diff --git a/bin/main.cpp b/bin/main.cpp
index 4bf6b48..3054b54 100644
--- a/bin/main.cpp
+++ b/bin/main.cpp
@@ -13,12 +13,6 @@ using namespace toucan;
 
 int main(int argc, char** argv)
 {
-    std::filesystem::path parentPath = std::filesystem::path(argv[0]).parent_path();
-    auto host = std::make_shared<Host>(std::vector<std::filesystem::path>{
-        parentPath,
-        parentPath / ".." / ".."});
-    return 0;
-
     // Command line arguments.
     if (argc < 3)
     {
@@ -33,6 +27,7 @@ int main(int argc, char** argv)
         std::cout << std::endl;
         return 1;
     }
+    const std::filesystem::path parentPath = std::filesystem::path(argv[0]).parent_path();
     const std::filesystem::path inputPath(argv[1]);
     const std::filesystem::path outputPath(argv[2]);
     const auto outputSplit = splitFileNameNumber(outputPath.stem().string());
@@ -69,6 +64,11 @@ int main(int argc, char** argv)
     const auto traverse = std::make_shared<TimelineTraverse>(inputPath.parent_path(), timeline);
     const IMATH_NAMESPACE::V2d& imageSize = traverse->getImageSize();
 
+    // Create the host.
+    auto host = std::make_shared<Host>(std::vector<std::filesystem::path>{
+        parentPath,
+        parentPath / ".." / ".."});
+
     // Initialize the filmstrip.
     OIIO::ImageBuf filmstripBuf;
     const int thumbnailWidth = 120;
@@ -97,7 +97,7 @@ int main(int argc, char** argv)
         if (auto op = traverse->exec(time))
         {
             // Execute the image operation graph.
-            const auto buf = op->exec(time);
+            const auto buf = op->exec(time, host);
 
             // Save the image.
             if (!filmstrip)
diff --git a/lib/toucan/BoxOp.cpp b/lib/toucan/BoxOp.cpp
index ddca04a..6da107c 100644
--- a/lib/toucan/BoxOp.cpp
+++ b/lib/toucan/BoxOp.cpp
@@ -30,7 +30,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf BoxOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf BoxOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -40,7 +42,7 @@ namespace toucan
             {
                 offsetTime -= _timeOffset;
             }
-            buf = _inputs[0]->exec(offsetTime);
+            buf = _inputs[0]->exec(offsetTime, host);
             OIIO::ImageBufAlgo::render_box(
                 buf,
                 _data.pos1.x,
diff --git a/lib/toucan/BoxOp.h b/lib/toucan/BoxOp.h
index 637e16b..1806042 100644
--- a/lib/toucan/BoxOp.h
+++ b/lib/toucan/BoxOp.h
@@ -30,7 +30,9 @@ namespace toucan
         const BoxData& getData() const;
         void setData(const BoxData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         BoxData _data;
diff --git a/lib/toucan/CMakeLists.txt b/lib/toucan/CMakeLists.txt
index 4ce1442..1e885e9 100644
--- a/lib/toucan/CMakeLists.txt
+++ b/lib/toucan/CMakeLists.txt
@@ -54,7 +54,9 @@ set(SOURCE
     TransitionOp.cpp
     Util.cpp)
 if(WIN32)
-    list(APPEND SOURCE UtilWin32.cpp)
+    list(APPEND SOURCE
+        PluginWin32.cpp
+        UtilWin32.cpp)
 endif()
 
 add_library(toucan ${HEADERS} ${HEADERS_PRIVATE} ${SOURCE})
diff --git a/lib/toucan/CheckersOp.cpp b/lib/toucan/CheckersOp.cpp
index 55192ee..076318c 100644
--- a/lib/toucan/CheckersOp.cpp
+++ b/lib/toucan/CheckersOp.cpp
@@ -30,7 +30,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf CheckersOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf CheckersOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -40,7 +42,7 @@ namespace toucan
             {
                 offsetTime -= _timeOffset;
             }
-            buf = _inputs[0]->exec(offsetTime);
+            buf = _inputs[0]->exec(offsetTime, host);
             OIIO::ImageBufAlgo::checker(
                 buf,
                 _data.checkerSize.x,
diff --git a/lib/toucan/CheckersOp.h b/lib/toucan/CheckersOp.h
index 286828d..a4f1a1d 100644
--- a/lib/toucan/CheckersOp.h
+++ b/lib/toucan/CheckersOp.h
@@ -30,7 +30,9 @@ namespace toucan
         const CheckersData& getData() const;
         void setData(const CheckersData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         CheckersData _data;
diff --git a/lib/toucan/ColorMapOp.cpp b/lib/toucan/ColorMapOp.cpp
index f24dd43..24f6e5f 100644
--- a/lib/toucan/ColorMapOp.cpp
+++ b/lib/toucan/ColorMapOp.cpp
@@ -28,7 +28,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf ColorMapOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf ColorMapOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -39,7 +41,7 @@ namespace toucan
                 offsetTime -= _timeOffset;
             }
             buf = OIIO::ImageBufAlgo::color_map(
-                _inputs[0]->exec(offsetTime),
+                _inputs[0]->exec(offsetTime, host),
                 -1,
                 _data.mapName);
 
diff --git a/lib/toucan/ColorMapOp.h b/lib/toucan/ColorMapOp.h
index 020fd05..b83d9a3 100644
--- a/lib/toucan/ColorMapOp.h
+++ b/lib/toucan/ColorMapOp.h
@@ -27,7 +27,9 @@ namespace toucan
         const ColorMapData& getData() const;
         void setData(const ColorMapData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         ColorMapData _data;
diff --git a/lib/toucan/CompOp.cpp b/lib/toucan/CompOp.cpp
index 29ca2a2..a3ce1f8 100644
--- a/lib/toucan/CompOp.cpp
+++ b/lib/toucan/CompOp.cpp
@@ -20,7 +20,9 @@ namespace toucan
         _premult = premult;
     }
 
-    OIIO::ImageBuf CompOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf CompOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         OTIO_NS::RationalTime offsetTime = time;
@@ -30,8 +32,8 @@ namespace toucan
         }
         if (_inputs.size() > 1 && _inputs[0] && _inputs[1])
         {
-            auto fg = _inputs[0]->exec(offsetTime);
-            auto bg = _inputs[1]->exec(offsetTime);
+            auto fg = _inputs[0]->exec(offsetTime, host);
+            auto bg = _inputs[1]->exec(offsetTime, host);
             if (_premult)
             {
                 fg = OIIO::ImageBufAlgo::premult(fg);
@@ -40,7 +42,7 @@ namespace toucan
         }
         else if (1 == _inputs.size() && _inputs[0])
         {
-            auto fg = _inputs[0]->exec(offsetTime);
+            auto fg = _inputs[0]->exec(offsetTime, host);
             if (_premult)
             {
                 fg = OIIO::ImageBufAlgo::premult(fg);
diff --git a/lib/toucan/CompOp.h b/lib/toucan/CompOp.h
index f16dcac..948f94d 100644
--- a/lib/toucan/CompOp.h
+++ b/lib/toucan/CompOp.h
@@ -19,7 +19,9 @@ namespace toucan
         //! Set whether images are pre-multiplied before compositing.
         void setPremult(bool);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         bool _premult = false;
diff --git a/lib/toucan/FillOp.cpp b/lib/toucan/FillOp.cpp
index e295d56..99bc91a 100644
--- a/lib/toucan/FillOp.cpp
+++ b/lib/toucan/FillOp.cpp
@@ -30,7 +30,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf FillOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf FillOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -40,7 +42,7 @@ namespace toucan
             {
                 offsetTime -= _timeOffset;
             }
-            buf = _inputs[0]->exec(offsetTime);
+            buf = _inputs[0]->exec(offsetTime, host);
             OIIO::ImageBufAlgo::fill(
                 buf,
                 { _data.color.x, _data.color.y, _data.color.z, _data.color.w });
diff --git a/lib/toucan/FillOp.h b/lib/toucan/FillOp.h
index fa62c7a..5e010bd 100644
--- a/lib/toucan/FillOp.h
+++ b/lib/toucan/FillOp.h
@@ -28,7 +28,9 @@ namespace toucan
         const FillData& getData() const;
         void setData(const FillData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         FillData _data;
diff --git a/lib/toucan/FlipOp.cpp b/lib/toucan/FlipOp.cpp
index 837646b..5aed882 100644
--- a/lib/toucan/FlipOp.cpp
+++ b/lib/toucan/FlipOp.cpp
@@ -16,7 +16,9 @@ namespace toucan
     FlipOp::~FlipOp()
     {}
 
