diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index d5d4be51..d35cf596 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Externalized koffi from bun binary builds, reducing archive sizes by ~15MB per platform (e.g. darwin-arm64: 43MB -> 28MB). Koffi's Windows-only `.node` file is now shipped alongside the Windows binary only.
+
 ## [0.54.0] - 2026-02-19
 
 ### Added
diff --git a/packages/tui/CHANGELOG.md b/packages/tui/CHANGELOG.md
index 903312f6..bcc556d1 100644
--- a/packages/tui/CHANGELOG.md
+++ b/packages/tui/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Changed koffi import from top-level to dynamic require in `enableWindowsVTInput()` to prevent bun from embedding all 18 platform `.node` files (~74MB) into every compiled binary. Koffi is only needed on Windows.
+
 ## [0.54.0] - 2026-02-19
 
 ## [0.53.1] - 2026-02-19
diff --git a/packages/tui/src/terminal.ts b/packages/tui/src/terminal.ts
index 5a83d876..52f6361c 100644
--- a/packages/tui/src/terminal.ts
+++ b/packages/tui/src/terminal.ts
@@ -1,5 +1,4 @@
 import * as fs from "node:fs";
-import koffi from "koffi";
 import { setKittyProtocolActive } from "./keys.js";
 import { StdinBuffer } from "./stdin-buffer.js";
 
@@ -174,6 +173,10 @@ export class ProcessTerminal implements Terminal {
 	private enableWindowsVTInput(): void {
 		if (process.platform !== "win32") return;
 		try {
+			// Dynamic require to avoid bundling koffi's 74MB of cross-platform
+			// native binaries into every compiled binary. Koffi is only needed
+			// on Windows for VT input support.
+			const koffi = require("koffi");
 			const k32 = koffi.load("kernel32.dll");
 			const GetStdHandle = k32.func("void* __stdcall GetStdHandle(int)");
 			const GetConsoleMode = k32.func("bool __stdcall GetConsoleMode(void*, _Out_ uint32_t*)");
diff --git a/scripts/build-binaries.sh b/scripts/build-binaries.sh
index 0488c8cf..fd9a60f5 100755
--- a/scripts/build-binaries.sh
+++ b/scripts/build-binaries.sh
@@ -102,10 +102,14 @@ fi
 
 for platform in "${PLATFORMS[@]}"; do
     echo "Building for $platform..."
+    # Externalize koffi to avoid embedding all 18 platform .node files (~74MB)
+    # into every binary. Koffi is only used on Windows for VT input and the
+    # call site has a try/catch fallback. For Windows builds, we copy the
+    # appropriate .node file alongside the binary below.
     if [[ "$platform" == "windows-x64" ]]; then
-        bun build --compile --target=bun-$platform ./dist/cli.js --outfile binaries/$platform/pi.exe
+        bun build --compile --external koffi --target=bun-$platform ./dist/cli.js --outfile binaries/$platform/pi.exe
     else
-        bun build --compile --target=bun-$platform ./dist/cli.js --outfile binaries/$platform/pi
+        bun build --compile --external koffi --target=bun-$platform ./dist/cli.js --outfile binaries/$platform/pi
     fi
 done
 
@@ -122,6 +126,14 @@ for platform in "${PLATFORMS[@]}"; do
     cp -r dist/core/export-html binaries/$platform/
     cp -r docs binaries/$platform/
     cp -r examples binaries/$platform/
+
+    # Copy koffi native module for Windows (needed for VT input support)
+    if [[ "$platform" == "windows-x64" ]]; then
+        mkdir -p binaries/$platform/node_modules/koffi/build/koffi/win32_x64
+        cp ../../node_modules/koffi/index.js binaries/$platform/node_modules/koffi/
+        cp ../../node_modules/koffi/package.json binaries/$platform/node_modules/koffi/
+        cp ../../node_modules/koffi/build/koffi/win32_x64/koffi.node binaries/$platform/node_modules/koffi/build/koffi/win32_x64/
+    fi
 done
 
 # Create archives