diff --git a/CMakeLists.txt b/CMakeLists.txt
index f934439..e517d5f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,6 +23,8 @@ set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
+find_package(Threads REQUIRED)
+
 # Helper target for common warnings
 add_library(project_options INTERFACE)
 if(MSVC)
@@ -49,14 +51,18 @@ endif()
 set(SRC_FILES
     src/main.cpp
     src/media_server_app.cpp
+    src/graph_manager.cpp
+    src/plugin_loader.cpp
 )
 
 add_executable(media-server ${SRC_FILES})
+set_target_properties(media-server PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
 target_include_directories(media-server
     PRIVATE
         ${CMAKE_SOURCE_DIR}/include
+        ${CMAKE_SOURCE_DIR}/third_party
 )
-target_link_libraries(media-server PRIVATE project_options)
+target_link_libraries(media-server PRIVATE project_options Threads::Threads)
 target_compile_definitions(media-server PRIVATE
     RK_PROJECT_VERSION="${PROJECT_VERSION}"
     RK_GIT_SHA="${RK_GIT_SHA}"
@@ -68,5 +74,7 @@ if(BUILD_SAMPLES)
     add_subdirectory(samples)
 endif()
 
+add_subdirectory(plugins)
+
 include(GNUInstallDirs)
 install(FILES configs/sample_cam1.json DESTINATION ${CMAKE_INSTALL_DATADIR}/rk3588-media-server)
diff --git a/configs/sample_cam1.json b/configs/sample_cam1.json
index ac62457..182426f 100644
--- a/configs/sample_cam1.json
+++ b/configs/sample_cam1.json
@@ -1,4 +1,5 @@
 {
+  "queue": { "size": 8, "strategy": "drop_oldest" },
   "graphs": [
     {
       "name": "cam1",
@@ -8,13 +9,20 @@
           "type": "input_rtsp",
           "role": "source",
           "enable": true,
-          "url": "rtsp://user:pass@ip/stream1"
+          "url": "rtsp://user:pass@ip/stream1",
+          "fps": 25,
+          "width": 1920,
+          "height": 1080
         },
         {
           "id": "pub_cam1",
           "type": "publish",
           "role": "sink",
           "enable": true,
+          "codec": "h264",
+          "fps": 25,
+          "gop": 50,
+          "bitrate_kbps": 4000,
           "outputs": [
             { "proto": "rtsp", "port": 8554, "path": "/live/cam1" }
           ]
diff --git a/include/frame/frame.h b/include/frame/frame.h
index 006bc1a..ba9e0be 100644
--- a/include/frame/frame.h
+++ b/include/frame/frame.h
@@ -17,6 +17,8 @@ struct Frame {
     int height = 0;
     PixelFormat format = PixelFormat::UNKNOWN;
 
+    int stride = 0;
+
     int dma_fd = -1;
     uint64_t pts = 0;
     uint64_t frame_id = 0;
diff --git a/include/graph_manager.h b/include/graph_manager.h
new file mode 100644
index 0000000..6fe36ba
--- /dev/null
+++ b/include/graph_manager.h
@@ -0,0 +1,60 @@
+#pragma once
+
+#include <memory>
+#include <string>
+#include <mutex>
+#include <condition_variable>
+#include <vector>
+
+#include "node.h"
+#include "plugin_loader.h"
+#include "utils/simple_json.h"
+
+namespace rk3588 {
+
+class Graph {
+public:
+    explicit Graph(std::string name);
+    ~Graph();
+
+    bool Build(const SimpleJson& graph_cfg, PluginLoader& loader, size_t default_queue_size,
+               QueueDropStrategy default_strategy, std::string& err);
+    bool Start();
+    void Stop();
+
+private:
+    struct NodeEntry {
+        std::string id;
+        std::string type;
+        bool enabled = true;
+        SimpleJson config;
+        NodeContext context;
+        std::unique_ptr<INode> node;
+    };
+
+    std::string name_;
+    std::vector<NodeEntry> nodes_;
+};
+
+class GraphManager {
+public:
+    explicit GraphManager(std::string plugin_dir = "plugins");
+    ~GraphManager();
+
+    static bool LoadConfigFile(const std::string& path, SimpleJson& out, std::string& err);
+
+    bool Build(const SimpleJson& root_cfg, std::string& err);
+    bool StartAll();
+    void StopAll();
+    void RequestStop();
+    void BlockUntilStop();
+
+private:
+    bool running_ = false;
+    PluginLoader loader_;
+    std::vector<std::unique_ptr<Graph>> graphs_;
+    std::mutex mu_;
+    std::condition_variable cv_;
+};
+
+}  // namespace rk3588
diff --git a/include/media_server_app.h b/include/media_server_app.h
new file mode 100644
index 0000000..c8564e0
--- /dev/null
+++ b/include/media_server_app.h
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <string>
+
+#include "graph_manager.h"
+
+namespace rk3588 {
+
+class MediaServerApp {
+public:
+    explicit MediaServerApp(std::string config_path);
+    int Start();
+
+private:
+    std::string config_path_;
+    GraphManager graph_manager_;
+};
+
+}  // namespace rk3588
diff --git a/include/node.h b/include/node.h
new file mode 100644
index 0000000..e481d8e
--- /dev/null
+++ b/include/node.h
@@ -0,0 +1,50 @@
+#pragma once
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "frame/frame.h"
+#include "utils/simple_json.h"
+#include "utils/spsc_queue.h"
+
+namespace rk3588 {
+
+using FramePtr = std::shared_ptr<Frame>;
+
+struct NodeContext {
+    // For nodes with upstream input.
