# Version history > [!NOTE] > Consult the [migration guide](migration) to migrate between major Koffi versions. ## Koffi 2 ### Koffi 2.10 #### Koffi 2.10.1 (2025-01-24) - Fix detection of ARM32 in build script in some cases - Fix wrong path for ARM32 prebuild #### Koffi 2.10.0 (2024-12-22) - Allow [redefinition of opaque types](misc#circular-references) to concrete struct or union - Update documentation style ### Koffi 2.9 #### Koffi 2.9.2 (2024-11-08) - Fix non-aligned pointers when pushing UTF-16 and UTF-32 string parameters - Various documentation fixes and improvements #### Koffi 2.9.1 (2024-09-23) - Fix x86 32-bit support regression in 2.9.0 - Add missing TS definition for `koffi.alloc()` - Support `koffi.load(null)` in TS definition file #### Koffi 2.9.0 (2024-07-22) - Add support for char32_t and wchar_t (wide) strings - Include Linux/musl x64 prebuild (based on Alpine) ### Koffi 2.8 #### Koffi 2.8.11 (2024-06-19) - Work around MSVC compiler bug introduced in Visual Studio 17.10 > [!WARNING] > Use on platforms without pre-built binaries is broken in Koffi 2.8.10, skip this version. #### Koffi 2.8.9 (2024-05-17) - Fix ABI issue regarding bool return values on x86_64 (and possibly other platforms) #### Koffi 2.8.8 (2024-04-26) - Support use of buffers with mismatched size (truncation or zero-filling) #### Koffi 2.8.7 (2024-04-23) - Improve compatibility with SEHOP on Windows ([@longhun12346](https://github.com/longhun12346)) #### Koffi 2.8.6 (2024-04-12) - Support [loading library](functions#loading-options) with RTLD_DEEPBIND where supported #### Koffi 2.8.5 (2024-04-11) - Prevent obviously invalid type and member names - Fix possible infinite loop / UB for `koffi.load()` errors on POSIX systems - Fix null return value instead of exception for some errors in `koffi.load()` on Windows #### Koffi 2.8.4 (2024-04-09) - Use simpler workaround for Node 20.12+ and 21.6+ to avoid excessive memory use > [!WARNING] > Some pre-built binaries are missing in Koffi 2.8.3, skip this version. #### Koffi 2.8.2 (2024-04-07) - Support [loading library](functions#loading-options) with RTLD_GLOBAL on POSIX platforms #### Koffi 2.8.1 (2024-04-04) - Fix incompatibility with Node 20.12+ and 21.6+ #### Koffi 2.8.0 (2024-02-12) - Support pushing pointers for string arguments - Add `koffi.alloc()` for [stable pointers](output#stable-pointers) ### Koffi 2.7 #### Koffi 2.7.4 (2024-02-04) - Support callbacks happening on main thread but outside JS call (such as during event loop) - Improve stability after `koffi.reset()` - Expose internal Node/NAPI `env` pointer - Name main Koffi API functions #### Koffi 2.7.3 (2024-01-26) - Support decoding NULL terminated arrays #### Koffi 2.7.2 (2024-01-15) - Add missing TypeScript declaration for `koffi.free()` - Fix TypeScript declaration of `koffi.encode()` - Try to improve compatibility with webpack #### Koffi 2.7.1 (2024-01-02) - Support C-like `int[3]` syntax for [fixed array types](input#fixed-size-c-arrays) - Refuse type specifiers with invalid tokens at the end (previously ignored) #### Koffi 2.7.0 (2023-12-21) - Support alternative [callback calling convention](callbacks#callback-types) in classic syntax - Change syntax for [calling conventions](functions#calling-conventions) with classic syntax - Drop unused "internal" property from Koffi ### Koffi 2.6 #### Koffi 2.6.12 (2023-12-11) - Fix possible crash introduced in Koffi 2.6.11 #### Koffi 2.6.11 (2023-12-05) - Speed up resolving simple and often used type names - Fix use of optional length argument with [koffi.encode()](variables#encode-to-c-memory) #### Koffi 2.6.10 (2023-11-29) - Protect GetLastError() value from Node.js and V8 on Windows #### Koffi 2.6.9 (2023-11-25) - Search in DLL directory for additional dependencies on Windows - Ignore prototype properties when making structs or unions - Show detected version of Node when not adequate - Minor documentation fixes > [!WARNING] > Loading Win32 system libraries can fail in Koffi 2.6.8, skip this version. #### Koffi 2.6.6 (2023-10-28) - Better handle errors while making struct or union types #### Koffi 2.6.5 (2023-10-28) - Allow self-referential