diff --git a/TODO-4.2.1.md b/TODO-4.2.1.md
index d1c2923..544e9e9 100644
--- a/TODO-4.2.1.md
+++ b/TODO-4.2.1.md
@@ -29,7 +29,11 @@
   - Created aur-cli/PKGBUILD with [cli,dct,compression] extras only
   - No flask/gunicorn/fastapi/uvicorn/pyzbar deps
   - 68MB vs 79MB for full package
-- [ ] `stegasoo-api` - REST API package (needs auth overhaul first)
+- [x] `stegasoo-api` - REST API package
+  - Created aur-api/PKGBUILD with [api,cli,compression] extras
+  - Has fastapi/uvicorn, no flask/gunicorn
+  - 74MB package size
+  - Includes systemd service with TLS
 
 ## API Auth Work
 - [x] API key authentication (simpler than OAuth2 for personal use)
@@ -47,5 +51,4 @@
   - `stegasoo api serve` (starts with TLS by default)
 
 ## API Documentation
-- [ ] Postman collection
-- [ ] Environment variable templates
+- [ ] Postman collection (with environment templates)
diff --git a/aur-api/.SRCINFO b/aur-api/.SRCINFO
new file mode 100644
index 0000000..909a66f
--- /dev/null
+++ b/aur-api/.SRCINFO
@@ -0,0 +1,23 @@
+pkgbase = stegasoo-api-git
+	pkgdesc = Stegasoo REST API with TLS and API key authentication
+	pkgver = 4.2.0.r6.g34ede38
+	pkgrel = 1
+	url = https://github.com/adlee-was-taken/stegasoo
+	install = stegasoo-api-git.install
+	arch = x86_64
+	license = MIT
+	makedepends = git
+	makedepends = python
+	makedepends = python-build
+	makedepends = python-hatchling
+	depends = python>=3.11
+	depends = zbar
+	optdepends = libjpeg-turbo: jpegtran for lossless JPEG rotation (DCT-safe)
+	provides = stegasoo-api
+	conflicts = stegasoo-api
+	conflicts = stegasoo
+	conflicts = stegasoo-git
+	source = stegasoo-api-git::git+https://github.com/adlee-was-taken/stegasoo.git#branch=main
+	sha256sums = SKIP
+
+pkgname = stegasoo-api-git
diff --git a/aur-api/PKGBUILD b/aur-api/PKGBUILD
new file mode 100644
index 0000000..a4f23d6
--- /dev/null
+++ b/aur-api/PKGBUILD
@@ -0,0 +1,109 @@
+# Maintainer: Aaron D. Lee <your-email@example.com>
+pkgname=stegasoo-api-git
+pkgver=4.2.0.r6.g34ede38
+pkgrel=1
+pkgdesc="Stegasoo REST API with TLS and API key authentication"
+arch=('x86_64')
+url="https://github.com/adlee-was-taken/stegasoo"
+license=('MIT')
+
+# Python 3.11-3.14 supported
+depends=(
+    'python>=3.11'
+    'zbar'  # QR code reading for RSA key extraction
+)
+makedepends=(
+    'git'
+    'python'
+    'python-build'
+    'python-hatchling'
+)
+optdepends=(
+    'libjpeg-turbo: jpegtran for lossless JPEG rotation (DCT-safe)'
+)
+provides=('stegasoo-api')
+conflicts=('stegasoo-api' 'stegasoo' 'stegasoo-git')
+install=stegasoo-api-git.install
+source=("${pkgname}::git+https://github.com/adlee-was-taken/stegasoo.git#branch=main")
+sha256sums=('SKIP')
+
+pkgver() {
+    cd "$pkgname"
+    git describe --long --tags 2>/dev/null | sed 's/^v//;s/\([^-]*-g\)/r\1/;s/-/./g' || \
+    printf "%s.r%s.g%s" "4.2.1" "$(git rev-list --count HEAD)" "$(git rev-parse --short HEAD)"
+}
+
+build() {
+    cd "$pkgname"
+    python -m build --wheel --no-isolation
+}
+
+package() {
+    cd "$pkgname"
+
+    # Detect Python version for site-packages path
+    local pyver=$(python -c 'import sys; print(f"{sys.version_info.major}.{sys.version_info.minor}")')
+
+    # Install to /opt/stegasoo-api with dedicated venv
+    install -dm755 "$pkgdir/opt/stegasoo-api"
+
+    # Create fresh venv in package
+    python -m venv "$pkgdir/opt/stegasoo-api/venv"
+
+    # Install the wheel with API + CLI + compression extras
+    local wheel=$(ls dist/*.whl | head -1)
+    "$pkgdir/opt/stegasoo-api/venv/bin/pip" install --no-cache-dir "${wheel}[api,cli,compression]"
+
+    # Install API frontend (not included in wheel by default)
+    local site_packages="$pkgdir/opt/stegasoo-api/venv/lib/python${pyver}/site-packages"
+    install -dm755 "$site_packages/frontends/api"
+    cp -r frontends/api/*.py "$site_packages/frontends/api/"
+    cp -r frontends/__init__.py "$site_packages/frontends/" 2>/dev/null || true
+
+    # Create temp directory for API
+    install -dm755 "$site_packages/frontends/api/temp_files"