+    std::shared_ptr<SpscQueue<FramePtr>> input_queue;
+    // For nodes that produce downstream outputs (one queue per outgoing edge).
+    std::vector<std::shared_ptr<SpscQueue<FramePtr>>> output_queues;
+};
+
+class INode {
+public:
+    virtual ~INode() = default;
+    virtual std::string Id() const = 0;
+    virtual std::string Type() const = 0;
+    virtual bool Init(const SimpleJson& config, const NodeContext& ctx) = 0;
+    virtual bool Start() = 0;
+    virtual void Stop() = 0;
+};
+
+constexpr int kNodeAbiVersion = 1;
+
+using CreateNodeFn = INode* (*)();
+using DestroyNodeFn = void (*)(INode*);
+using GetTypeFn = const char* (*)();
+using GetAbiFn = int (*)();
+
+#define REGISTER_NODE(NodeClass, NodeTypeStr)                        \
+    extern "C" rk3588::INode* CreateNode() {                        \
+        return new NodeClass();                                      \
+    }                                                                \
+    extern "C" const char* GetNodeType() {                          \
+        return NodeTypeStr;                                          \
+    }                                                                \
+    extern "C" int GetAbiVersion() {                                \
+        return rk3588::kNodeAbiVersion;                              \
+    }
+
+}  // namespace rk3588
diff --git a/include/plugin_loader.h b/include/plugin_loader.h
new file mode 100644
index 0000000..2e6a331
--- /dev/null
+++ b/include/plugin_loader.h
@@ -0,0 +1,33 @@
+#pragma once
+
+#include <map>
+#include <memory>
+#include <string>
+
+#include "node.h"
+
+namespace rk3588 {
+
+class PluginLoader {
+public:
+    explicit PluginLoader(std::string plugin_dir);
+    ~PluginLoader();
+
+    std::unique_ptr<INode> Create(const std::string& type, std::string& err);
+
+private:
+    struct PluginHandle {
+        void* handle = nullptr;
+        CreateNodeFn create = nullptr;
+        GetTypeFn get_type = nullptr;
+        GetAbiFn get_abi = nullptr;
+    };
+
+    std::string BuildLibraryPath(const std::string& type) const;
+    bool LoadPlugin(const std::string& type, PluginHandle& out, std::string& err);
+
+    std::string plugin_dir_;
+    std::map<std::string, PluginHandle> cache_;
+};
+
+}  // namespace rk3588
diff --git a/include/utils/simple_json.h b/include/utils/simple_json.h
new file mode 100644
index 0000000..71634a7
--- /dev/null
+++ b/include/utils/simple_json.h
@@ -0,0 +1,304 @@
+// Minimal JSON DOM and parser for configuration use.
+// Supports objects, arrays, strings, numbers, booleans, and null.
+// Not a full JSON implementation but sufficient for structured config files.
+
+#pragma once
+
+#include <cctype>
+#include <map>
+#include <optional>
+#include <string>
+#include <string_view>
+#include <variant>
+#include <vector>
+
+namespace rk3588 {
+
+class SimpleJson {
+public:
+    enum class Type { Null, Bool, Number, String, Array, Object };
+    using Array = std::vector<SimpleJson>;
+    using Object = std::map<std::string, SimpleJson>;
+    using Variant = std::variant<std::nullptr_t, bool, double, std::string, Array, Object>;
+
+    SimpleJson() : value_(nullptr) {}
+    explicit SimpleJson(std::nullptr_t) : value_(nullptr) {}
+    explicit SimpleJson(bool b) : value_(b) {}
+    explicit SimpleJson(double n) : value_(n) {}
+    explicit SimpleJson(std::string s) : value_(std::move(s)) {}
+    explicit SimpleJson(Array a) : value_(std::move(a)) {}
+    explicit SimpleJson(Object o) : value_(std::move(o)) {}
+
+    Type type() const {
+        return static_cast<Type>(value_.index());
+    }
+
+    bool IsNull() const { return type() == Type::Null; }
+    bool IsBool() const { return type() == Type::Bool; }
+    bool IsNumber() const { return type() == Type::Number; }
+    bool IsString() const { return type() == Type::String; }
+    bool IsArray() const { return type() == Type::Array; }
+    bool IsObject() const { return type() == Type::Object; }
+
+    bool AsBool(bool def = false) const {
+        return std::holds_alternative<bool>(value_) ? std::get<bool>(value_) : def;
+    }
+
+    double AsNumber(double def = 0.0) const {
+        return std::holds_alternative<double>(value_) ? std::get<double>(value_) : def;
+    }
+
+    int AsInt(int def = 0) const {
+        return static_cast<int>(AsNumber(static_cast<double>(def)));
+    }
+
+    const std::string& AsString(const std::string& def = EmptyString()) const {
+        if (const auto* s = std::get_if<std::string>(&value_)) {
+            return *s;
+        }
+        return def;
+    }
+
+    const Array& AsArray() const {
+        static const Array kEmpty;
+        if (const auto* a = std::get_if<Array>(&value_)) {
+            return *a;
+        }
+        return kEmpty;
+    }
+
+    const Object& AsObject() const {
+        static const Object kEmpty;
+        if (const auto* o = std::get_if<Object>(&value_)) {
+            return *o;
+        }
+        return kEmpty;