-    OIIO::ImageBuf FlipOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf FlipOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -26,7 +28,7 @@ namespace toucan
             {
                 offsetTime -= _timeOffset;
             }
-            const auto input = _inputs[0]->exec(offsetTime);
+            const auto input = _inputs[0]->exec(offsetTime, host);
             buf = OIIO::ImageBufAlgo::flip(input);
         }
         return buf;
diff --git a/lib/toucan/FlipOp.h b/lib/toucan/FlipOp.h
index 50ca070..49eda16 100644
--- a/lib/toucan/FlipOp.h
+++ b/lib/toucan/FlipOp.h
@@ -16,7 +16,9 @@ namespace toucan
 
         virtual ~FlipOp();
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
     };
 
     //! Flip OTIO effect.
diff --git a/lib/toucan/FlopOp.cpp b/lib/toucan/FlopOp.cpp
index fb56fd1..e87d9cd 100644
--- a/lib/toucan/FlopOp.cpp
+++ b/lib/toucan/FlopOp.cpp
@@ -16,7 +16,9 @@ namespace toucan
     FlopOp::~FlopOp()
     {}
 
-    OIIO::ImageBuf FlopOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf FlopOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -26,7 +28,7 @@ namespace toucan
             {
                 offsetTime -= _timeOffset;
             }
-            const auto input = _inputs[0]->exec(offsetTime);
+            const auto input = _inputs[0]->exec(offsetTime, host);
             buf = OIIO::ImageBufAlgo::flop(input);
         }
         return buf;
diff --git a/lib/toucan/FlopOp.h b/lib/toucan/FlopOp.h
index d17a011..94d2ffc 100644
--- a/lib/toucan/FlopOp.h
+++ b/lib/toucan/FlopOp.h
@@ -16,7 +16,9 @@ namespace toucan
 
         virtual ~FlopOp();
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
     };
 
     //! Flop OTIO effect.
diff --git a/lib/toucan/Host.cpp b/lib/toucan/Host.cpp
index 8844d5b..35681ec 100644
--- a/lib/toucan/Host.cpp
+++ b/lib/toucan/Host.cpp
@@ -15,6 +15,70 @@ namespace toucan
     {
         _propertySet.setPointer("host", 0, this);
 
+        _host.host = (OfxPropertySetHandle)&_propertySet;
+        _host.fetchSuite = &_fetchSuite;
+
+        _suiteInit();
+        _pluginInit(searchPath);
+    }
+
+    Host::~Host()
+    {
+        for (const auto& data : _pluginData)
+        {
+            OfxStatus ofxStatus = data.ofxPlugin->mainEntry(
+                kOfxActionUnload,
+                nullptr,
+                nullptr,
+                nullptr);
+        }
+    }
+
+    void Host::filter(
+        const std::string& name,
+        const OIIO::ImageBuf& source,
+        OIIO::ImageBuf& output,
+        const PropertySet& propSet)
+    {
+        for (auto& data : _pluginData)
+        {
+            if (name == data.ofxPlugin->pluginIdentifier)
+            {
+                OfxStatus ofxStatus = data.ofxPlugin->mainEntry(
+                    kOfxActionCreateInstance,
+                    &data,
+                    nullptr,
+                    nullptr);
+
+                data.images["Source"] = bufToPropSet(source);
+                data.images["Output"] = bufToPropSet(output);
+                PropertySet args;
+                args.setDouble(kOfxPropTime, 0, 0.0);
+                const auto& spec = source.spec();
+                OfxRectI bounds;
+                bounds.x1 = 0;
+                bounds.x2 = spec.width;
+                bounds.y1 = 0;
+                bounds.y2 = spec.height;
+                args.setIntN(kOfxImageEffectPropRenderWindow, 4, &bounds.x1);
+                ofxStatus = data.ofxPlugin->mainEntry(
+                    kOfxImageEffectActionRender,
+                    &data,
+                    (OfxPropertySetHandle)&args,
+                    nullptr);
+
+                ofxStatus = data.ofxPlugin->mainEntry(
+                    kOfxActionDestroyInstance,
+                    &data,
+                    nullptr,
+                    nullptr);
+                break;
+            }
+        }
+    }
+
+    void Host::_suiteInit()
+    {
         _propertySuite.propSetPointer = &PropertySet::setPointer;
         _propertySuite.propSetString = &PropertySet::setString;
         _propertySuite.propSetDouble = &PropertySet::setDouble;
@@ -35,49 +99,57 @@ namespace toucan
         _propertySuite.propGetDimension = &PropertySet::getDimension;
 
         _effectSuite.getPropertySet = &_getPropertySet;
+        _effectSuite.clipDefine = &_clipDefine;
+        _effectSuite.clipGetHandle = &_clipGetHandle;
+        _effectSuite.clipGetImage = &_clipGetImage;
+        _effectSuite.clipReleaseImage = &_clipReleaseImage;
+    }
 
-        _host.host = reinterpret_cast<OfxPropertySetHandle>(&_propertySet);
-        _host.fetchSuite = &_fetchSuite;
-
+    void Host::_pluginInit(const std::vector<std::filesystem::path>& searchPath)
+    {
+        // Find the plugins.
         std::vector<std::filesystem::path> pluginPaths;
         for (const auto& path : searchPath)
         {
             findPlugins(path, pluginPaths);
         }
-        for (auto const& path : pluginPaths)
+
+        // Load plugins.
+        for (const auto& path : pluginPaths)
         {
             //std::cout << path.string() << std::endl;
             try
             {
                 auto plugin = std::make_shared<Plugin>(path);
                 const int pluginCount = plugin->getCount();
-                //std::cout << "plugin count: " << pluginCount << std::endl;
-                if (pluginCount > 0)
+                for (int i = 0; i < pluginCount; ++i)
                 {
-                    OfxPlugin* ofxPlugin = plugin->getPlugin(0);
-                    //std::cout << "  plugin: " << ofxPlugin->pluginIdentifier << std::endl;
-                    ofxPlugin->setHost(&_host);
-                    OfxStatus ofxStatus = ofxPlugin->mainEntry(
-                        kOfxActionLoad,
-                        nullptr,
-                        nullptr,
-                        nullptr);
-                    switch (ofxStatus)
-                    {
-                    case kOfxStatOK:
-                    case kOfxStatReplyDefault:
-                        _plugins.push_back(plugin);
-                        break;
-                    case kOfxStatErrFatal:
+                    OfxPlugin* ofxPlugin = plugin->getPlugin(i);
+                    if (strcmp(ofxPlugin->pluginApi, kOfxImageEffectPluginApi) == 0)
                     {
-                        std::stringstream ss;
-                        ss << "Fatal error in plugin: " << path.string();
-                        throw std::runtime_error(ss.str());
-                        break;
-                    }
-                    case kOfxStatFailed:
-                    default:
-                        break;
+                        ofxPlugin->setHost(&_host);
+                        OfxStatus ofxStatus = ofxPlugin->mainEntry(
+                            kOfxActionLoad,
+                            nullptr,
+                            nullptr,
+                            nullptr);
+                        switch (ofxStatus)
+                        {
+                        case kOfxStatOK:
+                        case kOfxStatReplyDefault:
+                            _pluginData.push_back({ plugin, ofxPlugin });
+                            break;
+                        case kOfxStatErrFatal:
+                        {
+                            std::stringstream ss;
+                            ss << "Fatal error in plugin: " << path.string();
+                            throw std::runtime_error(ss.str());
+                            break;
+                        }
+                        case kOfxStatFailed:
+                        default:
+                            break;
+                        }
                     }
                 }
             }
@@ -87,32 +159,31 @@ namespace toucan
             }
         }
 
