@tsdrivers/mssql

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Runtime Support ​

The @tsdrivers/mssql package includes FFI adapters for all three supported runtimes. The correct adapter is selected automatically — no configuration needed.

How It Works ​

When you first call createPool() or connect(), the package:

  1. Detects the runtime (Deno, Bun, or Node.js)
  2. Loads the correct FFI adapter (Deno.dlopen or koffi)
  3. Resolves the native library using the standard search order
  4. Caches the result — subsequent calls reuse the same FFI singleton

Deno ​

FFI initialization starts eagerly at module evaluation time. Since Deno's dlopen is synchronous, the FFI is typically ready before your code calls createPool() or connect().

Node.js ​

Uses koffi for FFI binding with nonblocking async calls via worker threads. Install alongside the package:

sh
npm install @tsdrivers/mssql koffi

Bun ​

Also uses koffi for nonblocking async FFI support (Bun's built-in bun:ffi does not support async calls). Install alongside the package:

sh
bun add @tsdrivers/mssql koffi

Low-Level FFI Access ​

The package exports getFfi() and loadLibrary() for advanced use cases:

ts
import { getFfi, loadLibrary } from "@tsdrivers/mssql";

// Get the FFI singleton (resolved lazily, or eagerly on Deno)
const ffi = await getFfi();

// Or load from an explicit path
const ffi = await loadLibrary("/path/to/mssqlts-linux-x86_64.so");

// Check FILESTREAM availability (Windows only)
if (ffi.filestreamAvailable()) {
  console.log("FILESTREAM is available");
}