diff --git a/.github/workflows/appstore-build-publish.yml b/.github/workflows/appstore-build-publish.yml
index 63b20f0..bd1165d 100644
--- a/.github/workflows/appstore-build-publish.yml
+++ b/.github/workflows/appstore-build-publish.yml
@@ -11,6 +11,8 @@ env:
 jobs:
   build-and-publish:
     runs-on: ubuntu-latest
+    # Only run on Astrolabe releases
+    if: startsWith(github.ref, 'refs/tags/astrolabe-v')
 
     steps:
       - name: Checkout code
@@ -19,7 +21,7 @@ jobs:
       - name: Get version from tag
         id: tag
         run: |
-          echo "TAG=${GITHUB_REF#refs/tags/v}" >> $GITHUB_OUTPUT
+          echo "TAG=${GITHUB_REF#refs/tags/astrolabe-v}" >> $GITHUB_OUTPUT
 
       - name: Validate version in info.xml matches tag
         working-directory: ${{ env.APP_DIR }}
diff --git a/scripts/bump-astrolabe.sh b/scripts/bump-astrolabe.sh
index 79e61cc..4a320d7 100755
--- a/scripts/bump-astrolabe.sh
+++ b/scripts/bump-astrolabe.sh
@@ -2,6 +2,9 @@
 # Bump Astrolabe app version
 set -e
 
+# Validate dependencies
+command -v uv >/dev/null 2>&1 || { echo "Error: uv not found. Install from https://docs.astral.sh/uv/"; exit 1; }
+
 cd third_party/astrolabe
 
 echo "Bumping Astrolabe version..."
diff --git a/scripts/bump-helm.sh b/scripts/bump-helm.sh
index 75d08e7..dd5411a 100755
--- a/scripts/bump-helm.sh
+++ b/scripts/bump-helm.sh
@@ -2,6 +2,9 @@
 # Bump Helm chart version
 set -e
 
+# Validate dependencies
+command -v uv >/dev/null 2>&1 || { echo "Error: uv not found. Install from https://docs.astral.sh/uv/"; exit 1; }
+
 cd charts/nextcloud-mcp-server
 
 echo "Bumping Helm chart version..."
diff --git a/scripts/bump-mcp.sh b/scripts/bump-mcp.sh
index 29bb045..6cc9a47 100755
--- a/scripts/bump-mcp.sh
+++ b/scripts/bump-mcp.sh
@@ -2,6 +2,9 @@
 # Bump MCP server version
 set -e
 
+# Validate dependencies
+command -v uv >/dev/null 2>&1 || { echo "Error: uv not found. Install from https://docs.astral.sh/uv/"; exit 1; }
+
 echo "Bumping MCP server version..."
 uv run cz bump --yes
 
diff --git a/third_party/astrolabe/Makefile b/third_party/astrolabe/Makefile
index bf9f188..f96e6e0 100644
--- a/third_party/astrolabe/Makefile
+++ b/third_party/astrolabe/Makefile
@@ -9,19 +9,31 @@ appstore_dir=$(build_dir)/artifacts
 package_name=$(appstore_dir)/$(app_name)
 cert_dir=$(HOME)/.nextcloud/certificates
 
+# Nextcloud server path (configurable via environment variable)
+server_dir?=../../server
+occ=$(server_dir)/occ
+
 # Signing
 private_key=$(cert_dir)/$(app_name).key
 certificate=$(cert_dir)/$(app_name).crt
-sign_cmd=php ../../server/occ integrity:sign-app --privateKey=$(private_key) --certificate=$(certificate)
+sign_cmd=php $(occ) integrity:sign-app --privateKey=$(private_key) --certificate=$(certificate)
 
 # Clean build artifacts
 .PHONY: clean
 clean:
 	rm -rf $(build_dir)
 
+# Validate required dependencies
+.PHONY: validate-deps
+validate-deps:
+	@command -v composer >/dev/null 2>&1 || { echo "Error: composer not found. Install from https://getcomposer.org/"; exit 1; }
+	@command -v npm >/dev/null 2>&1 || { echo "Error: npm not found. Install Node.js from https://nodejs.org/"; exit 1; }
+	@command -v php >/dev/null 2>&1 || { echo "Error: php not found. Install PHP 8.1 or higher."; exit 1; }
+	@echo "✓ All dependencies found"
+
 # Install PHP and Node dependencies
 .PHONY: install-deps
-install-deps:
+install-deps: validate-deps
 	composer install --no-dev --optimize-autoloader
 	npm ci
 
@@ -63,9 +75,17 @@ assemble: clean install-deps build-frontend
 		--exclude='src/' \
 		./ $(package_name)/
 
+# Validate signing prerequisites
+.PHONY: validate-signing
+validate-signing:
+	@test -f $(occ) || { echo "Error: Nextcloud server not found at $(server_dir)"; echo "Set server_dir variable: make appstore server_dir=/path/to/server"; exit 1; }
+	@test -f $(private_key) || { echo "Error: Private key not found at $(private_key)"; exit 1; }
+	@test -f $(certificate) || { echo "Error: Certificate not found at $(certificate)"; exit 1; }
+	@echo "✓ Signing prerequisites validated"
+
 # Create signed release tarball for App Store
 .PHONY: appstore
-appstore: assemble
+appstore: assemble validate-signing
 	# Sign the app
 	$(sign_cmd) --path=$(package_name)
 	# Create tarball