-        for (const auto& plugin : _plugins)
+        // Initialize plugins.
+        for (auto& data : _pluginData)
         {
-            OfxStatus ofxStatus = plugin->getPlugin(0)->mainEntry(
+            OfxStatus ofxStatus = data.ofxPlugin->mainEntry(
                 kOfxActionDescribe,
-                plugin.get(),
-                nullptr,
-                nullptr);
-            char* s = nullptr;
-            plugin->getPropertySet(0)->getString(kOfxPropLabel, 0, &s);
-            std::cout << "plugin: " << s << std::endl;
-            plugin->getPropertySet(0)->getString(kOfxImageEffectPluginPropGrouping, 0, &s);
-            std::cout << "    group: " << s << std::endl;
-            plugin->getPropertySet(0)->getString(kOfxImageEffectPropSupportedContexts, 0, &s);
-            std::cout << "    context: " << s << std::endl;
-        }
-    }
-
-    Host::~Host()
-    {
-        for (const auto& plugin : _plugins)
-        {
-            OfxStatus ofxStatus = plugin->getPlugin(0)->mainEntry(
-                kOfxActionUnload,
-                nullptr,
+                &data,
                 nullptr,
                 nullptr);
+            int contextCount = 0;
+            data.effectPropertySet.getDimension(kOfxImageEffectPropSupportedContexts, &contextCount);
+            for (int i = 0; i < contextCount; ++i)
+            {
+                char* context = nullptr;
+                data.effectPropertySet.getString(kOfxImageEffectPropSupportedContexts, i, &context);
+                if (context)
+                {
+                    PropertySet propertySet;
+                    propertySet.setString(kOfxImageEffectPropContext, 0, context);
+                    ofxStatus = data.ofxPlugin->mainEntry(
+                        kOfxImageEffectActionDescribeInContext,
+                        &data,
+                        (OfxPropertySetHandle)&propertySet,
+                        nullptr);
+                }
+            }
         }
     }
 
@@ -138,8 +209,37 @@ namespace toucan
     
     OfxStatus Host::_getPropertySet(OfxImageEffectHandle handle, OfxPropertySetHandle* propHandle)
     {
-        Plugin* plugin = reinterpret_cast<Plugin*>(handle);
-        *propHandle = reinterpret_cast<OfxPropertySetHandle>(plugin->getPropertySet(0));
+        PluginData* data = reinterpret_cast<PluginData*>(handle);
+        *propHandle = (OfxPropertySetHandle)&data->effectPropertySet;
+        return kOfxStatOK;
+    }
+    
+    OfxStatus Host::_clipDefine(OfxImageEffectHandle handle, const char* name, OfxPropertySetHandle* propHandle)
+    {
+        PluginData* data = reinterpret_cast<PluginData*>(handle);
+        *propHandle = (OfxPropertySetHandle)&data->clipPropertySets[name];
+        return kOfxStatOK;
+    }
+
+    OfxStatus Host::_clipGetHandle(OfxImageEffectHandle handle, const char* name, OfxImageClipHandle* clip, OfxPropertySetHandle* propHandle)
+    {
+        PluginData* data = reinterpret_cast<PluginData*>(handle);
+        *clip = (OfxImageClipHandle)&data->images[name];
+        if (propHandle)
+        {
+            *propHandle = (OfxPropertySetHandle)&data->clipPropertySets[name];
+        }
+        return kOfxStatOK;
+    }
+
+    OfxStatus Host::_clipGetImage(OfxImageClipHandle handle, OfxTime, const OfxRectD*, OfxPropertySetHandle* propHandle)
+    {
+        *propHandle = (OfxPropertySetHandle)handle;
+        return kOfxStatOK;
+    }
+
+    OfxStatus Host::_clipReleaseImage(OfxPropertySetHandle handle)
+    {
         return kOfxStatOK;
     }
 }
diff --git a/lib/toucan/Host.h b/lib/toucan/Host.h
index 666dcb1..c0b9e7a 100644
--- a/lib/toucan/Host.h
+++ b/lib/toucan/Host.h
@@ -9,6 +9,8 @@
 
 #include <OpenFX/ofxImageEffect.h>
 
+#include <OpenImageIO/imagebuf.h>
+
 #include <filesystem>
 #include <memory>
 
@@ -21,15 +23,35 @@ namespace toucan
 
         ~Host();
 
+        void filter(
+            const std::string& name,
+            const OIIO::ImageBuf&,
+            OIIO::ImageBuf&,
+            const PropertySet& = PropertySet());
+
     private:
-        static const void* _fetchSuite(OfxPropertySetHandle host, const char* suiteName, int suiteVersion);
+        void _suiteInit();
+        void _pluginInit(const std::vector<std::filesystem::path>& searchPath);
 
-        static OfxStatus _getPropertySet(OfxImageEffectHandle, OfxPropertySetHandle* propHandle);
+        static const void* _fetchSuite(OfxPropertySetHandle host, const char* suiteName, int suiteVersion);
+        static OfxStatus _getPropertySet(OfxImageEffectHandle, OfxPropertySetHandle*);
+        static OfxStatus _clipDefine(OfxImageEffectHandle, const char* name, OfxPropertySetHandle*);
+        static OfxStatus _clipGetHandle(OfxImageEffectHandle, const char* name, OfxImageClipHandle*, OfxPropertySetHandle*);
+        static OfxStatus _clipGetImage(OfxImageClipHandle, OfxTime, const OfxRectD*, OfxPropertySetHandle*);
+        static OfxStatus _clipReleaseImage(OfxPropertySetHandle);
 
         PropertySet _propertySet;
+        OfxHost _host;
         OfxPropertySuiteV1 _propertySuite;
         OfxImageEffectSuiteV1 _effectSuite;
-        OfxHost _host;
-        std::vector<std::shared_ptr<Plugin> > _plugins;
+        struct PluginData
+        {
+            std::shared_ptr<Plugin> plugin;
+            OfxPlugin* ofxPlugin = nullptr;
+            PropertySet effectPropertySet;
+            std::map<std::string, PropertySet> clipPropertySets;
+            std::map<std::string, PropertySet> images;
+        };
+        std::vector<PluginData> _pluginData;
     };
 }
diff --git a/lib/toucan/ImageOp.h b/lib/toucan/ImageOp.h
index 71f482c..6f42e00 100644
--- a/lib/toucan/ImageOp.h
+++ b/lib/toucan/ImageOp.h
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <toucan/Host.h>
+
 #include <opentimelineio/effect.h>
 
 #include <OpenImageIO/imagebuf.h>
@@ -27,7 +29,9 @@ namespace toucan
         void setTimeOffset(const OTIO_NS::RationalTime&);
 
