Add .github/releases.json with release channels and update install.sh with channel-based version resolution

.github/releases.json

@@ -0,0 +1,16 @@
+{
+  "channels": {
+    "stable": {
+      "version": "v0.57.2",
+      "engines": {
+        "copilot": "latest"
+      }
+    },
+    "latest": {
+      "version": "latest",
+      "engines": {
+        "copilot": "latest"
+      }
+    }
+  }
+}

install-gh-aw.sh

@@ -2,13 +2,17 @@
 
 # Script to download and install gh-aw binary for the current OS and architecture
 # Supports: Linux, macOS (Darwin), FreeBSD, Windows (Git Bash/MSYS/Cygwin)
-# Usage: ./install-gh-aw.sh [version] [options]
-# If no version is specified, it will use "latest" (GitHub automatically resolves to the latest release)
+# Usage: ./install-gh-aw.sh [version|channel] [options]
+# If no version is specified, it will resolve the "stable" channel from .github/releases.json
+# A semver version (e.g. v1.0.0) is used directly; a channel name (e.g. "stable", "latest")
+# is resolved via .github/releases.json fetched from the raw GitHub URL (no token required).
 # Note: Checksum validation is currently skipped by default (will be enabled in future releases)
 # 
 # Examples:
-#   ./install-gh-aw.sh                           # Install latest version
-#   ./install-gh-aw.sh v1.0.0                    # Install specific version
+#   ./install-gh-aw.sh                           # Install stable channel (default)
+#   ./install-gh-aw.sh stable                    # Install stable channel explicitly
+#   ./install-gh-aw.sh latest                    # Install latest channel
+#   ./install-gh-aw.sh v1.0.0                    # Install specific semver version directly
 #   ./install-gh-aw.sh --skip-checksum           # Skip checksum validation
 #
 # Options:
@@ -224,15 +228,71 @@ fetch_release_data() {
     return 1
 }
 
-# Get version (use provided version or default to "latest")
+# Get version (use provided version/channel, or default to "stable" channel)
 # VERSION is already set from argument parsing
 REPO="github/gh-aw"
+RELEASES_JSON_URL="https://raw.githubusercontent.com/$REPO/main/.github/releases.json"
+DEFAULT_CHANNEL="stable"
+
+# Resolve a channel name to a version using the releases.json config file.
+# The file is fetched from the raw GitHub URL without authentication.
+resolve_channel_version() {
+    local channel=$1
+    print_info "Resolving version for channel '$channel' from releases config..." >&2
+
+    local releases_data
+    releases_data=$(curl -sf "$RELEASES_JSON_URL" 2>/dev/null)
+    local curl_exit=$?
+
+    if [ $curl_exit -ne 0 ] || [ -z "$releases_data" ]; then
+        print_warning "Failed to fetch releases config from $RELEASES_JSON_URL" >&2
+        return 1
+    fi
+
+    local version=""
+    if [ "$HAS_JQ" = true ]; then
+        version=$(echo "$releases_data" | jq -r ".channels[\"$channel\"].version // empty" 2>/dev/null)
+    elif command -v python3 &>/dev/null; then
+        version=$(echo "$releases_data" | python3 -c "import sys,json; d=json.load(sys.stdin); print(d.get('channels',{}).get('$channel',{}).get('version',''))" 2>/dev/null)
+    elif command -v python &>/dev/null; then
+        version=$(echo "$releases_data" | python -c "import sys,json; d=json.load(sys.stdin); print(d.get('channels',{}).get('$channel',{}).get('version',''))" 2>/dev/null)
+    else
+        # Grep/awk fallback: find the channel block and extract its version field
+        version=$(echo "$releases_data" | grep -A 10 "\"$channel\":" | grep '"version":' | head -1 | sed 's/.*"version": *"\([^"]*\)".*/\1/')
+    fi
+
+    if [ -z "$version" ]; then
+        print_warning "Channel '$channel' not found in releases config" >&2
+        return 1
+    fi
+
+    echo "$version"
+    return 0
+}
 
 if [ -z "$VERSION" ]; then
-    print_info "No version specified, using 'latest'..."
-    VERSION="latest"
-else
+    print_info "No version specified, resolving from '$DEFAULT_CHANNEL' channel..."
+    resolved=$(resolve_channel_version "$DEFAULT_CHANNEL")
+    if [ $? -eq 0 ] && [ -n "$resolved" ]; then
+        VERSION="$resolved"
+        print_info "Resolved version: $VERSION (from '$DEFAULT_CHANNEL' channel)"
+    else
+        print_warning "Failed to resolve '$DEFAULT_CHANNEL' channel, falling back to 'latest'..."
+        VERSION="latest"
+    fi
+elif [[ "$VERSION" =~ ^v[0-9]+\.[0-9]+\.[0-9]+ ]]; then
+    # Semver detected (no end anchor so pre-release suffixes like -beta.1 also match)
     print_info "Using specified version: $VERSION"
+else
+    print_info "Resolving version from channel '$VERSION'..."
+    resolved=$(resolve_channel_version "$VERSION")
+    if [ $? -eq 0 ] && [ -n "$resolved" ]; then
+        print_info "Resolved version: $resolved (from '$VERSION' channel)"
+        VERSION="$resolved"
+    else
+        print_warning "Failed to resolve channel '$VERSION'. Trying as direct version..."
+        print_info "Using: $VERSION"
+    fi
 fi
 