structs and unions - Fix rare Node.js "FATAL ERROR" with some invalid type specifiers #### Koffi 2.6.4 (2023-10-26) - Fix build issue with recent Visual Studio versions #### Koffi 2.6.3 (2023-10-17) - Add indirect loading script to help some bundlers > [!WARNING] > Pre-built binaries don't work correctly in Koffi 2.6.2, skip this version. #### Koffi 2.6.1 (2023-09-18) - Support string direction qualifiers in classic function definitions - Fix possible off-by-one array access when parsing type name #### Koffi 2.6.0 (2023-09-13) **New features:** - Use [koffi.symbol()](variables#variable-definitions) to make pointers to exported variables (or other symbols) - Use [koffi.encode()](variables#encode-to-c-memory) to explictly encode data from JS to C memory - Use shared library [lazy-loading](functions#loading-options) (RTLD_LAZY) on POSIX platforms **Other changes:** - Print more helpful error for Win32/Win64 DLL mismatches - Add missing 'Union' primitive value in TS definition file ### Koffi 2.5 #### Koffi 2.5.20 (2023-08-31) - Fix possible crash with async registered callbacks introduced in Koffi 2.5.19 - Various documentation fixes and improvements #### Koffi 2.5.19 (2023-08-29) - Create thread-safe function broker lazily - Add [koffi.reset()](misc#reset-internal-state) for type names and async broker #### Koffi 2.5.18 (2023-08-27) - Fix compatibility with Electron #### Koffi 2.5.16 (2023-08-25) - Run Koffi tests through usual index.js entry point - Fix DLL error when using Koffi from NW.js on Windows - Simplify NW.js Koffi example > [!WARNING] > Pre-built binaries don't work correctly in Koffi 2.5.13 to 2.5.15, skip those versions. #### Koffi 2.5.12 (2023-08-21) - Fix native module bundling for FreeBSD ARM64 and Linux RISC-V 64 - Increase maximum number of parameters to 64 #### Koffi 2.5.11 (2023-08-03) - Support casting function pointers with [koffi.as()](pointers#handling-void-pointers) - Build in C++20 mode #### Koffi 2.5.10 (2023-08-01) - Fix CMake regression when client has to build Koffi #### Koffi 2.5.9 (2023-07-28) **Main changes:** - Use bundler-friendly static require calls in Koffi - Add packaging examples to documentation **Other changes:** - Add missing unload() export to TS file - Add export for koffi.types in TS file #### Koffi 2.5.8 (2023-07-26) - Add more search paths for native Koffi modules - Add section [about bundling](start#bundling-koffi) to documentation #### Koffi 2.5.7 (2023-07-19) - Point package to new repository #### Koffi 2.5.6 (2023-07-19) - Increase limit of output parameters from 16 to 32 #### Koffi 2.5.5 (2023-07-17) - Support decoding non-char null-terminated arrays #### Koffi 2.5.4 (2023-07-14) - Fix `koffi.pointer()` not accepting disposable types - Fix potential issues when making pointers to anonymous types #### Koffi 2.5.3 (2023-07-05) - Add missing union exports in TS definition file - Fix some parameter names in TS definition file #### Koffi 2.5.2 (2023-07-04) - Default initialize unset object/struct members #### Koffi 2.5.1 (2023-06-20) - Fix crash with some struct types in System V 64 ABI - Always use direct passthrough for buffer arguments #### Koffi 2.5.0 (2023-06-20) **New features:** - Support [union types](unions) **Other fixes:** - Fix ABI for single-float aggregate return on i386 BSD systems - Don't mess with Node.js signal handling on POSIX systems ### Koffi 2.4 #### Koffi 2.4.2 (2023-06-04) - Support calling variadic function pointers - Add documentation for function pointers #### Koffi 2.4.1 (2023-06-03) **Main changes:** - Support [decoding function pointers](functions#decode-pointer-to-function) to callable functions - Support calling function pointers with [koffi.call()](functions#call-pointer-directly) - Deprecate `koffi.callback` in favor of `koffi.proto` **Other changes:** - Increase maximum number of callbacks to 8192 - Build Koffi with static CRT on Windows - Reorganize Koffi data conversion documentation - Add deprecated `koffi.handle` to TS file ### Koffi 2.3 #### Koffi 2.3.20 (2023-05-15) - Support explicit library unloading with `lib.unload()` #### Koffi 2.3.19 (2023-04-21) - Actually allow non-ambiguous [string] values for `void *` arguments #### Koffi 2.3.18 (2023-04-21) - Fix possible crash on exit caused by unregistered callbacks #### Koffi 2.3.17 (2023-04-20) - Allow strings for input `void *`, `int8_t *` and `int16_t *` pointer arguments - Support using `[string]` (single-element string arrays) for polymorphic input/output arguments #### Koffi 2.3.16 (2023-04-11) - Fix Windows ARM64 build to work with official Node.js version - Compile Windows builds with Visual Studio 2022 17.5.3 - Support null in `koffi.free()` and `koffi.address()` #### Koffi 2.3.15 (2023-04-10) - Improve manual decoding of 0-terminated strings - Add checks around array conversion hints #### Koffi 2.3.14 (2023-04-05) - Add `koffi.errno()` function to get and set current errno value - Add `koffi.os.errno` object with valid errno codes #### Koffi 2.3.13 (2023-03-30) - Add `koffi.address()` to get the raw value of a wrapper pointer #### Koffi 2.3.12 (2023-03-30) - Fix broken syntax in TS definition file - Add missing exported properties in TS file #### Koffi 2.3.11 (2023-03-30) **Main changes:** - Allow numbers and BigInts to be used for pointer arguments **Other changes:** - Use SQLITE_TRANSIENT in SQLite test code - Avoid using `statx()` to allow compilation with glibc < 2.28 - Reorganize NPM package files to be less convoluted #### Koffi 2.3.9 (2023-03-10) - Relicense under MIT license #### Koffi 2.3.8 (2023-02-28) - Disable non-ready union support - Simplify Windows stack allocation and drop NOACCESS and GUARD pages - Adjust Windows TEB SEH chain and GuaranteedStackBytes for Koffi calls #### Koffi 2.3.7 (2023-02-27) - Fix missing require in index.js ([@gastonFrecceroNapse](https://github.com/gastonFrecceroNapse)) - Reduce NPM package bloat (from 65 MB to 20 MB) caused by changes in 2.3.6 #### Koffi 2.3.6 (2023-02-26) - Fix broken TS definition file - Keep all prebuilt binaries and load correct one at runtime #### Koffi 2.3.5 (2023-02-24) **Main fixes:** - Fix rare random crashes with async callbacks - Fix some bugs with RISC-V 64 ABI **Other changes:** - Expose array type hint in `koffi.introspect()` - Add missing `koffi.array()` export in TS definition - Make KoffiFunction more flexible in TS definition ([@insraq](https://github.com/insraq)) - Add a KoffiFunc helper type in TS typing ([@insraq](https://github.com/insraq)) - Mark optional properties in TS TypeInfo class - Minor performance improvements #### Koffi 2.3.4 (2023-01-31) - Fix error when installing Koffi on Windows (2.3.2) #### Koffi 2.3.2 (2023-01-30) **Main changes:** - Fix type parser issues (such as ignoring some [disposable qualifiers](pointers#disposable-types)) - Fix crash when using disposable types in output parameters - Add basic [koffi.stats()](misc#usage-statistics) interface **Other changes:** - Avoid CNoke dependency - Clear out development dependencies from package.json #### Koffi 2.3.1 (2023-01-30) - Error out when trying to use ambiguous `void *` arguments (input and/or output) - Adjust TypeScript definitions ([@insraq](https://github.com/insraq)) - Fix possible crash when parsing invalid prototype #### Koffi 2.3.0 (2023-01-25) **Main changes:** - Allow buffers (TypedArray or ArrayBuffer) values for input and/or output pointer arguments (for polymorphic arguments) - Support opaque buffers (TypedArray or ArrayBuffer) values in `koffi.decode()` to [decode output buffers](output#output-buffers) - Decode non-string types as arrays when an [explicit length is passed to koffi.decode()](callbacks#decoding-pointer-arguments) **Other changes:** - Drop TypedArray type check for array and pointer values (only the size matters) - Allow ArrayBuffer everywhere TypedArray is supported - Add TypeScript definition for Koffi ([@insraq](https://github.com/insraq)) - Improve documentation about opaque and polymorphic structs - Improve documentation for `koffi.decode()` - Reduce NPM package size (from 100 MB to 25 MB) by removing test code and dependencies ### Koffi 2.2 #### Koffi 2.2.5 (2023-01-23) - Relicense Koffi under LGPL 3.0 #### Koffi 2.2.4 (2023-01-19) - Fix memory leak on Windows (in Koffi 2.2.3) when running many async calls - Reorganize documentation pages #### Koffi 2.2.3 (2023-01-17) - Support native code that uses [Structured Exception Handling (SEH)](https://learn.microsoft.com/en-us/cpp/cpp/structured-exception-handling-c-cpp) on Windows (x86, x64 and ARM64) - Try to use ebp/rbp as frame pointer in x86/x64 ASM code #### Koffi 2.2.2 (2023-01-14) **Main fixes:** - Support transparent [asynchronous callbacks](callbacks#asynchronous-callbacks) - Expand from a maximum of 16+16 to 1024 callbacks running in parallel **Other fixes:** - Fix bundler support by removing shebang from index.js - Fix bugs when loading Koffi multiples times in same process (context aware module) - Check N-API version when module is loaded - Optimize callback unregistration #### Koffi 2.2.1 (2022-12-21) - Fix crash when [calling callback again after FFI call inside previous callback](https://github.com/Koromix/rygel/issues/15) #### Koffi 2.2.0 (2022-12-20) **New features:** - Add [koffi.decode()](callbacks#decoding-pointer-arguments) for callback pointer arguments - Support transparent [output string parameters](output#string-buffer-example) - Add `koffi.offsetof()` utility function - Support optional *this* binding in `koffi.register()` **Other fixes:** - Correctly validate output parameter types - Fix assertion with `void *` parameters ### Koffi 2.1 #### Koffi 2.1.5 (2022-11-27) - Add missing README file to NPM package #### Koffi 2.1.4 (2022-11-25) **Main changes:** - Increase maximum type size from 32 kiB to 64 MiB - Add configurable option for maximum type size **Other changes:** - Moved Koffi to a new repository: https://github.com/Koromix/rygel/ #### Koffi 2.1.3 (2022-10-31) - Support up to 16 output parameters (instead of 8) #### Koffi 2.1.2 (2022-10-31) - Support up to 8 output parameters (instead of 4) #### Koffi 2.1.1 (2022-08-16) - Fix potential memory allocation bugs #### Koffi 2.1.0 (2022-08-13) **Main changes:** - Add [koffi.as()](pointers#handling-void-pointers) to support polymorphic APIs based on `void *` parameters - Add [endian-sensitive integer types](input#endian-sensitive-integers): `intX_le_t`, `intX_be_t`, `uintX_le_t`, `uintX_be_t` - Accept typed arrays for `void *` parameters - Introduce `koffi.opaque()` to replace `koffi.handle()` (which remains supported until Koffi 3.0) - Support JS Array and TypedArray to fill struct and array pointer members **Other changes:** - Improve global performance with inlining and unity builds - Add `size_t` primitive type - Support member-specific alignement values in structs - Detect impossible parameter and return types (such as non-pointer opaque types) - Various documentation fixes and improvements ### Koffi 2.0 #### Koffi 2.0.1 (2022-07-30) - Return `undefined` (instead of null) for `void` functions #### Koffi 2.0.0 (2022-07-29) **Major new features:** - Add [disposable types](pointers#disposable-types) for automatic disposal of C values (such as heap-allocated strings) - Add support for [registered callbacks](callbacks#registered-callbacks), that can be called after the initial FFI call - Support named pointer types - Support complex type specifications outside of prototype parser **Minor new features:** - Support type aliases with `koffi.alias()` - Add `koffi.resolve()` to resolve type strings - Expose all primitive type aliases in `koffi.types` - Correctly pass exceptions thrown in JS callbacks **Breaking API changes:** - Change handling of callback types, which must be used through pointers - Change handling of opaque handles, which must be used through pointers - Support all types in `koffi.introspect(type)` Consult the [migration guide](migration) for more information. ## Koffi 1 ### Koffi 1.3 #### Koffi 1.3.12 (2022-07-27) - Fix support for Yarn package manager #### Koffi 1.3.11 (2022-07-26) - Fix broken parsing of `void *` when used for first parameter #### Koffi 1.3.10 (2022-07-25) **Main fixes:** - Fix support for callbacks with more than 4 parameters on Windows x64 - Fix support for callbacks with multiple floating-point arguments on ARM32 platforms - Fix possibly incorrect conversion for uint32_t callback parameters **Other changes:** - Various