@bun-win32/wevtapi

Zero-dependency, zero-overhead Win32 Wevtapi bindings for Bun on Windows.

Overview

@bun-win32/wevtapi exposes the wevtapi.dll exports using Bun's FFI. It provides a single class, Wevtapi, which lazily binds native symbols on first use. You can optionally preload a subset or all symbols up-front via Preload().

The bindings are strongly typed for a smooth DX in TypeScript.

Features

• Bun-first ergonomics on Windows 10/11.
• Direct FFI to wevtapi.dll (Windows Event Log queries, rendering, subscriptions, channel configuration, and publisher metadata).
• In-source docs in structs/Wevtapi.ts with links to Microsoft Learn.
• Lazy binding on first call; optional eager preload (Wevtapi.Preload()).
• No wrapper overhead; calls map 1:1 to native APIs.
• Strongly-typed Win32 aliases, enums, and constants (see types/Wevtapi.ts).

Requirements

• Bun runtime
• Windows 10 or later

Installation

bun add @bun-win32/wevtapi

Quick Start

import Wevtapi, { EvtQueryFlags } from '@bun-win32/wevtapi';

const channelPath = Buffer.from('System\0', 'utf16le');
const query = Buffer.from('*\0', 'utf16le');
const resultSet = Wevtapi.EvtQuery(0n, channelPath.ptr, query.ptr, EvtQueryFlags.EvtQueryChannelPath);

if (resultSet === 0n) {
  throw new Error('EvtQuery failed');
}

Wevtapi.EvtClose(resultSet);

[!NOTE] AI agents: see AI.md for the package binding contract and source-navigation guidance. It explains how to use the package without scanning the entire implementation.

Examples

Run the included examples:

bun run example:event-tail
bun run example:channel-report

Notes

• Either rely on lazy binding or call Wevtapi.Preload().
• Windows only. Bun runtime required.
• SAL types & naming: nullability is in the type — Optional<T> (formally optional, SAL _*opt_) and Nullable<T> (plain [in]/[out] the docs say can be NULL), the null sentinel derived from T (null for pointers LP*/P*, 0n for handles/by-value addresses); direction is in the parameter name — _out (_Out_), _in_out (_Inout_), _In_ bare. See AI.md and the repo AGENTS.md.