         //! Execute the image operation for the given time.
-        virtual OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) = 0;
+        virtual OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) = 0;
 
     protected:
         OTIO_NS::RationalTime _timeOffset;
diff --git a/lib/toucan/InvertOp.cpp b/lib/toucan/InvertOp.cpp
index 1c21061..8c754b2 100644
--- a/lib/toucan/InvertOp.cpp
+++ b/lib/toucan/InvertOp.cpp
@@ -4,6 +4,8 @@
 
 #include "InvertOp.h"
 
+#include "PropertySet.h"
+
 #include <OpenImageIO/imagebufalgo.h>
 
 namespace toucan
@@ -16,7 +18,9 @@ namespace toucan
     InvertOp::~InvertOp()
     {}
 
-    OIIO::ImageBuf InvertOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf InvertOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -26,12 +30,10 @@ namespace toucan
             {
                 offsetTime -= _timeOffset;
             }
-            const auto input = _inputs[0]->exec(offsetTime);
-            auto roi = input.roi();
-            roi.chend = 3;
-            buf = OIIO::ImageBufAlgo::unpremult(input);
-            OIIO::ImageBufAlgo::invert(buf, buf, roi);
-            OIIO::ImageBufAlgo::repremult(buf, buf);
+            const auto input = _inputs[0]->exec(offsetTime, host);
+            const auto& spec = input.spec();
+            buf = OIIO::ImageBuf(spec);
+            host->filter("Toucan:Invert", input, buf);
         }
         return buf;
     }
diff --git a/lib/toucan/InvertOp.h b/lib/toucan/InvertOp.h
index dcdee06..b21052b 100644
--- a/lib/toucan/InvertOp.h
+++ b/lib/toucan/InvertOp.h
@@ -16,7 +16,9 @@ namespace toucan
 
         virtual ~InvertOp();
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
     };
 
     //! Invert OTIO effect.
diff --git a/lib/toucan/LineOp.cpp b/lib/toucan/LineOp.cpp
index 08dcfd4..5ff59b5 100644
--- a/lib/toucan/LineOp.cpp
+++ b/lib/toucan/LineOp.cpp
@@ -30,7 +30,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf LineOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf LineOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -40,7 +42,7 @@ namespace toucan
             {
                 offsetTime -= _timeOffset;
             }
-            buf = _inputs[0]->exec(offsetTime);
+            buf = _inputs[0]->exec(offsetTime, host);
             OIIO::ImageBufAlgo::render_line(
                 buf,
                 _data.pos1.x,
diff --git a/lib/toucan/LineOp.h b/lib/toucan/LineOp.h
index 4314919..bcbc323 100644
--- a/lib/toucan/LineOp.h
+++ b/lib/toucan/LineOp.h
@@ -30,7 +30,9 @@ namespace toucan
         const LineData& getData() const;
         void setData(const LineData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         LineData _data;
diff --git a/lib/toucan/LinearTimeWarpOp.cpp b/lib/toucan/LinearTimeWarpOp.cpp
index 304a350..2a29802 100644
--- a/lib/toucan/LinearTimeWarpOp.cpp
+++ b/lib/toucan/LinearTimeWarpOp.cpp
@@ -16,7 +16,9 @@ namespace toucan
     LinearTimeWarpOp::~LinearTimeWarpOp()
     {}
 
-    OIIO::ImageBuf LinearTimeWarpOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf LinearTimeWarpOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty())
@@ -27,7 +29,7 @@ namespace toucan
                 offsetTime -= _timeOffset;
             }
             const OTIO_NS::RationalTime scaledTime = OTIO_NS::RationalTime(offsetTime.value() * _timeScalar, offsetTime.rate()).floor();
-            buf = _inputs[0]->exec(scaledTime);
+            buf = _inputs[0]->exec(scaledTime, host);
         }
         return buf;
     }
diff --git a/lib/toucan/LinearTimeWarpOp.h b/lib/toucan/LinearTimeWarpOp.h
index e421264..2f44eed 100644
--- a/lib/toucan/LinearTimeWarpOp.h
+++ b/lib/toucan/LinearTimeWarpOp.h
@@ -18,7 +18,9 @@ namespace toucan
 
         virtual ~LinearTimeWarpOp();
         
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         float _timeScalar = 1.F;
diff --git a/lib/toucan/NoiseOp.cpp b/lib/toucan/NoiseOp.cpp
index edae31d..da1086e 100644
--- a/lib/toucan/NoiseOp.cpp
+++ b/lib/toucan/NoiseOp.cpp
@@ -28,7 +28,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf NoiseOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf NoiseOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -38,7 +40,7 @@ namespace toucan
             {
                 offsetTime -= _timeOffset;
             }
-            buf = _inputs[0]->exec(offsetTime);
+            buf = _inputs[0]->exec(offsetTime, host);
             OIIO::ImageBufAlgo::noise(
                 buf,
                 _data.type,
diff --git a/lib/toucan/NoiseOp.h b/lib/toucan/NoiseOp.h
index 6596c91..c11eec5 100644
--- a/lib/toucan/NoiseOp.h
+++ b/lib/toucan/NoiseOp.h
@@ -32,7 +32,9 @@ namespace toucan
         const NoiseData& getData() const;
         void setData(const NoiseData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         NoiseData _data;
diff --git a/lib/toucan/Plugin.cpp b/lib/toucan/Plugin.cpp
index ee8e6ae..e163184 100644
--- a/lib/toucan/Plugin.cpp
+++ b/lib/toucan/Plugin.cpp
@@ -4,85 +4,15 @@
 
 #include "Plugin.h"
 
-#include "Util.h"
-
-#include <OpenFX/ofxCore.h>
-
-#include <iostream>
-#include <sstream>
-
-#ifndef WIN32_LEAN_AND_MEAN
-#define WIN32_LEAN_AND_MEAN
-#endif // WIN32_LEAN_AND_MEAN
-#ifndef NOMINMAX
-#define NOMINMAX
-#endif // NOMINMAX
-#include <windows.h>
-
 namespace toucan
 {
-    namespace
-    {
-        typedef int(__cdecl* GetNumberOfPluginsFunc)(void);
-        typedef OfxPlugin* (__cdecl* GetPluginFunc)(int);
-        typedef void(__cdecl* SetHostFunc)(OfxHost*);
-        typedef OfxStatus (__cdecl* MainEntryPointFunc)(
-            const char*,
-            const void*,
-            OfxPropertySetHandle,
-            OfxPropertySetHandle);
-    }
-
-    struct Plugin::Private
-    {
-        HINSTANCE pluginInstance = nullptr;
-        GetNumberOfPluginsFunc getNumberOfPlugins = nullptr;
-        GetPluginFunc getPlugin = nullptr;
-    };
-
-    Plugin::Plugin(const std::filesystem::path& path) :
-        _p(new Private)
-    {
-        _p->pluginInstance = LoadLibrary(path.string().c_str());
-        if (!_p->pluginInstance)
-        {
-            std::stringstream ss;
-            ss << "Cannot load library: " << path.string();
-            throw std::runtime_error(ss.str());
-        }
-
-        _p->getNumberOfPlugins = (GetNumberOfPluginsFunc)GetProcAddress(
-            _p->pluginInstance,
-            "OfxGetNumberOfPlugins");
-        _p->getPlugin = (GetPluginFunc)GetProcAddress(
-            _p->pluginInstance,
-            "OfxGetPlugin");
-
-        if (_p->getNumberOfPlugins)
-        {
-            _effectPropertySets.resize(_p->getNumberOfPlugins());
-        }
-    }
-
-    Plugin::~Plugin()
-    {
-        FreeLibrary(_p->pluginInstance);
-    }
-
     int Plugin::getCount()
     {
-        return _p->getNumberOfPlugins ? _p->getNumberOfPlugins() : 0;
+        return _getNumberOfPlugins ? _getNumberOfPlugins() : 0;
     }
 