documentation fixes and improvements #### Koffi 1.3.9 (2022-07-15) - Fix prebuild compatibility with Electron on Windows x64 #### Koffi 1.3.8 (2022-07-12) **Main changes:** - Prevent callback reuse beyond FFI call - Add BTI support for AAarch64 platforms (except Windows) **Other changes:** - Fix and harmonize a few error messages #### Koffi 1.3.7 (2022-07-07) **Main fixes:** - Fix crash when using callbacks inside structs - Support for null strings in record members **Other changes:** - Add intptr_t and uintptr_t primitive types - Add str/str16 type aliases for string/string16 - Various documentation fixes and improvements #### Koffi 1.3.6 (2022-07-01) **Main fixes:** - Fix install error with Node < 15 on Windows (build system bug) **Other changes:** - Detect incompatible Node.js versions when installing Koffi - Prebuild with Clang for Windows x64 and Linux x64 binaries - Various documentation improvements #### Koffi 1.3.5 (2022-06-25) **Main changes:** - Fix memory leak when many async calls are running - Add configurable limit for maximum number of async calls (max_async_calls) **Other changes:** - Reduce default async memory stack and heap size - Various documentation improvements #### Koffi 1.3.4 (2022-06-24) - Fix possible OpenBSD i386 crash with `(void)` functions #### Koffi 1.3.3 (2022-06-24) **Main fixes:** - Fix misconversion of signed integer return value as unsigned **Other changes:** - Support `(void)` (empty) function signatures - Disable unsafe compiler optimizations - Various documentation improvements #### Koffi 1.3.2 (2022-06-23) - Support compilation in C++14 mode (graceful degradation) - Support older toolchains on Linux (tested on Debian 9) #### Koffi 1.3.1 (2022-06-22) - The prebuilt binary is tested when Koffi is installed, and a rebuild happens if it fails to load #### Koffi 1.3.0 (2022-06-22) **Major changes:** - Expand and move documentation to https://koffi.dev/ - Support JS arrays and TypedArrays for pointer arguments (input, output and mixed) **Other changes:** - Convert NULL string pointers to null instead of crashing (return values, struct and array members, callbacks) - Default to 'string' array hint for char, char16 and char16_t arrays - Fix definition of long types on Windows x64 (LLP64 model) - Restrict automatic string conversion to signed char types - Detect floating-point ABI before using prebuilt binaries (ARM32, RISC-V) - Forbid duplicate member names in struct types ### Koffi 1.2 #### Koffi 1.2.4 (2022-06-12) - Windows ARM64 is now supported #### Koffi 1.2.3 (2022-06-11) - A prebuilt binary for macOS ARM64 (M1) is now included #### Koffi 1.2.1 (2022-06-11) This entry documents changes since version 1.1.0. **New features:** - JS functions can be used as C callbacks (cdecl, stdcall) on all platforms - RISC-V 64 LP64D ABI is supported (LP64 is untested) - Expose settings for memory usage of synchronous and asynchronous calls - Transparent conversion between C buffers and strings - Tentative support for Windows ARM64 (untested) **Main fixes:** - Fix excessive stack alignment of structs on x86 platforms - Fix potential problems with big int64_t/uint64_t values - Fix possible struct layout errors in push/pop code - Fix alignment issues in ARM32 push code - Fix incomplete/buggy support for HFA structs on ARM32 and ARM64 - Fix crashes on OpenBSD caused by missing MAP_STACK flag - Fix non-sense "duplicate array type" errors - Fix value `koffi.internal` to false in module (normal) builds - Make sure we have a redzone below the stack for all architectures - Use slower allocation for big objects instead of failing # Todo list The following features and improvements are planned, not necessarily in that order: - Port Koffi to Loong64 ISA and ABI - Port Koffi to PowerPC (POWER9+) ISA and ABI - Optimize passing of structs and arrays (with auto-generated JS) - Automate Windows/AArch64 (qemu) and macOS/AArch64 (how? ... thanks Apple) tests - Create a real-world example, using several libraries (Raylib, SQLite, libsodium) to illustrate various C API styles - Add simple struct type parser - Fix assembly unwind and CFI directives for better debugging experience