+    }
+
+    const SimpleJson* Find(const std::string& key) const {
+        if (const auto* o = std::get_if<Object>(&value_)) {
+            auto it = o->find(key);
+            if (it != o->end()) {
+                return &it->second;
+            }
+        }
+        return nullptr;
+    }
+
+    template <typename T>
+    T ValueOr(const std::string& key, const T& def) const {
+        const SimpleJson* child = Find(key);
+        if (!child) return def;
+        if constexpr (std::is_same_v<T, std::string>) {
+            return child->AsString(def);
+        } else if constexpr (std::is_same_v<T, double>) {
+            return child->AsNumber(def);
+        } else if constexpr (std::is_same_v<T, int>) {
+            return child->AsInt(def);
+        } else if constexpr (std::is_same_v<T, bool>) {
+            return child->AsBool(def);
+        } else {
+            return def;
+        }
+    }
+
+private:
+    Variant value_;
+
+    static const std::string& EmptyString() {
+        static const std::string empty;
+        return empty;
+    }
+};
+
+inline void SkipWhitespace(std::string_view text, size_t& pos) {
+    while (pos < text.size() && std::isspace(static_cast<unsigned char>(text[pos]))) {
+        ++pos;
+    }
+}
+
+inline bool ConsumeLiteral(std::string_view text, size_t& pos, std::string_view lit) {
+    if (text.substr(pos, lit.size()) == lit) {
+        pos += lit.size();
+        return true;
+    }
+    return false;
+}
+
+inline bool ParseString(std::string_view text, size_t& pos, std::string& out, std::string& err) {
+    if (text[pos] != '"') return false;
+    ++pos;  // skip opening quote
+    while (pos < text.size()) {
+        char c = text[pos++];
+        if (c == '"') {
+            return true;
+        }
+        if (c == '\\') {
+            if (pos >= text.size()) {
+                err = "Unexpected end of input in string escape";
+                return false;
+            }
+            char esc = text[pos++];
+            switch (esc) {
+                case '"': out.push_back('"'); break;
+                case '\\': out.push_back('\\'); break;
+                case '/': out.push_back('/'); break;
+                case 'b': out.push_back('\b'); break;
+                case 'f': out.push_back('\f'); break;
+                case 'n': out.push_back('\n'); break;
+                case 'r': out.push_back('\r'); break;
+                case 't': out.push_back('\t'); break;
+                default:
+                    err = "Unsupported escape sequence";
+                    return false;
+            }
+        } else {
+            out.push_back(c);
+        }
+    }
+    err = "Unterminated string";
+    return false;
+}
+
+inline bool ParseNumber(std::string_view text, size_t& pos, double& out) {
+    size_t start = pos;
+    if (text[pos] == '-') ++pos;
+    while (pos < text.size() && std::isdigit(static_cast<unsigned char>(text[pos]))) ++pos;
+    if (pos < text.size() && text[pos] == '.') {
+        ++pos;
+        while (pos < text.size() && std::isdigit(static_cast<unsigned char>(text[pos]))) ++pos;
+    }
+    if (pos < text.size() && (text[pos] == 'e' || text[pos] == 'E')) {
+        ++pos;
+        if (pos < text.size() && (text[pos] == '+' || text[pos] == '-')) ++pos;
+        while (pos < text.size() && std::isdigit(static_cast<unsigned char>(text[pos]))) ++pos;
+    }
+    try {
+        out = std::stod(std::string{text.substr(start, pos - start)});
+        return true;
+    } catch (...) {
+        return false;
+    }
+}
+
+inline bool ParseValue(std::string_view text, size_t& pos, SimpleJson& out, std::string& err);
+
+inline bool ParseArray(std::string_view text, size_t& pos, SimpleJson& out, std::string& err) {
+    if (text[pos] != '[') return false;
+    ++pos;
+    SkipWhitespace(text, pos);
+    SimpleJson::Array arr;
+    if (pos < text.size() && text[pos] == ']') {
+        ++pos;
+        out = SimpleJson(std::move(arr));
+        return true;
+    }
+    while (pos < text.size()) {
+        SimpleJson element;
+        if (!ParseValue(text, pos, element, err)) return false;
+        arr.push_back(std::move(element));
+        SkipWhitespace(text, pos);
+        if (pos < text.size() && text[pos] == ',') {
+            ++pos;
+            SkipWhitespace(text, pos);
+            continue;
+        }
+        if (pos < text.size() && text[pos] == ']') {
+            ++pos;
+            out = SimpleJson(std::move(arr));
+            return true;
+        }
+        err = "Expected ',' or ']' in array";
+        return false;
+    }
+    err = "Unterminated array";
+    return false;
+}
+
+inline bool ParseObject(std::string_view text, size_t& pos, SimpleJson& out, std::string& err) {
+    if (text[pos] != '{') return false;
+    ++pos;
+    SkipWhitespace(text, pos);
+    SimpleJson::Object obj;
+    if (pos < text.size() && text[pos] == '}') {
+        ++pos;
+        out = SimpleJson(std::move(obj));
+        return true;