 # Try gh extension install if requested (and gh is available)

pkg/cli/setup_cli_action_integration_test.go

@@ -42,17 +42,21 @@ func TestSetupCLIAction(t *testing.T) {
 		}
 	})
 
-	// Test that script can fetch latest version when INPUT_VERSION is not provided
-	t.Run("can_fetch_latest_without_input_version", func(t *testing.T) {
-		// This test would actually try to fetch from GitHub API
-		// We just verify the script doesn't immediately fail
+	// Test that script resolves "stable" channel by default when INPUT_VERSION is not provided
+	t.Run("defaults_to_stable_channel", func(t *testing.T) {
+		// This test would actually try to fetch from GitHub
+		// We just verify the script has the correct default channel logic
 		content, err := os.ReadFile(installScript)
 		if err != nil {
 			t.Fatalf("Failed to read install.sh: %v", err)
 		}
-		// Verify script has fallback to fetch latest
-		if !strings.Contains(string(content), "No version specified") || !strings.Contains(string(content), "using 'latest'") {
-			t.Errorf("Script should support fetching latest release when no version is provided")
+		// Verify script defaults to "stable" channel
+		if !strings.Contains(string(content), `DEFAULT_CHANNEL="stable"`) {
+			t.Errorf("Script should default to 'stable' channel when no version is provided")
+		}
+		// Verify script has channel resolution function
+		if !strings.Contains(string(content), "resolve_channel_version") {
+			t.Errorf("Script should have resolve_channel_version function")
 		}
 	})
 

scripts/test-install-script.sh

@@ -351,19 +351,51 @@ else
     exit 1
 fi
 
-# Test 11: Verify "latest" version functionality
+# Test 11: Verify channel-based version resolution
 echo ""
-echo "Test 11: Verify 'latest' version functionality"
+echo "Test 11: Verify channel-based version resolution"
 
-# Check for "latest" as default version
-if grep -q "using 'latest'" "$PROJECT_ROOT/install-gh-aw.sh"; then
-    echo "  ✓ PASS: Script uses 'latest' as default version"
+# Check for DEFAULT_CHANNEL variable set to "stable"
+if grep -q 'DEFAULT_CHANNEL="stable"' "$PROJECT_ROOT/install-gh-aw.sh"; then
+    echo "  ✓ PASS: Script defaults to 'stable' channel"
 else
-    echo "  ✗ FAIL: Script does not use 'latest' as default version"
+    echo "  ✗ FAIL: Script does not default to 'stable' channel"
     exit 1
 fi
 
-# Check for latest URL construction
+# Check for resolve_channel_version function
+if grep -q "resolve_channel_version()" "$PROJECT_ROOT/install-gh-aw.sh"; then
+    echo "  ✓ PASS: resolve_channel_version function exists"
+else
+    echo "  ✗ FAIL: resolve_channel_version function not found"
+    exit 1
+fi
+
+# Check for RELEASES_JSON_URL variable
+if grep -q 'RELEASES_JSON_URL=' "$PROJECT_ROOT/install-gh-aw.sh"; then
+    echo "  ✓ PASS: RELEASES_JSON_URL variable exists"
+else
+    echo "  ✗ FAIL: RELEASES_JSON_URL variable not found"
+    exit 1
+fi
+
+# Check that releases.json URL uses raw.githubusercontent.com (no token required)
+if grep -q 'raw.githubusercontent.com' "$PROJECT_ROOT/install-gh-aw.sh"; then
+    echo "  ✓ PASS: Releases config fetched from raw.githubusercontent.com (no token)"
+else
+    echo "  ✗ FAIL: Releases config URL not using raw.githubusercontent.com"
+    exit 1
+fi
+
+# Check for semver detection logic (bash regex: ^v[0-9]+\.[0-9]+\.[0-9]+)
+if grep -qF '^v[0-9]+\.[0-9]+\.[0-9]+' "$PROJECT_ROOT/install-gh-aw.sh"; then
+    echo "  ✓ PASS: Semver detection regex exists"
+else
+    echo "  ✗ FAIL: Semver detection regex not found"
+    exit 1
+fi
+
+# Check for latest URL construction (still needed for "latest" channel)
 if grep -q 'releases/latest/download' "$PROJECT_ROOT/install-gh-aw.sh"; then
     echo "  ✓ PASS: Latest release URL pattern is correct"
 else