     OfxPlugin* Plugin::getPlugin(int index)
     {
-        return _p->getPlugin ? _p->getPlugin(index) : nullptr;
-    }
-
-    PropertySet* Plugin::getPropertySet(int index)
-    {
-        return index >= 0 && index  < _effectPropertySets.size() ?
-            &_effectPropertySets[index] :
-            nullptr;
+        return _getPlugin ? _getPlugin(index) : nullptr;
     }
 }
diff --git a/lib/toucan/Plugin.h b/lib/toucan/Plugin.h
index 3d2d2e3..21fedb2 100644
--- a/lib/toucan/Plugin.h
+++ b/lib/toucan/Plugin.h
@@ -24,10 +24,13 @@ namespace toucan
 
         OfxPlugin* getPlugin(int);
 
-        PropertySet* getPropertySet(int);
-
     private:
-        std::vector<PropertySet> _effectPropertySets;
+        typedef int(__cdecl* GetNumberOfPluginsFunc)(void);
+        GetNumberOfPluginsFunc _getNumberOfPlugins = nullptr;
+
+        typedef OfxPlugin* (__cdecl* GetPluginFunc)(int);
+        GetPluginFunc _getPlugin = nullptr;
+
         struct Private;
         std::unique_ptr<Private> _p;
     };
diff --git a/lib/toucan/PluginWin32.cpp b/lib/toucan/PluginWin32.cpp
new file mode 100644
index 0000000..9e63db5
--- /dev/null
+++ b/lib/toucan/PluginWin32.cpp
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (c) 2024 Darby Johnston
+// All rights reserved.
+
+#include "Plugin.h"
+
+#include "Util.h"
+
+#include <iostream>
+#include <sstream>
+
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif // WIN32_LEAN_AND_MEAN
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif // NOMINMAX
+#include <windows.h>
+
+namespace toucan
+{
+    struct Plugin::Private
+    {
+        HINSTANCE pluginInstance = nullptr;
+    };
+
+    Plugin::Plugin(const std::filesystem::path& path) :
+        _p(new Private)
+    {
+        _p->pluginInstance = LoadLibrary(path.string().c_str());
+        if (!_p->pluginInstance)
+        {
+            std::stringstream ss;
+            ss << "Cannot load library: " << path.string();
+            throw std::runtime_error(ss.str());
+        }
+
+        _getNumberOfPlugins = (GetNumberOfPluginsFunc)GetProcAddress(
+            _p->pluginInstance,
+            "OfxGetNumberOfPlugins");
+        _getPlugin = (GetPluginFunc)GetProcAddress(
+            _p->pluginInstance,
+            "OfxGetPlugin");
+    }
+
+    Plugin::~Plugin()
+    {
+        FreeLibrary(_p->pluginInstance);
+    }
+}
diff --git a/lib/toucan/PowOp.cpp b/lib/toucan/PowOp.cpp
index 9fda367..86d9d79 100644
--- a/lib/toucan/PowOp.cpp
+++ b/lib/toucan/PowOp.cpp
@@ -28,7 +28,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf PowOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf PowOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -39,7 +41,7 @@ namespace toucan
                 offsetTime -= _timeOffset;
             }
             buf = OIIO::ImageBufAlgo::pow(
-                _inputs[0]->exec(offsetTime),
+                _inputs[0]->exec(offsetTime, host),
                 _data.value);
         }
         return buf;
diff --git a/lib/toucan/PowOp.h b/lib/toucan/PowOp.h
index 9704c25..e4a51df 100644
--- a/lib/toucan/PowOp.h
+++ b/lib/toucan/PowOp.h
@@ -27,7 +27,9 @@ namespace toucan
         const PowData& getData() const;
         void setData(const PowData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         PowData _data;
diff --git a/lib/toucan/PropertySet.cpp b/lib/toucan/PropertySet.cpp
index 29cad7a..b9063d0 100644
--- a/lib/toucan/PropertySet.cpp
+++ b/lib/toucan/PropertySet.cpp
@@ -4,6 +4,8 @@
 
 #include "PropertySet.h"
 
+#include <OpenFX/ofxImageEffect.h>
+
 namespace toucan
 {
     OfxStatus PropertySet::setPointer(const char* property, int index, void* value)
@@ -52,21 +54,45 @@ namespace toucan
 
     OfxStatus PropertySet::setPointerN(const char* property, int count, void* const* value)
     {
+        auto& v = _p[property];
+        v.resize(count);
+        for (int i = 0; i < count; ++i)
+        {
+            v[i] = value[i];
+        }
         return kOfxStatOK;
     }
 
     OfxStatus PropertySet::setStringN(const char* property, int count, const char* const* value)
     {
+        auto& v = _s[property];
+        v.resize(count);
+        for (int i = 0; i < count; ++i)
+        {
+            v[i] = value[i];
+        }
         return kOfxStatOK;
     }
 
     OfxStatus PropertySet::setDoubleN(const char* property, int count, const double* value)
     {
+        auto& v = _d[property];
+        v.resize(count);
+        for (int i = 0; i < count; ++i)
+        {
+            v[i] = value[i];
+        }
         return kOfxStatOK;
     }
 
     OfxStatus PropertySet::setIntN(const char* property, int count, const int* value)
     {
+        auto& v = _i[property];
+        v.resize(count);
+        for (int i = 0; i < count; ++i)
+        {
+            v[i] = value[i];
+        }
         return kOfxStatOK;
     }
 
@@ -95,10 +121,11 @@ namespace toucan
             {
                 const auto& string = v[index];
                 const size_t size = string.size();
-                _sBuf.resize(size + 1);
-                memcpy(_sBuf.data(), string.c_str(), size);
-                _sBuf[size] = 0;
-                *value = _sBuf.data();
+                _buf.resize(1);
+                _buf[0].resize(size + 1);
+                memcpy(_buf[0].data(), string.c_str(), size);
+                _buf[0][size] = 0;
+                *value = _buf[0].data();
                 return kOfxStatOK;
             }
         }
@@ -107,32 +134,109 @@ namespace toucan
 
     OfxStatus PropertySet::getDouble(const char* property, int index, double* value)
     {
-        return kOfxStatOK;
+        auto d = _d.find(property);
+        if (d != _d.end())
+        {
+            const auto& v = d->second;
+            if (index < v.size())
+            {
+                *value = v[index];
+                return kOfxStatOK;
+            }
+        }
+        return kOfxStatFailed;
     }
 
     OfxStatus PropertySet::getInt(const char* property, int index, int* value)
     {
-        return kOfxStatOK;
+        auto i = _i.find(property);
+        if (i != _i.end())
+        {
+            const auto& v = i->second;
+            if (index < v.size())
+            {
+                *value = v[index];
+                return kOfxStatOK;
+            }
+        }
+        return kOfxStatFailed;
     }
 
     OfxStatus PropertySet::getPointerN(const char* property, int count, void** value)
     {
-        return kOfxStatOK;
+        auto p = _p.find(property);
+        if (p != _p.end())
+        {
+            const auto& v = p->second;
+            if (count == v.size())
+            {
+                for (int i = 0; i < count; ++i)
+                {
+                    value[i] = v[i];
+                }
+                return kOfxStatOK;
+            }
+        }
+        return kOfxStatFailed;
     }
 
     OfxStatus PropertySet::getStringN(const char* property, int count, char** value)
     {
-        return kOfxStatOK;
+        auto s = _s.find(property);
+        if (s != _s.end())
+        {
+            const auto& v = s->second;
+            if (count == v.size())
+            {
+                _buf.resize(count);
+                for (int i = 0; i < count; ++i)
+                {
+                    const size_t size = v[i].size();
+                    _buf[i].resize(size + 1);
+                    memcpy(_buf[i].data(), v[i].c_str(), size);
+                    _buf[i][size] = 0;
+                    value[i] = _buf[i].data();
+                }
+                return kOfxStatOK;
+            }
+        }
+        return kOfxStatFailed;
     }
 