+    }
+    while (pos < text.size()) {
+        SkipWhitespace(text, pos);
+        if (pos >= text.size() || text[pos] != '"') {
+            err = "Expected string key";
+            return false;
+        }
+        std::string key;
+        if (!ParseString(text, pos, key, err)) return false;
+        SkipWhitespace(text, pos);
+        if (pos >= text.size() || text[pos] != ':') {
+            err = "Expected ':' after object key";
+            return false;
+        }
+        ++pos;
+        SkipWhitespace(text, pos);
+        SimpleJson value;
+        if (!ParseValue(text, pos, value, err)) return false;
+        obj.emplace(std::move(key), std::move(value));
+        SkipWhitespace(text, pos);
+        if (pos < text.size() && text[pos] == ',') {
+            ++pos;
+            SkipWhitespace(text, pos);
+            continue;
+        }
+        if (pos < text.size() && text[pos] == '}') {
+            ++pos;
+            out = SimpleJson(std::move(obj));
+            return true;
+        }
+        err = "Expected ',' or '}' in object";
+        return false;
+    }
+    err = "Unterminated object";
+    return false;
+}
+
+inline bool ParseValue(std::string_view text, size_t& pos, SimpleJson& out, std::string& err) {
+    SkipWhitespace(text, pos);
+    if (pos >= text.size()) {
+        err = "Unexpected end of input";
+        return false;
+    }
+    char c = text[pos];
+    if (c == 'n') {
+        if (ConsumeLiteral(text, pos, "null")) { out = SimpleJson(nullptr); return true; }
+    } else if (c == 't') {
+        if (ConsumeLiteral(text, pos, "true")) { out = SimpleJson(true); return true; }
+    } else if (c == 'f') {
+        if (ConsumeLiteral(text, pos, "false")) { out = SimpleJson(false); return true; }
+    } else if (c == '"') {
+        std::string s;
+        if (ParseString(text, pos, s, err)) { out = SimpleJson(std::move(s)); return true; }
+        return false;
+    } else if (c == '[') {
+        return ParseArray(text, pos, out, err);
+    } else if (c == '{') {
+        return ParseObject(text, pos, out, err);
+    } else if (c == '-' || std::isdigit(static_cast<unsigned char>(c))) {
+        double num = 0.0;
+        if (ParseNumber(text, pos, num)) { out = SimpleJson(num); return true; }
+    }
+    err = "Invalid JSON value";
+    return false;
+}
+
+inline bool ParseSimpleJson(const std::string& input, SimpleJson& out, std::string& err) {
+    size_t pos = 0;
+    if (!ParseValue(input, pos, out, err)) return false;
+    SkipWhitespace(input, pos);
+    if (pos != input.size()) {
+        err = "Unexpected characters after JSON document";
+        return false;
+    }
+    return true;
+}
+
+}  // namespace rk3588
diff --git a/include/utils/spsc_queue.h b/include/utils/spsc_queue.h
new file mode 100644
index 0000000..630bffa
--- /dev/null
+++ b/include/utils/spsc_queue.h
@@ -0,0 +1,78 @@
+#pragma once
+
+#include <chrono>
+#include <condition_variable>
+#include <cstddef>
+#include <deque>
+#include <mutex>
+
+namespace rk3588 {
+
+enum class QueueDropStrategy {
+    DropOldest,
+    Block
+};
+
+template <typename T>
+class SpscQueue {
+public:
+    SpscQueue(size_t capacity, QueueDropStrategy strategy)
+        : capacity_(capacity), strategy_(strategy) {}
+
+    bool Push(T item) {
+        std::unique_lock<std::mutex> lock(mu_);
+        if (queue_.size() >= capacity_) {
+            if (strategy_ == QueueDropStrategy::DropOldest) {
+                queue_.pop_front();
+                ++dropped_;
+            } else {
+                // Block until space is available
+                space_cv_.wait(lock, [&] { return queue_.size() < capacity_ || stop_; });
+                if (stop_) return false;
+            }
+        }
+        queue_.push_back(std::move(item));
+        data_cv_.notify_one();
+        return true;
+    }
+
+    bool Pop(T& out, std::chrono::milliseconds timeout) {
+        std::unique_lock<std::mutex> lock(mu_);
+        if (!data_cv_.wait_for(lock, timeout, [&] { return !queue_.empty() || stop_; })) {
+            return false;
+        }
+        if (queue_.empty()) return false;
+        out = std::move(queue_.front());
+        queue_.pop_front();
+        space_cv_.notify_one();
+        return true;
+    }
+
+    void Stop() {
+        std::lock_guard<std::mutex> lock(mu_);
+        stop_ = true;
+        data_cv_.notify_all();
+        space_cv_.notify_all();
+    }
+
+    size_t Size() const {
+        std::lock_guard<std::mutex> lock(mu_);
+        return queue_.size();
+    }
+
+    size_t Capacity() const { return capacity_; }
+
+    size_t DroppedCount() const { return dropped_; }
+
+private:
+    size_t capacity_ = 0;
+    QueueDropStrategy strategy_ = QueueDropStrategy::DropOldest;
+    mutable std::mutex mu_;
+    std::condition_variable data_cv_;
+    std::condition_variable space_cv_;
+    std::deque<T> queue_;
+    bool stop_ = false;
+    size_t dropped_ = 0;
+};
+
+}  // namespace rk3588
