_graphics_placement_next, and query per-placement
fields with ghostty_kitty_graphics_placement_get.
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 four new terminal options for configuring Kitty graphics at runtime
through the C API: storage limit, and the three loading medium flags
(file, temporary file, shared memory).
The storage limit setter propagates to all initialized screens and
uses setLimit which handles eviction when lowering the limit. The
medium setters similarly propagate to all screens. Getters read from
the active screen. All options compile to no-ops or return no_value
when kitty graphics are disabled at build time.
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.
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.
Add ghostty_grid_ref_hyperlink_uri to extract the OSC 8 hyperlink
URI from a cell at a grid reference position. Follows the same
buffer pattern as ghostty_grid_ref_graphemes: callers pass a buffer
and get back the byte length, or GHOSTTY_OUT_OF_SPACE with the
required size if the buffer is too small. Cells without a hyperlink
return success with length 0.
sys/types.h is a POSIX header that does not exist on MSVC. Move it
into the #else branch of the existing _MSC_VER guard that already
provides ssize_t via BaseTsd.h.
Rename the shared library visibility macro from GHOSTTY_EXPORT to
GHOSTTY_API across all public C headers. This applies to both the
libghostty-vt headers under include/ghostty/vt/ and the main
include/ghostty.h header.
This is a bit more idiomatic compared to other C libs and addresses the
fact that we're not always exporting...
The function previously took a size_t* out-parameter for the string
length. Since the JSON blob is now null-terminated, the len parameter
is unnecessary. Remove it from the Zig implementation, C header, and
the WASM example consumer which no longer needs to allocate and free
a usize just to read the length.
Add a new C API function that returns a comptime-generated JSON string
describing the size, alignment, and field layout of every C API extern
struct. This lets FFI consumers (particularly WASM) construct structs
by byte offset without hardcoding platform-specific layout.
The JSON is built at comptime using std.json.Stringify via a
StructInfo type that holds per-struct metadata and implements
jsonStringify. A StaticStringMap keyed by C struct name provides
lookup by name as well as iteration for the JSON serialization.
The function is declared in types.h alongside the other common types
and exported as ghostty_type_json.
Extend GHOSTTY_EXPORT annotations to all public function declarations
in include/ghostty/vt/ headers. Add GHOSTTY_EXPORT macro to types.h
with ifndef guard so both ghostty.h and VT headers share the same
definition without conflict.
Add a cpp-vt-stream example that verifies libghostty headers compile
cleanly in C++ mode. The example is a simplified C++ port of
c-vt-stream.
The headers used the C idiom `typedef struct Foo* Foo` for opaque
handles, which is invalid in C++ because struct tags and typedefs
share the same namespace. Fix all 12 opaque handle typedefs across the
headers to use a distinct struct tag with an Impl suffix, e.g.
`typedef struct GhosttyTerminalImpl* GhosttyTerminal`. This is a
source-compatible change for existing C consumers since the struct
tags were never referenced directly.
Add version (std.SemanticVersion) to the terminal build options so that
the terminal module has access to the application version at comptime.
The add() function breaks it out into version_string, version_major,
version_minor, version_patch, and version_build terminal options.
On the C API side, five new GhosttyBuildInfo variants expose these
through ghostty_build_info(). String values use GhosttyString; numeric
values use size_t. When no build metadata is present, version_build
returns a zero-length string.
The c-vt-build-info example is updated to query and print all version
fields.
Add ghostty_paste_encode() which encodes paste data for writing to
the terminal pty. It strips unsafe control bytes, wraps in bracketed
paste sequences when requested, and replaces newlines with carriage
returns for unbracketed mode. The input buffer is modified in place
and the encoded result is written to a caller-provided output buffer,
following the same buffer/out_written pattern as the other encode
functions like ghostty_size_report_encode.
Update the c-vt-paste example with an encode_example() demonstrating
the new function and add corresponding @snippet references in the
header documentation.
Add set/get support for foreground, background, cursor, and palette
default colors through ghostty_terminal_set and ghostty_terminal_get.
Four new set options (COLOR_FOREGROUND, COLOR_BACKGROUND, COLOR_CURSOR,
COLOR_PALETTE) write directly to the terminal color defaults. Passing
NULL clears the value for RGB colors or resets the palette to the
built-in default. All set operations mark the palette dirty flag for
the renderer.
Eight new get data types retrieve either the effective color (override
or default, via DynamicRGB.get) or the default color only (ignoring
any OSC overrides). Effective getters for RGB colors return the new
NO_VALUE result code when no color is configured. The palette getters
return the current or original palette respectively.
Adds the GHOSTTY_NO_VALUE result code for cases where a queried value
is simply not configured, distinct from GHOSTTY_INVALID_VALUE which
indicates a caller error.
The resize function now requires cell_width_px and cell_height_px
parameters and handles the full resize sequence: computing and
setting width_px/height_px on the terminal, clearing synchronized output mode
so changes display immediately, and encoding a mode 2048 in-band size report
via the write_pty callback when that mode is enabled.
A valid width/height px is critical for some applications and protocols
and some applications rely directly on in-band size reports, so this
change is necessary to support those use cases.