     OfxStatus PropertySet::getDoubleN(const char* property, int count, double* value)
     {
-        return kOfxStatOK;
+        auto d = _d.find(property);
+        if (d != _d.end())
+        {
+            const auto& v = d->second;
+            if (count == v.size())
+            {
+                for (int i = 0; i < count; ++i)
+                {
+                    value[i] = v[i];
+                }
+                return kOfxStatOK;
+            }
+        }
+        return kOfxStatFailed;
     }
 
     OfxStatus PropertySet::getIntN(const char* property, int count, int* value)
     {
-        return kOfxStatOK;
+        auto i = _i.find(property);
+        if (i != _i.end())
+        {
+            const auto& v = i->second;
+            if (count == v.size())
+            {
+                for (int i = 0; i < count; ++i)
+                {
+                    value[i] = v[i];
+                }
+                return kOfxStatOK;
+            }
+        }
+        return kOfxStatFailed;
     }
 
     OfxStatus PropertySet::reset(const char* property)
@@ -284,4 +388,46 @@ namespace toucan
     {
         return reinterpret_cast<PropertySet*>(handle)->getDimension(property, count);
     }
+
+    PropertySet bufToPropSet(const OIIO::ImageBuf& buf)
+    {
+        PropertySet out;
+
+        const auto& spec = buf.spec();
+        OfxRectI bounds;
+        bounds.x1 = 0;
+        bounds.x2 = spec.width;
+        bounds.y1 = 0;
+        bounds.y2 = spec.height;
+        out.setIntN(kOfxImagePropBounds, 4, &bounds.x1);
+
+        std::string components;
+        switch (spec.nchannels)
+        {
+        case 1: components = kOfxImageComponentAlpha; break;
+        case 3: components = kOfxImageComponentRGB; break;
+        case 4: components = kOfxImageComponentRGBA; break;
+        }
+        out.setString(kOfxImageEffectPropComponents, 0, components.c_str());
+
+        std::string pixelDepth;
+        if (OIIO::TypeDesc::UINT8 == spec.format)
+        {
+            pixelDepth = kOfxBitDepthByte;
+        }
+        else if (OIIO::TypeDesc::UINT16 == spec.format)
+        {
+            pixelDepth = kOfxBitDepthShort;
+        }
+        else if (OIIO::TypeDesc::FLOAT == spec.format)
+        {
+            pixelDepth = kOfxBitDepthFloat;
+        }
+
+        out.setString(kOfxImageEffectPropPixelDepth, 0, pixelDepth.c_str());
+        out.setInt(kOfxImagePropRowBytes, 0, spec.scanline_bytes());
+        out.setPointer(kOfxImagePropData, 0, (void*)buf.localpixels());
+
+        return out;
+    }
 }
diff --git a/lib/toucan/PropertySet.h b/lib/toucan/PropertySet.h
index 9caf92c..88ea2f8 100644
--- a/lib/toucan/PropertySet.h
+++ b/lib/toucan/PropertySet.h
@@ -6,12 +6,15 @@
 
 #include <OpenFX/ofxProperty.h>
 
+#include <OpenImageIO/imagebuf.h>
+
 #include <map>
 #include <string>
 #include <vector>
 
 namespace toucan
 {
+    //! Container class for OpenFX values.
     class PropertySet
     {
     public:
@@ -56,9 +59,11 @@ namespace toucan
     private:
         std::map<std::string, std::vector<void*> > _p;
         std::map<std::string, std::vector<std::string> > _s;
-        std::vector<char> _sBuf;
+        std::vector<std::vector<char> > _buf;
         std::map<std::string, std::vector<double> > _d;
         std::map<std::string, std::vector<int> > _i;
     };
 
+    //! Convert to a property set.
+    PropertySet bufToPropSet(const OIIO::ImageBuf&);
 }
diff --git a/lib/toucan/ReadOp.cpp b/lib/toucan/ReadOp.cpp
index 3d50464..7cfcde3 100644
--- a/lib/toucan/ReadOp.cpp
+++ b/lib/toucan/ReadOp.cpp
@@ -18,7 +18,9 @@ namespace toucan
     ReadOp::~ReadOp()
     {}
 
-    OIIO::ImageBuf ReadOp::exec(const OTIO_NS::RationalTime&)
+    OIIO::ImageBuf ReadOp::exec(
+        const OTIO_NS::RationalTime&,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf(_path.string());
         const auto& spec = buf.spec();
diff --git a/lib/toucan/ReadOp.h b/lib/toucan/ReadOp.h
index 3b17a2c..346c7a9 100644
--- a/lib/toucan/ReadOp.h
+++ b/lib/toucan/ReadOp.h
@@ -20,7 +20,9 @@ namespace toucan
 
         virtual ~ReadOp();
         
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         std::filesystem::path _path;
diff --git a/lib/toucan/ResizeOp.cpp b/lib/toucan/ResizeOp.cpp
index dee5c00..378630a 100644
--- a/lib/toucan/ResizeOp.cpp
+++ b/lib/toucan/ResizeOp.cpp
@@ -28,7 +28,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf ResizeOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf ResizeOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -39,7 +41,7 @@ namespace toucan
                 offsetTime -= _timeOffset;
             }
             buf = OIIO::ImageBufAlgo::resize(
-                _inputs[0]->exec(offsetTime),
+                _inputs[0]->exec(offsetTime, host),
                 _data.filterName,
                 _data.filterWidth,
                 OIIO::ROI(0, _data.size.x, 0, _data.size.y, 0, 1, 0, 4));
diff --git a/lib/toucan/ResizeOp.h b/lib/toucan/ResizeOp.h
index d76cefa..506d36f 100644
--- a/lib/toucan/ResizeOp.h
+++ b/lib/toucan/ResizeOp.h
@@ -29,7 +29,9 @@ namespace toucan
         const ResizeData& getData() const;
         void setData(const ResizeData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         ResizeData _data;
diff --git a/lib/toucan/RotateOp.cpp b/lib/toucan/RotateOp.cpp
index 990203a..edef7b8 100644
--- a/lib/toucan/RotateOp.cpp
+++ b/lib/toucan/RotateOp.cpp
@@ -28,7 +28,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf RotateOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf RotateOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -39,7 +41,7 @@ namespace toucan
                 offsetTime -= _timeOffset;
             }
             buf = OIIO::ImageBufAlgo::rotate(
-                _inputs[0]->exec(offsetTime),
+                _inputs[0]->exec(offsetTime, host),
                 _data.angle / 360.F * 2.F * M_PI,
                 _data.filterName,
                 _data.filterWidth);
diff --git a/lib/toucan/RotateOp.h b/lib/toucan/RotateOp.h
index 35e17c5..dfd1a21 100644
--- a/lib/toucan/RotateOp.h
+++ b/lib/toucan/RotateOp.h
@@ -29,7 +29,9 @@ namespace toucan
         const RotateData& getData() const;
         void setData(const RotateData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         RotateData _data;
diff --git a/lib/toucan/SaturateOp.cpp b/lib/toucan/SaturateOp.cpp
index cb6b7ab..23fecdf 100644
--- a/lib/toucan/SaturateOp.cpp
+++ b/lib/toucan/SaturateOp.cpp
@@ -28,7 +28,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf SaturateOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf SaturateOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -39,7 +41,7 @@ namespace toucan
                 offsetTime -= _timeOffset;
             }
             buf = OIIO::ImageBufAlgo::saturate(
-                _inputs[0]->exec(offsetTime),
+                _inputs[0]->exec(offsetTime, host),
                 _data.value);
         }
         return buf;
diff --git a/lib/toucan/SaturateOp.h b/lib/toucan/SaturateOp.h
index 1bf62a5..9d6f8f9 100644
--- a/lib/toucan/SaturateOp.h
+++ b/lib/toucan/SaturateOp.h
@@ -27,7 +27,9 @@ namespace toucan
         const SaturateData& getData() const;
         void setData(const SaturateData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         SaturateData _data;
diff --git a/lib/toucan/SequenceReadOp.cpp b/lib/toucan/SequenceReadOp.cpp
index 618d299..0be58a6 100644
--- a/lib/toucan/SequenceReadOp.cpp
+++ b/lib/toucan/SequenceReadOp.cpp
@@ -33,7 +33,9 @@ namespace toucan
     SequenceReadOp::~SequenceReadOp()
     {}
 