diff --git a/plugins/CMakeLists.txt b/plugins/CMakeLists.txt
new file mode 100644
index 0000000..40e3d35
--- /dev/null
+++ b/plugins/CMakeLists.txt
@@ -0,0 +1,24 @@
+set(RK_PLUGIN_OUTPUT_DIR ${CMAKE_BINARY_DIR}/plugins)
+
+add_library(input_rtsp SHARED input_rtsp/input_rtsp_node.cpp)
+target_include_directories(input_rtsp PRIVATE ${CMAKE_SOURCE_DIR}/include ${CMAKE_SOURCE_DIR}/third_party)
+target_link_libraries(input_rtsp PRIVATE project_options Threads::Threads)
+set_target_properties(input_rtsp PROPERTIES
+    OUTPUT_NAME "input_rtsp"
+    LIBRARY_OUTPUT_DIRECTORY ${RK_PLUGIN_OUTPUT_DIR}
+    RUNTIME_OUTPUT_DIRECTORY ${RK_PLUGIN_OUTPUT_DIR}
+)
+
+add_library(publish SHARED publish/publish_node.cpp)
+target_include_directories(publish PRIVATE ${CMAKE_SOURCE_DIR}/include ${CMAKE_SOURCE_DIR}/third_party)
+target_link_libraries(publish PRIVATE project_options Threads::Threads)
+set_target_properties(publish PROPERTIES
+    OUTPUT_NAME "publish"
+    LIBRARY_OUTPUT_DIRECTORY ${RK_PLUGIN_OUTPUT_DIR}
+    RUNTIME_OUTPUT_DIRECTORY ${RK_PLUGIN_OUTPUT_DIR}
+)
+
+install(TARGETS input_rtsp publish
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}/rk3588-media-server/plugins
+    RUNTIME DESTINATION ${CMAKE_INSTALL_LIBDIR}/rk3588-media-server/plugins
+)
diff --git a/plugins/input_rtsp/input_rtsp_node.cpp b/plugins/input_rtsp/input_rtsp_node.cpp
new file mode 100644
index 0000000..b5516ae
--- /dev/null
+++ b/plugins/input_rtsp/input_rtsp_node.cpp
@@ -0,0 +1,77 @@
+#include <atomic>
+#include <chrono>
+#include <iostream>
+#include <thread>
+
+#include "node.h"
+
+namespace rk3588 {
+
+class InputRtspNode : public INode {
+public:
+    std::string Id() const override { return id_; }
+    std::string Type() const override { return "input_rtsp"; }
+
+    bool Init(const SimpleJson& config, const NodeContext& ctx) override {
+        id_ = config.ValueOr<std::string>("id", "input_rtsp");
+        url_ = config.ValueOr<std::string>("url", "");
+        fps_ = config.ValueOr<int>("fps", 25);
+        width_ = config.ValueOr<int>("width", 1920);
+        height_ = config.ValueOr<int>("height", 1080);
+        if (ctx.output_queues.empty()) {
+            std::cerr << "[input_rtsp] no downstream queue configured for node " << id_ << "\n";
+            return false;
+        }
+        out_queue_ = ctx.output_queues[0];
+        return true;
+    }
+
+    bool Start() override {
+        if (!out_queue_) return false;
+        running_.store(true);
+        worker_ = std::thread(&InputRtspNode::Loop, this);
+        std::cout << "[input_rtsp] start url=" << url_ << " fps=" << fps_ << "\n";
+        return true;
+    }
+
+    void Stop() override {
+        running_.store(false);
+        if (out_queue_) out_queue_->Stop();
+        if (worker_.joinable()) worker_.join();
+    }
+
+private:
+    void Loop() {
+        using namespace std::chrono;
+        auto frame_interval = fps_ > 0 ? milliseconds(1000 / fps_) : milliseconds(40);
+        while (running_.load()) {
+            auto frame = std::make_shared<Frame>();
+            frame->width = width_;
+            frame->height = height_;
+            frame->format = PixelFormat::NV12;
+            frame->frame_id = ++frame_id_;
+            frame->pts = duration_cast<milliseconds>(steady_clock::now().time_since_epoch()).count();
+            out_queue_->Push(frame);
+
+            if (frame_id_ % 100 == 0) {
+                std::cout << "[input_rtsp] generated frame " << frame_id_ << " queue="
+                          << out_queue_->Size() << " drops=" << out_queue_->DroppedCount() << "\n";
+            }
+            std::this_thread::sleep_for(frame_interval);
+        }
+    }
+
+    std::string id_;
+    std::string url_;
+    int fps_ = 25;
+    int width_ = 1920;
+    int height_ = 1080;
+    std::atomic<bool> running_{false};
+    std::shared_ptr<SpscQueue<FramePtr>> out_queue_;
+    std::thread worker_;
+    uint64_t frame_id_ = 0;
+};
+
+REGISTER_NODE(InputRtspNode, "input_rtsp");
+
+}  // namespace rk3588
diff --git a/plugins/publish/publish_node.cpp b/plugins/publish/publish_node.cpp
new file mode 100644
index 0000000..cbd6c80
--- /dev/null
+++ b/plugins/publish/publish_node.cpp
@@ -0,0 +1,86 @@
+#include <atomic>
+#include <chrono>
+#include <iostream>
+#include <thread>
+
+#include "node.h"
+
+namespace rk3588 {
+
+class PublishNode : public INode {
+public:
+    std::string Id() const override { return id_; }
+    std::string Type() const override { return "publish"; }
+
+    bool Init(const SimpleJson& config, const NodeContext& ctx) override {
+        id_ = config.ValueOr<std::string>("id", "publish");
+        input_queue_ = ctx.input_queue;
+        codec_ = config.ValueOr<std::string>("codec", "h264");
+        fps_ = config.ValueOr<int>("fps", 25);
+        gop_ = config.ValueOr<int>("gop", 50);
+        bitrate_kbps_ = config.ValueOr<int>("bitrate_kbps", 4000);
+        // Outputs array optional; log first entry if present.