Add total_rows and scrollback_rows as new TerminalData variants
queryable through the existing ghostty_terminal_get interface, using the
cached O(1) total_rows field from PageList rather than introducing
standalone functions.
Add total_rows and scrollback_rows as new TerminalData variants
queryable through the existing ghostty_terminal_get interface,
using the cached O(1) total_rows field from PageList rather than
introducing standalone functions.
Previously ghostty_terminal_set required all values to be passed as
pointers to the value, even when the value itself was already a
pointer (userdata, function pointer callbacks). This forced callers
into awkward patterns like compound literals or intermediate
variables just to take the address of a pointer.
Now pointer-typed options (userdata and all callbacks) are passed
directly as the value parameter. Only non-pointer types like
GhosttyString still require a pointer to the value. This
simplifies InType to return the actual stored type for each option
and lets setTyped work with those types directly.
Add title and pwd as both gettable data keys
(GHOSTTY_TERMINAL_DATA_TITLE/PWD) and settable options
(GHOSTTY_TERMINAL_OPT_TITLE/PWD) in the C terminal API. Getting
returns a borrowed GhosttyString; setting copies the data into the
terminal via setTitle/setPwd.
The underlying Terminal.setTitle/setPwd now append a null sentinel so
that getTitle/getPwd can return sentinel-terminated slices ([:0]const
u8), which is useful for downstream consumers that need C strings.
Change ghostty_terminal_set to return GhosttyResult instead of void
so that the new title/pwd options can report allocation failures.
Existing option-setting calls cannot fail so the return value is
backwards-compatible for callers that discard it.
Add a comprehensive "Effects" section to the terminal module
documentation in terminal.h explaining the callback system that
lets embedding applications react to terminal-initiated events
(bell, title changes, pty writes, device queries, etc.). The
section includes a reference table of all available effects and
their triggers, plus @snippet references to the new example.
Add c-vt-effects example project demonstrating how to register
write_pty, bell, and title_changed callbacks, attach userdata,
and feed VT data that triggers each effect.
Assign handler.effects as a struct literal instead of setting fields
individually. This lets the compiler catch missing fields if new
effects are added to the Effects struct.
Also sort the callback function typedefs in vt/terminal.h
alphabetically (Bell, ColorScheme, DeviceAttributes, Enquiry, Size,
TitleChanged, WritePty, Xtversion).
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 GHOSTTY_TERMINAL_OPT_SIZE so C consumers can respond to
XTWINOPS size queries (CSI 14/16/18 t). The callback receives a
GhosttySizeReportSize out-pointer and returns true if the size is
available, or false to silently ignore the query. The trampoline
converts the bool + out-pointer pattern to the optional that the
Zig handler expects.
Add GHOSTTY_TERMINAL_OPT_TITLE_CHANGED so C consumers are notified
when the terminal title changes via OSC 0 or OSC 2 sequences. The
callback has the same fire-and-forget shape as bell.
Add GHOSTTY_TERMINAL_OPT_ENQUIRY and GHOSTTY_TERMINAL_OPT_XTVERSION
so C consumers can respond to ENQ (0x05) and XTVERSION (CSI > q)
queries. Both callbacks return a GhosttyString rather than using
out-pointers.
Introduce GhosttyString in types.h as a borrowed byte string
(ptr + len) backed by lib.String on the Zig side. This will be
reusable for future callbacks that need to return string data.
Without an xtversion callback the trampoline returns an empty
string, which causes the handler to report the default
"libghostty" version. Without an enquiry callback no response
is sent.
Add GHOSTTY_TERMINAL_OPT_BELL so C consumers can receive bell
notifications during VT processing. The bell trampoline follows
the same pattern as write_pty.
Move the C function pointer typedefs (WritePtyFn, BellFn) into
the Effects struct namespace to keep callback types co-located
with their storage and trampolines.
Add a typed option setter ghostty_terminal_set() following the
existing setopt pattern used by the key encoder and render state
APIs. This is the first step toward exposing stream_terminal
Handler.Effects through the C API.
The initial implementation includes a write_pty callback and a
shared userdata pointer. The write_pty callback is invoked
synchronously during ghostty_terminal_vt_write() when the terminal
needs to send a response back to the pty, such as DECRQM mode
reports or device status responses.
Trampolines are always installed at terminal creation time and
no-op when no C callback is set, so callers can configure
callbacks at any point without reinitializing the stream. The C
callback state is grouped into an internal Effects struct on the
TerminalWrapper to simplify adding more callbacks in the future.
MSVC's <sys/types.h> does not define ssize_t (it is a POSIX type).
This causes the translate-c build step to fail when translating
ghostty.h on Windows. Use SSIZE_T from <BaseTsd.h> which is the
Windows SDK equivalent.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Add a ghostty_alloc function that pairs with the existing
ghostty_free, giving embedders a symmetric malloc/free-style
API for buffer allocation through the libghostty allocator
interface. Returns NULL on allocation failure.
On Windows, Zig's built-in libc and MSVC's CRT maintain separate
heaps, so calling free() on memory allocated by the library causes
undefined behavior. Add ghostty_free() that frees through the same
allocator that performed the allocation, making it safe on all
platforms.
Update format_alloc docs and all examples to use ghostty_free()
instead of free().
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
