diff --git a/src/main.cpp b/src/main.cpp
index 16b1cf9..08ca273 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -54,6 +54,8 @@ Subcommands:
   rollback                Show available generations
   index        <dir>      Build an index.kap from .kap files in a directory
   add          <pkg> [v]  Add a package to system config (optional version)
+                  --features "key=on,key2=off"   Set feature flags
+                  --config   "key=val,key2=val2" Set config values
   remove       <pkg>      Remove a package from system config
 
 Options:
@@ -232,6 +234,8 @@ int main(int argc, char* argv[]) {
 
     const char* file_arg = nullptr;
     const char* version_arg = nullptr;
+    const char* features_arg = nullptr;
+    const char* config_arg = nullptr;
     bool dry_run = false;
     for (int i = arg_start + 1; i < argc; ++i) {
         if (std::string_view(argv[i]) == "-h"
@@ -254,6 +258,14 @@ int main(int argc, char* argv[]) {
             paths::set_root(argv[++i]);
             continue;
         }
+        if (std::string_view(argv[i]) == "--features" && i + 1 < argc) {
+            features_arg = argv[++i];
+            continue;
+        }
+        if (std::string_view(argv[i]) == "--config" && i + 1 < argc) {
+            config_arg = argv[++i];
+            continue;
+        }
         if (std::string_view(argv[i]) == "--dry-run") {
             dry_run = true;
             continue;
@@ -334,6 +346,52 @@ int main(int argc, char* argv[]) {
             std::cerr << "error: no package name specified\n";
             return 1;
         }
+
+        // Parse --features key=on,key2=off
+        std::unordered_map<std::string, dsl::FeatureDef> features;
+        if (features_arg != nullptr) {
+            std::string_view fsv(features_arg);
+            std::size_t pos = 0;
+            while (pos < fsv.size()) {
+                auto comma = fsv.find(',', pos);
+                auto pair = fsv.substr(pos, comma == std::string_view::npos
+                                             ? std::string_view::npos
+                                             : comma - pos);
+                auto eq = pair.find('=');
+                if (eq != std::string_view::npos) {
+                    auto key = std::string(pair.substr(0, eq));
+                    auto val = pair.substr(eq + 1);
+                    while (!key.empty() && key.back() == ' ') key.pop_back();
+                    while (!val.empty() && val.front() == ' ') val.remove_prefix(1);
+                    features[key] = {val == "on" || val == "true" || val == "1",
+                                     false, ""};
+                }
+                pos = comma == std::string_view::npos ? fsv.size() : comma + 1;
+            }
+        }
+
+        // Parse --config key=val,key2=val2
+        std::unordered_map<std::string, std::string> config;
+        if (config_arg != nullptr) {
+            std::string_view csv(config_arg);
+            std::size_t pos = 0;
+            while (pos < csv.size()) {
+                auto comma = csv.find(',', pos);
+                auto pair = csv.substr(pos, comma == std::string_view::npos
+                                             ? std::string_view::npos
+                                             : comma - pos);
+                auto eq = pair.find('=');
+                if (eq != std::string_view::npos) {
+                    auto key = std::string(pair.substr(0, eq));
+                    auto val = std::string(pair.substr(eq + 1));
+                    while (!key.empty() && key.back() == ' ') key.pop_back();
+                    while (!val.empty() && val.front() == ' ') val.erase(0, 1);
+                    config[key] = val;
+                }
+                pos = comma == std::string_view::npos ? csv.size() : comma + 1;
+            }
+        }
+
         try {
             auto config_path = std::filesystem::path(paths::system_dir()) / "config.kap";
             dsl::SystemConfig cfg;
@@ -347,10 +405,21 @@ int main(int argc, char* argv[]) {
             for (auto& p : cfg.packages) {
                 if (p.name == file_arg) {
                     found = true;
+                    bool changed = false;
                     if (version_arg != nullptr) {
                         p.version = version_arg;
-                        std::cout << "updated " << file_arg
-                                  << " → version " << version_arg << "\n";
+                        changed = true;
+                    }
+                    if (!features.empty()) {
+                        for (auto& [k, v] : features) { p.features[k] = v; changed = true; }
+                    }
+                    if (!config.empty()) {
+                        for (auto& [k, v] : config) { p.config[k] = v; changed = true; }
+                    }
+                    if (changed) {
+                        std::cout << "updated " << file_arg;
+                        if (version_arg != nullptr) std::cout << " → " << version_arg;
+                        std::cout << "\n";
                     } else {
                         std::cout << file_arg << " already in packages\n";
                     }
@@ -364,11 +433,11 @@ int main(int argc, char* argv[]) {
                 if (version_arg != nullptr) {
                     pref.version = version_arg;
                 }
+                pref.features = std::move(features);
+                pref.config = std::move(config);
                 cfg.packages.push_back(std::move(pref));
                 std::cout << "added " << file_arg;
-                if (version_arg != nullptr) {
-                    std::cout << " " << version_arg;
-                }
+                if (version_arg != nullptr) std::cout << " " << version_arg;
                 std::cout << "\n";
             }