+        const SimpleJson* outputs = config.Find("outputs");
+        if (outputs && outputs->IsArray() && !outputs->AsArray().empty()) {
+            const auto& first = outputs->AsArray().front();
+            if (first.IsObject()) {
+                port_ = first.ValueOr<int>("port", 8554);
+                path_ = first.ValueOr<std::string>("path", "/live/cam1");
+            }
+        }
+        if (!input_queue_) {
+            std::cerr << "[publish] no input queue for node " << id_ << "\n";
+            return false;
+        }
+        return true;
+    }
+
+    bool Start() override {
+        if (!input_queue_) return false;
+        running_.store(true);
+        worker_ = std::thread(&PublishNode::Loop, this);
+        std::cout << "[publish] start codec=" << codec_ << " fps=" << fps_ << " gop=" << gop_
+                  << " bitrate=" << bitrate_kbps_ << "kbps target rtsp://0.0.0.0:" << port_
+                  << path_ << "\n";
+        return true;
+    }
+
+    void Stop() override {
+        running_.store(false);
+        if (input_queue_) input_queue_->Stop();
+        if (worker_.joinable()) worker_.join();
+    }
+
+private:
+    void Loop() {
+        using namespace std::chrono;
+        FramePtr frame;
+        while (running_.load()) {
+            if (!input_queue_->Pop(frame, milliseconds(200))) {
+                continue;
+            }
+            ++encoded_frames_;
+            if (encoded_frames_ % 100 == 0 && frame) {
+                std::cout << "[publish] encoded frame " << frame->frame_id
+                          << " queue=" << input_queue_->Size()
+                          << " drops=" << input_queue_->DroppedCount() << "\n";
+            }
+        }
+    }
+
+    std::string id_;
+    std::string codec_ = "h264";
+    int fps_ = 25;
+    int gop_ = 50;
+    int bitrate_kbps_ = 4000;
+    int port_ = 8554;
+    std::string path_ = "/live/cam1";
+    std::atomic<bool> running_{false};
+    std::shared_ptr<SpscQueue<FramePtr>> input_queue_;
+    std::thread worker_;
+    uint64_t encoded_frames_ = 0;
+};
+
+REGISTER_NODE(PublishNode, "publish");
+
+}  // namespace rk3588
diff --git a/src/graph_manager.cpp b/src/graph_manager.cpp
new file mode 100644
index 0000000..4cff3ea
--- /dev/null
+++ b/src/graph_manager.cpp
@@ -0,0 +1,215 @@
+#include "graph_manager.h"
+
+#include <fstream>
+#include <iostream>
+#include <map>
+#include <set>
+
+namespace rk3588 {
+
+Graph::Graph(std::string name) : name_(std::move(name)) {}
+
+Graph::~Graph() { Stop(); }
+
+bool Graph::Build(const SimpleJson& graph_cfg, PluginLoader& loader, size_t default_queue_size,
+                  QueueDropStrategy default_strategy, std::string& err) {
+    const auto& obj = graph_cfg.AsObject();
+    auto name_it = obj.find("name");
+    if (name_it != obj.end() && name_it->second.IsString()) {
+        name_ = name_it->second.AsString(name_);
+    }
+
+    // Parse nodes
+    auto nodes_it = obj.find("nodes");
+    if (nodes_it == obj.end() || !nodes_it->second.IsArray()) {
+        err = "Graph missing 'nodes' array";
+        return false;
+    }
+
+    for (const auto& node_val : nodes_it->second.AsArray()) {
+        if (!node_val.IsObject()) {
+            err = "Node entry is not object";
+            return false;
+        }
+        NodeEntry entry;
+        entry.config = node_val;
+        entry.id = node_val.ValueOr<std::string>("id", "");
+        entry.type = node_val.ValueOr<std::string>("type", "");
+        entry.enabled = node_val.ValueOr<bool>("enable", true);
+        if (entry.id.empty() || entry.type.empty()) {
+            err = "Node missing id or type";
+            return false;
+        }
+        nodes_.push_back(std::move(entry));
+    }
+
+    // Parse edges
+    auto edges_it = obj.find("edges");
+    if (edges_it == obj.end() || !edges_it->second.IsArray()) {
+        err = "Graph missing 'edges' array";
+        return false;
+    }
+
+    std::map<std::string, NodeEntry*> id_to_node;
+    for (auto& n : nodes_) {
+        id_to_node[n.id] = &n;
+    }
+
+    for (const auto& edge_val : edges_it->second.AsArray()) {
+        if (!edge_val.IsArray() || edge_val.AsArray().size() != 2) {
+            err = "Edge must be [from, to]";
+            return false;
+        }
+        const auto& edge_arr = edge_val.AsArray();
+        std::string from = edge_arr[0].AsString("");
+        std::string to = edge_arr[1].AsString("");
+        if (from.empty() || to.empty()) {
+            err = "Edge has empty endpoint";
+            return false;
+        }
+        auto from_it = id_to_node.find(from);
+        auto to_it = id_to_node.find(to);
+        if (from_it == id_to_node.end() || to_it == id_to_node.end()) {
+            err = "Edge references unknown node";
+            return false;
+        }
+        size_t qsize = default_queue_size;
+        QueueDropStrategy strategy = default_strategy;
+        if (const auto* qcfg = edge_val.Find("queue")) {
+            if (qcfg->IsObject()) {
+                qsize = static_cast<size_t>(qcfg->ValueOr<int>("size", static_cast<int>(default_queue_size)));
+                std::string strat = qcfg->ValueOr<std::string>("strategy", "drop_oldest");
+                if (strat == "drop_oldest") strategy = QueueDropStrategy::DropOldest;
+                else strategy = QueueDropStrategy::Block;
+            }
+        }
+        auto queue = std::make_shared<SpscQueue<FramePtr>>(qsize, strategy);
+        from_it->second->context.output_queues.push_back(queue);
+        // For now support single input per node; first edge wins.
