# koffi

> Fast and easy-to-use dynamic C FFI (foreign function interface) for Node.js

Latest version **3.3.2** (published 2026-09-27) · MIT license · 0 weekly downloads

## Install

```sh
npm install koffi
pnpm add koffi
yarn add koffi
bun add koffi
```

## Health

**Score 65/100 (B)** — status: active.

Positive: has types; esm support; no vulnerabilities; recently updated; high maintenance score.

Warnings: low downloads.

## Facts

| | |
|---|---|
| Version | 3.3.2 |
| Published | 2026-09-27 |
| First published | 2022-02-23 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Dependencies | 0 |
| Unpacked size | 1.6 MB |
| Known vulnerabilities | 0 |
| Install scripts | yes |
| Author | Niels Martignène |
| Maintainers | koromix |
| Keywords | foreign, function, interface, ffi, binding, c, napi |

## Links

- npm: https://www.npmjs.com/package/koffi
- Repository: https://github.com/Koromix/koffi
- Homepage: https://koffi.dev/
- Issues: https://github.com/Koromix/koffi/issues
- Funding: https://liberapay.com/Koromix
- npm.io page: https://npm.io/package/koffi

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## Recent versions

- 3.3.2 (latest) — 2026-09-27
- 3.3.1 — 2026-09-19
- 3.3.0 — 2026-09-14
- 3.2.1 — 2026-09-04
- 3.2.1-beta.1 — 2026-09-03
- 3.2.0 — 2026-09-02
- 3.1.6 — 2026-08-20
- 3.1.5 — 2026-08-13
- 3.1.4 — 2026-07-30
- 3.1.3 — 2026-07-30
- 3.1.2 — 2026-07-21
- 2.16.3 — 2026-07-21
- 3.1.1 — 2026-07-10
- 3.1.0 — 2026-06-29
- 3.0.2 — 2026-05-26
- … 270 more at https://npm.io/package/koffi/versions

## README

# Overview

Koffi is a fast and easy-to-use dynamic C FFI module for Node.js, featuring:

* Low-overhead compared to a static Node-API implementation (see [benchmarks](https://koffi.dev/benchmarks))
* Support for primitive and aggregate data types (structs and fixed-size arrays), both by reference (pointer) and by value
* Support for synchronous and asynchronous calls
* Javascript functions can be used as C callbacks
* Well-tested code base for popular OS/architecture combinations

The following combinations of OS and architectures __are officially supported and tested__ at the moment:

ISA / OS           | Windows  | Linux/glibc | Linux/musl  | macOS    | FreeBSD     | OpenBSD     | Android
------------------ | -------- | ----------- | ----------- | -------- | ----------- | ----------- | -----------
x86_64 (AMD64)     | ✅ Yes   | ✅ Yes      | ✅ Yes      | ✅ Yes   | ✅ Yes      | ✅ Yes      | ✅ Yes
ARM64 (AArch64) LE | ✅ Yes   | ✅ Yes      | ✅ Yes      | ✅ Yes   | ✅ Yes      | ✅ Yes      | ✅ Yes
x86 (IA32) [^1]    | ✅ Yes   | ✅ Yes      | 🟨 Probably | ⬜️ *N/A* | ✅ Yes      | ✅ Yes      | ⬜️ *N/A*
ARM32 LE [^2]      | ⬜️ *N/A* | ✅ Yes      | 🟨 Probably | ⬜️ *N/A* | 🟨 Probably | 🟨 Probably | 🟨 Probably
RISC-V 64 [^3]     | ⬜️ *N/A* | ✅ Yes      | 🟨 Probably | ⬜️ *N/A* | 🟨 Probably | 🟨 Probably | ⬜️ *N/A*
LoongArch64        | ⬜️ *N/A* | ✅ Yes      | 🟨 Probably | ⬜️ *N/A* | 🟨 Probably | 🟨 Probably | ⬜️ *N/A*
PowerPC 64 LE [^4] | ⬜️ *N/A* | ✅ Yes      | 🟨 Probably | ⬜️ *N/A* | 🟨 Probably | 🟨 Probably | ⬜️ *N/A*

[^1]: The following call conventions are supported: cdecl, stdcall, MS fastcall, thiscall.
[^2]: The prebuilt binary uses the hard float ABI and expects a VFP coprocessor. Build from source to use Koffi with a different ABI (softfp, soft).
[^3]: The prebuilt binary uses the LP64D (double-precision float) ABI. The LP64 ABI is supported in theory if you build Koffi from source but this is untested. The LP64F ABI is not supported.
[^4]: Only the ELFv2 Power64 Little Endian ABI is supported for now.

Go to the web site for more information: https://koffi.dev/

# Project history

You can consult the [changelog](https://koffi.dev/changelog) on the official website.

Major version increments can include breaking API changes, use the [migration guide](https://koffi.dev/changelog#migration-guide) for more information.

# Build manually

Koffi is built with a custom CMake-wrapper called CNoke, which also lives in this repository. Don't try to run CMake manually because it will fail.

Follow the [documented build instructions](https://koffi.dev/contribute#build-from-source) to build Koffi from source.

# License

This program is free software: you can redistribute it and/or modify it under the terms of the **MIT License**.

Find more information here: https://choosealicense.com/licenses/mit/

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_Source: https://npm.io/package/koffi · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._