-    OIIO::ImageBuf SequenceReadOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf SequenceReadOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OTIO_NS::RationalTime offsetTime = time;
         if (!_timeOffset.is_invalid_time())
diff --git a/lib/toucan/SequenceReadOp.h b/lib/toucan/SequenceReadOp.h
index fa1bb5f..db4d6d4 100644
--- a/lib/toucan/SequenceReadOp.h
+++ b/lib/toucan/SequenceReadOp.h
@@ -26,7 +26,9 @@ namespace toucan
 
         virtual ~SequenceReadOp();
         
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         std::filesystem::path _base;
diff --git a/lib/toucan/TextOp.cpp b/lib/toucan/TextOp.cpp
index ff4bc50..6f86677 100644
--- a/lib/toucan/TextOp.cpp
+++ b/lib/toucan/TextOp.cpp
@@ -30,7 +30,9 @@ namespace toucan
         _data = value;
     }
 
-    OIIO::ImageBuf TextOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf TextOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (!_inputs.empty() && _inputs[0])
@@ -40,7 +42,7 @@ namespace toucan
             {
                 offsetTime -= _timeOffset;
             }
-            buf = _inputs[0]->exec(offsetTime);
+            buf = _inputs[0]->exec(offsetTime, host);
             OIIO::ImageBufAlgo::render_text(
                 buf,
                 _data.pos.x,
diff --git a/lib/toucan/TextOp.h b/lib/toucan/TextOp.h
index 7b7716c..55e82c7 100644
--- a/lib/toucan/TextOp.h
+++ b/lib/toucan/TextOp.h
@@ -31,7 +31,9 @@ namespace toucan
         const TextData& getData() const;
         void setData(const TextData&);
 
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         TextData _data;
diff --git a/lib/toucan/TimelineTraverse.cpp b/lib/toucan/TimelineTraverse.cpp
index 0c37cdf..3ca021b 100644
--- a/lib/toucan/TimelineTraverse.cpp
+++ b/lib/toucan/TimelineTraverse.cpp
@@ -31,8 +31,7 @@ namespace toucan
             {
                 const std::string url = externalRef->target_url();
                 const std::filesystem::path path = _path / url;
-                auto read = std::make_shared<ReadOp>(path);
-                const auto buf = read->exec(OTIO_NS::RationalTime(0.0, 1.0));
+                const OIIO::ImageBuf buf(path.string());
                 const auto& spec = buf.spec();
                 if (spec.width > 0)
                 {
@@ -45,15 +44,12 @@ namespace toucan
             {
                 const std::string url = sequenceRef->target_url_base();
                 const std::filesystem::path path = _path / url;
-                auto read = std::make_shared<SequenceReadOp>(
-                    path.string(),
-                    sequenceRef->name_prefix(),
-                    sequenceRef->name_suffix(),
-                    sequenceRef->start_frame(),
-                    sequenceRef->frame_step(),
-                    sequenceRef->rate(),
-                    sequenceRef->frame_zero_padding());
-                const auto buf = read->exec(OTIO_NS::RationalTime(0.0, 1.0));
+                std::stringstream ss;
+                ss << path.string() <<
+                    sequenceRef->name_prefix() <<
+                    std::setw(sequenceRef->frame_zero_padding()) << std::setfill('0') << sequenceRef->start_frame() <<
+                    sequenceRef->name_suffix();
+                const OIIO::ImageBuf buf(ss.str());
                 const auto& spec = buf.spec();
                 if (spec.width > 0)
                 {
diff --git a/lib/toucan/TransitionOp.cpp b/lib/toucan/TransitionOp.cpp
index 729c16c..16f8e7a 100644
--- a/lib/toucan/TransitionOp.cpp
+++ b/lib/toucan/TransitionOp.cpp
@@ -20,7 +20,9 @@ namespace toucan
     TransitionOp::~TransitionOp()
     {}
 
-    OIIO::ImageBuf TransitionOp::exec(const OTIO_NS::RationalTime& time)
+    OIIO::ImageBuf TransitionOp::exec(
+        const OTIO_NS::RationalTime& time,
+        const std::shared_ptr<Host>& host)
     {
         OIIO::ImageBuf buf;
         if (_inputs.size() > 1 && _inputs[0] && _inputs[1])
@@ -31,8 +33,8 @@ namespace toucan
                 offsetTime -= _timeOffset;
             }
 
-            const auto a = _inputs[0]->exec(offsetTime);
-            const auto b = _inputs[1]->exec(offsetTime);
+            const auto a = _inputs[0]->exec(offsetTime, host);
+            const auto b = _inputs[1]->exec(offsetTime, host);
             
             const float v =
                 (offsetTime.rescaled_to(_range.duration().rate()) - _range.start_time()).value() /
diff --git a/lib/toucan/TransitionOp.h b/lib/toucan/TransitionOp.h
index 61302f0..60545ca 100644
--- a/lib/toucan/TransitionOp.h
+++ b/lib/toucan/TransitionOp.h
@@ -18,7 +18,9 @@ namespace toucan
 
         virtual ~TransitionOp();
         
-        OIIO::ImageBuf exec(const OTIO_NS::RationalTime&) override;
+        OIIO::ImageBuf exec(
+            const OTIO_NS::RationalTime&,
+            const std::shared_ptr<Host>&) override;
 
     private:
         OTIO_NS::TimeRange _range;
diff --git a/lib/toucan/Util.cpp b/lib/toucan/Util.cpp
index 9866b9f..de1dbab 100644
--- a/lib/toucan/Util.cpp
+++ b/lib/toucan/Util.cpp
@@ -4,6 +4,8 @@
 
 #include "Util.h"
 
+#include <OpenFX/ofxImageEffect.h>
+
 namespace toucan
 {
     namespace
diff --git a/lib/toucan/Util.h b/lib/toucan/Util.h
index 22d04e0..d83afa6 100644
--- a/lib/toucan/Util.h
+++ b/lib/toucan/Util.h
@@ -4,6 +4,10 @@
 
 #pragma once
 
+#include <toucan/PropertySet.h>
+
+#include <OpenFX/ofxProperty.h>
+
 #include <opentimelineio/anyVector.h>
 
 #include <Imath/ImathVec.h>
diff --git a/plugins/CMakeLists.txt b/plugins/CMakeLists.txt
index 08ec719..a1927a7 100644
--- a/plugins/CMakeLists.txt
+++ b/plugins/CMakeLists.txt
@@ -1,7 +1,9 @@
 set(HEADERS
-    InvertPlugin.h)
+    InvertPlugin.h
+    Util.h)
 set(SOURCE
-    InvertPlugin.cpp)
+    InvertPlugin.cpp
+    Util.cpp)
 
 add_library(toucan-invert MODULE ${HEADERS} ${SOURCE})
 target_link_libraries(toucan-invert PUBLIC OpenImageIO::OpenImageIO)
diff --git a/plugins/InvertPlugin.cpp b/plugins/InvertPlugin.cpp
index 2d3bcb5..1fa3b69 100644
--- a/plugins/InvertPlugin.cpp
+++ b/plugins/InvertPlugin.cpp
@@ -4,8 +4,12 @@
 