+        if (!to_it->second->context.input_queue) {
+            to_it->second->context.input_queue = queue;
+        }
+    }
+
+    // Instantiate nodes via plugins
+    for (auto& entry : nodes_) {
+        if (!entry.enabled) continue;
+        std::string load_err;
+        entry.node = loader.Create(entry.type, load_err);
+        if (!entry.node) {
+            err = load_err;
+            return false;
+        }
+        if (!entry.node->Init(entry.config, entry.context)) {
+            err = "Init failed for node " + entry.id;
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool Graph::Start() {
+    for (auto& entry : nodes_) {
+        if (!entry.enabled || !entry.node) continue;
+        if (!entry.node->Start()) {
+            std::cerr << "[Graph] failed to start node: " << entry.id << "\n";
+            return false;
+        }
+    }
+    std::cout << "[Graph] started graph " << name_ << " with " << nodes_.size() << " nodes\n";
+    return true;
+}
+
+void Graph::Stop() {
+    for (auto it = nodes_.rbegin(); it != nodes_.rend(); ++it) {
+        if (it->node) {
+            it->node->Stop();
+        }
+        if (it->context.input_queue) it->context.input_queue->Stop();
+        for (auto& q : it->context.output_queues) q->Stop();
+    }
+}
+
+GraphManager::GraphManager(std::string plugin_dir)
+    : loader_(std::move(plugin_dir)) {}
+
+GraphManager::~GraphManager() { StopAll(); }
+
+bool GraphManager::LoadConfigFile(const std::string& path, SimpleJson& out, std::string& err) {
+    std::ifstream ifs(path);
+    if (!ifs.is_open()) {
+        err = "Failed to open config: " + path;
+        return false;
+    }
+    std::string content((std::istreambuf_iterator<char>(ifs)), std::istreambuf_iterator<char>());
+    return ParseSimpleJson(content, out, err);
+}
+
+bool GraphManager::Build(const SimpleJson& root_cfg, std::string& err) {
+    auto graphs_it = root_cfg.AsObject().find("graphs");
+    if (graphs_it == root_cfg.AsObject().end() || !graphs_it->second.IsArray()) {
+        err = "Root config missing 'graphs' array";
+        return false;
+    }
+
+    size_t default_queue_size = 8;
+    QueueDropStrategy default_strategy = QueueDropStrategy::DropOldest;
+    if (const auto* queue_cfg = root_cfg.Find("queue")) {
+        if (queue_cfg->IsObject()) {
+            default_queue_size = static_cast<size_t>(queue_cfg->ValueOr<int>("size", 8));
+            std::string strategy = queue_cfg->ValueOr<std::string>("strategy", "drop_oldest");
+            if (strategy == "block") default_strategy = QueueDropStrategy::Block;
+        }
+    }
+
+    for (const auto& graph_val : graphs_it->second.AsArray()) {
+        if (!graph_val.IsObject()) {
+            err = "Graph entry is not object";
+            return false;
+        }
+        std::string name = graph_val.ValueOr<std::string>("name", "noname");
+        auto graph = std::make_unique<Graph>(name);
+        if (!graph->Build(graph_val, loader_, default_queue_size, default_strategy, err)) {
+            return false;
+        }
+        graphs_.push_back(std::move(graph));
+    }
+    return true;
+}
+
+bool GraphManager::StartAll() {
+    for (auto& g : graphs_) {
+        if (!g->Start()) {
+            return false;
+        }
+    }
+    {
+        std::lock_guard<std::mutex> lock(mu_);
+        running_ = true;
+    }
+    return true;
+}
+
+void GraphManager::StopAll() {
+    {
+        std::lock_guard<std::mutex> lock(mu_);
+        if (!running_) return;
+        running_ = false;
+    }
+    for (auto& g : graphs_) {
+        g->Stop();
+    }
+    cv_.notify_all();
+}
+
+void GraphManager::RequestStop() {
+    StopAll();
+}
+
+void GraphManager::BlockUntilStop() {
+    std::unique_lock<std::mutex> lock(mu_);
+    cv_.wait(lock, [&] { return !running_; });
+}
+
+}  // namespace rk3588
diff --git a/src/media_server_app.cpp b/src/media_server_app.cpp
index 5225eca..897c5aa 100644
--- a/src/media_server_app.cpp
+++ b/src/media_server_app.cpp
@@ -1,15 +1,52 @@
 #include "media_server_app.h"
 
 #include <iostream>
+#include <signal.h>
+#include <string>
 
 namespace rk3588 {
 
+namespace {
+
+GraphManager* g_manager = nullptr;
+
+void HandleSignal(int) {
+    if (g_manager) {
+        std::cerr << "\n[MediaServerApp] Caught signal, stopping...\n";
+        g_manager->RequestStop();
+    }
+}
+
+}  // namespace
+
 MediaServerApp::MediaServerApp(std::string config_path)
     : config_path_(std::move(config_path)) {}
 
 int MediaServerApp::Start() {