+
+    # Create config directories
+    install -dm755 "$pkgdir/opt/stegasoo-api/config"
+    install -dm700 "$pkgdir/opt/stegasoo-api/certs"
+
+    # Fix shebangs - replace build-time paths with installed paths
+    find "$pkgdir/opt/stegasoo-api/venv/bin" -type f -exec \
+        sed -i "s|$pkgdir/opt/stegasoo-api/venv|/opt/stegasoo-api/venv|g" {} \;
+
+    # Fix pyvenv.cfg
+    sed -i "s|$pkgdir||g" "$pkgdir/opt/stegasoo-api/venv/pyvenv.cfg"
+
+    # Create symlink to /usr/bin
+    install -dm755 "$pkgdir/usr/bin"
+    ln -s /opt/stegasoo-api/venv/bin/stegasoo "$pkgdir/usr/bin/stegasoo"
+
+    # Install license
+    install -Dm644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+
+    # Install docs
+    install -Dm644 README.md "$pkgdir/usr/share/doc/$pkgname/README.md"
+
+    # Install systemd service
+    install -Dm644 /dev/stdin "$pkgdir/usr/lib/systemd/system/stegasoo-api.service" <<EOF
+[Unit]
+Description=Stegasoo REST API (HTTPS)
+After=network.target
+
+[Service]
+Type=simple
+User=stegasoo
+WorkingDirectory=/opt/stegasoo-api/venv/lib/python${pyver}/site-packages/frontends/api
+Environment="PATH=/opt/stegasoo-api/venv/bin"
+Environment="HOME=/opt/stegasoo-api"
+# TLS enabled by default - certs auto-generated on first run
+# Use: stegasoo api tls generate (to pre-generate certs)
+# Use: stegasoo api keys create <name> (to create API keys)
+ExecStart=/opt/stegasoo-api/venv/bin/stegasoo api serve --host 127.0.0.1 --port 8000
+Restart=on-failure
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target
+EOF
+}
diff --git a/aur-api/stegasoo-api-git.install b/aur-api/stegasoo-api-git.install
new file mode 100644
index 0000000..99271e6
--- /dev/null
+++ b/aur-api/stegasoo-api-git.install
@@ -0,0 +1,48 @@
+post_install() {
+    # Create stegasoo system user if it doesn't exist
+    if ! getent passwd stegasoo >/dev/null; then
+        useradd -r -s /usr/bin/nologin -d /opt/stegasoo-api stegasoo
+        echo "Created system user 'stegasoo'"
+    fi
+
+    # Set ownership of directories
+    chown -R stegasoo:stegasoo /opt/stegasoo-api/config 2>/dev/null || true
+    chown -R stegasoo:stegasoo /opt/stegasoo-api/certs 2>/dev/null || true
+
+    echo ""
+    echo "Stegasoo API installed successfully!"
+    echo ""
+    echo "Quick Start:"
+    echo "  1. Create an API key:"
+    echo "     stegasoo api keys create mykey"
+    echo ""
+    echo "  2. Start the API server:"
+    echo "     sudo systemctl start stegasoo-api"
+    echo ""
+    echo "  3. Access the API:"
+    echo "     curl -k -H 'X-API-Key: YOUR_KEY' https://localhost:8000/"
+    echo ""
+    echo "Management commands:"
+    echo "  stegasoo api keys list       # List API keys"
+    echo "  stegasoo api keys create X   # Create new key"
+    echo "  stegasoo api tls info        # Show certificate info"
+    echo "  stegasoo api serve --help    # Server options"
+    echo ""
+    echo "API docs available at: https://localhost:8000/docs"
+    echo ""
+}
+
+post_upgrade() {
+    post_install
+}
+
+pre_remove() {
+    # Stop service if running
+    systemctl stop stegasoo-api 2>/dev/null || true
+}
+
+post_remove() {
+    echo "Stegasoo API removed."
+    echo "User 'stegasoo' and config in /opt/stegasoo-api were not removed."
+    echo "To remove: userdel stegasoo && rm -rf /opt/stegasoo-api"
+}
diff --git a/aur-api/test-build.sh b/aur-api/test-build.sh
new file mode 100755
index 0000000..74f361e
--- /dev/null
+++ b/aur-api/test-build.sh
@@ -0,0 +1,22 @@
+#!/bin/bash
+# Test build the AUR API package locally
+
+set -e
+
+cd "$(dirname "$0")"
+
+echo "=== Cleaning previous builds ==="
+rm -rf stegasoo-api-git pkg src *.pkg.tar.zst *.whl 2>/dev/null || true
+
+echo "=== Generating .SRCINFO ==="
+makepkg --printsrcinfo > .SRCINFO
+
+echo "=== Building package ==="
+makepkg -sf
+
+echo "=== Package built ==="
+ls -la *.pkg.tar.zst
+
+echo ""
+echo "To install: sudo pacman -U stegasoo-api-git-*.pkg.tar.zst"
+echo "To test:    makepkg -si"