-    std::cout << "[MediaServerApp] config=" << config_path_
-              << " (pipeline execution not yet implemented)\n";
+    SimpleJson root_cfg;
+    std::string err;
+    if (!GraphManager::LoadConfigFile(config_path_, root_cfg, err)) {
+        std::cerr << "[MediaServerApp] Failed to load config: " << err << "\n";
+        return 1;
+    }
+
+    if (!graph_manager_.Build(root_cfg, err)) {
+        std::cerr << "[MediaServerApp] Failed to build graphs: " << err << "\n";
+        return 1;
+    }
+
+    g_manager = &graph_manager_;
+    signal(SIGINT, HandleSignal);
+    signal(SIGTERM, HandleSignal);
+
+    if (!graph_manager_.StartAll()) {
+        std::cerr << "[MediaServerApp] Failed to start graphs\n";
+        return 1;
+    }
+
+    std::cout << "[MediaServerApp] Running. Press Ctrl+C to stop.\n";
+    graph_manager_.BlockUntilStop();
+    std::cout << "[MediaServerApp] Shutdown complete.\n";
     return 0;
 }
 
diff --git a/src/plugin_loader.cpp b/src/plugin_loader.cpp
new file mode 100644
index 0000000..ae82803
--- /dev/null
+++ b/src/plugin_loader.cpp
@@ -0,0 +1,128 @@
+#include "plugin_loader.h"
+
+#include <iostream>
+#include <sstream>
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <dlfcn.h>
+#endif
+
+namespace rk3588 {
+
+namespace {
+
+void* LoadLibraryHandle(const std::string& path, std::string& err) {
+#ifdef _WIN32
+    HMODULE handle = LoadLibraryA(path.c_str());
+    if (!handle) {
+        err = "LoadLibrary failed for " + path;
+    }
+    return handle;
+#else
+    void* handle = dlopen(path.c_str(), RTLD_LAZY);
+    if (!handle) {
+        const char* dl_err = dlerror();
+        err = dl_err ? dl_err : "dlopen failed";
+    }
+    return handle;
+#endif
+}
+
+void CloseLibraryHandle(void* handle) {
+    if (!handle) return;
+#ifdef _WIN32
+    FreeLibrary(static_cast<HMODULE>(handle));
+#else
+    dlclose(handle);
+#endif
+}
+
+void* LoadSymbol(void* handle, const char* name) {
+#ifdef _WIN32
+    return reinterpret_cast<void*>(GetProcAddress(static_cast<HMODULE>(handle), name));
+#else
+    return dlsym(handle, name);
+#endif
+}
+
+std::string SharedLibExtension() {
+#ifdef _WIN32
+    return ".dll";
+#elif __APPLE__
+    return ".dylib";
+#else
+    return ".so";
+#endif
+}
+
+}  // namespace
+
+PluginLoader::PluginLoader(std::string plugin_dir)
+    : plugin_dir_(std::move(plugin_dir)) {}
+
+PluginLoader::~PluginLoader() {
+    for (auto& kv : cache_) {
+        CloseLibraryHandle(kv.second.handle);
+    }
+}
+
+std::string PluginLoader::BuildLibraryPath(const std::string& type) const {
+#ifdef _WIN32
+    return plugin_dir_ + "/" + type + SharedLibExtension();
+#else
+    return plugin_dir_ + "/lib" + type + SharedLibExtension();
+#endif
+}
+
+bool PluginLoader::LoadPlugin(const std::string& type, PluginHandle& out, std::string& err) {
+    std::string path = BuildLibraryPath(type);
+    void* handle = LoadLibraryHandle(path, err);
+    if (!handle) return false;
+
+    auto create = reinterpret_cast<CreateNodeFn>(LoadSymbol(handle, "CreateNode"));
+    auto get_type = reinterpret_cast<GetTypeFn>(LoadSymbol(handle, "GetNodeType"));
+    auto get_abi = reinterpret_cast<GetAbiFn>(LoadSymbol(handle, "GetAbiVersion"));
+    if (!create || !get_type || !get_abi) {
+        err = "Missing required symbols in plugin: " + path;
+        CloseLibraryHandle(handle);
+        return false;
+    }
+    if (get_abi() != kNodeAbiVersion) {
+        std::ostringstream oss;
+        oss << "ABI mismatch for plugin " << type << ": expected " << kNodeAbiVersion
+            << " got " << get_abi();
+        err = oss.str();
+        CloseLibraryHandle(handle);
+        return false;
+    }
+    out.handle = handle;
+    out.create = create;
+    out.get_type = get_type;
+    out.get_abi = get_abi;
+    return true;
+}
+
+std::unique_ptr<INode> PluginLoader::Create(const std::string& type, std::string& err) {
+    auto it = cache_.find(type);
+    if (it == cache_.end()) {
+        PluginHandle handle;
+        if (!LoadPlugin(type, handle, err)) {
+            std::cerr << "[PluginLoader] Failed to load plugin '" << type << "': " << err
+                      << "\n";
+            return nullptr;
+        }
+        it = cache_.emplace(type, std::move(handle)).first;
+    }
+
+    PluginHandle& handle = it->second;
+    std::unique_ptr<INode> node(handle.create());
+    if (!node) {
+        err = "CreateNode returned null for type " + type;
+        return nullptr;
+    }
+    return node;
+}
+
+}  // namespace rk3588