 #include "InvertPlugin.h"
 
+#include "Util.h"
+
 #include <OpenFX/ofxImageEffect.h>
 
+#include <OpenImageIO/imagebufalgo.h>
+
 #include <iostream>
 
 namespace
@@ -17,7 +21,7 @@ namespace
     {
         kOfxImageEffectPluginApi,
         1,
-        "toucan:invert",
+        "Toucan:Invert",
         1,
         0,
         SetHostFunc,
@@ -75,12 +79,12 @@ extern "C"
             effectProps,
             kOfxPropLabel,
             0,
-            "invert");
+            "Invert");
         propertySuite->propSetString(
             effectProps,
             kOfxImageEffectPluginPropGrouping,
             0,
-            "toucan");
+            "Toucan");
         propertySuite->propSetString(
             effectProps,
             kOfxImageEffectPropSupportedContexts,
@@ -89,6 +93,116 @@ extern "C"
         return kOfxStatOK;
     }
 
+    OfxStatus DescribeInContextAction(OfxImageEffectHandle descriptor, OfxPropertySetHandle inArgs)
+    {
+        OfxPropertySetHandle sourceProps;
+        OfxPropertySetHandle outputProps;
+        imageEffectSuite->clipDefine(descriptor, "Source", &sourceProps);
+        imageEffectSuite->clipDefine(descriptor, "Output", &outputProps);
+        const std::vector<std::string> components =
+        {
+            kOfxImageComponentAlpha,
+            kOfxImageComponentRGB,
+            kOfxImageComponentRGBA
+        };
+        const std::vector<std::string> pixelDepths =
+        {
+            kOfxBitDepthByte,
+            kOfxBitDepthShort,
+            kOfxBitDepthFloat
+        };
+        for (int i = 0; i < components.size(); ++i)
+        {
+            propertySuite->propSetString(
+                sourceProps,
+                kOfxImageEffectPropSupportedComponents,
+                i,
+                components[i].c_str());
+            propertySuite->propSetString(
+                outputProps,
+                kOfxImageEffectPropSupportedComponents,
+                i,
+                components[i].c_str());
+        }
+        for (int i = 0; i < pixelDepths.size(); ++i)
+        {
+            propertySuite->propSetString(
+                sourceProps,
+                kOfxImageEffectPropSupportedPixelDepths,
+                i,
+                pixelDepths[i].c_str());
+            propertySuite->propSetString(
+                outputProps,
+                kOfxImageEffectPropSupportedPixelDepths,
+                i,
+                pixelDepths[i].c_str());
+        }
+        return kOfxStatOK;
+    }
+
+    OfxStatus RenderAction(
+        OfxImageEffectHandle instance,
+        OfxPropertySetHandle inArgs,
+        OfxPropertySetHandle outArgs)
+    {
+        OfxTime time;
+        OfxRectI renderWindow;
+        propertySuite->propGetDouble(inArgs, kOfxPropTime, 0, &time);
+        propertySuite->propGetIntN(inArgs, kOfxImageEffectPropRenderWindow, 4, &renderWindow.x1);
+
+        OfxImageClipHandle sourceClip = nullptr;
+        OfxImageClipHandle outputClip = nullptr;
+        OfxPropertySetHandle sourceImage = nullptr;
+        OfxPropertySetHandle outputImage = nullptr;
+        imageEffectSuite->clipGetHandle(instance, "Source", &sourceClip, nullptr);
+        imageEffectSuite->clipGetHandle(instance, "Output", &outputClip, nullptr);
+        if (sourceClip && outputClip)
+        {
+            imageEffectSuite->clipGetImage(sourceClip, time, nullptr, &sourceImage);
+            imageEffectSuite->clipGetImage(outputClip, time, nullptr, &outputImage);
+            if (sourceImage && outputImage)
+            {
+                const OIIO::ImageBuf sourceBuf = propSetToBuf(propertySuite, sourceImage);
+                OIIO::ImageBuf outputBuf = propSetToBuf(propertySuite, outputImage);
+                OIIO::ImageBufAlgo::invert(
+                    outputBuf,
+                    sourceBuf,
+                    OIIO::ROI(
+                        renderWindow.x1,
+                        renderWindow.x2,
+                        renderWindow.y1,
+                        renderWindow.y2,
+                        0,
+                        1,
+                        0,
+                        3));
+                OIIO::ImageBufAlgo::copy(
+                    outputBuf,
+                    sourceBuf,
+                    OIIO::TypeUnknown,
+                    OIIO::ROI(
+                        renderWindow.x1,
+                        renderWindow.x2,
+                        renderWindow.y1,
+                        renderWindow.y2,
+                        0,
+                        1,
+                        3,
+                        4));
+            }
+        }
+
+        if (sourceImage)
+        {
+            imageEffectSuite->clipReleaseImage(sourceImage);
+        }
+        if (outputImage)
+        {
+            imageEffectSuite->clipReleaseImage(outputImage);
+        }
+        return kOfxStatOK;
+    }
+
     OfxStatus MainEntryPoint(
         const char* action,
         const void* handle,
@@ -97,6 +211,7 @@ extern "C"
     {
         OfxStatus out = kOfxStatReplyDefault;
         //std::cout << "MainEntryPoint: " << action << std::endl;
+        OfxImageEffectHandle effectHandle = (OfxImageEffectHandle)handle;
         if (strcmp(action, kOfxActionLoad) == 0)
         {
             out = LoadAction();
@@ -107,7 +222,15 @@ extern "C"
         }
         else if (strcmp(action, kOfxActionDescribe) == 0)
         {
-            out = DescribeAction((OfxImageEffectHandle)handle);
+            out = DescribeAction(effectHandle);
+        }
+        else if (strcmp(action, kOfxImageEffectActionDescribeInContext) == 0)
+        {
+            out = DescribeInContextAction(effectHandle, inArgs);
+        }
+        else if (strcmp(action, kOfxImageEffectActionRender) == 0)
+        {
+            out = RenderAction(effectHandle, inArgs, outArgs);
         }
         return out;
     }
diff --git a/plugins/Util.cpp b/plugins/Util.cpp
new file mode 100644
index 0000000..a10a9f2
--- /dev/null
+++ b/plugins/Util.cpp
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (c) 2024 Darby Johnston
+// All rights reserved.
+
+#include "Util.h"
+
+#include <OpenFX/ofxImageEffect.h>
+
+OIIO::ImageBuf propSetToBuf(OfxPropertySuiteV1* suite, OfxPropertySetHandle handle)
+{
+    OfxRectI bounds;
+    suite->propGetIntN(handle, kOfxImagePropBounds, 4, &bounds.x1);
+
+    int components = 0;
+    char* s = nullptr;
+    suite->propGetString(handle, kOfxImageEffectPropComponents, 0, &s);
+    if (strcmp(s, kOfxImageComponentAlpha) == 0)
+    {
+        components = 1;
+    }
+    else if (strcmp(s, kOfxImageComponentRGB) == 0)
+    {
+        components = 3;
+    }
+    else if (strcmp(s, kOfxImageComponentRGBA) == 0)
+    {
+        components = 4;
+    }
+
+    int pixelDepth = 0;
+    suite->propGetString(handle, kOfxImageEffectPropPixelDepth, 0, &s);
+    if (strcmp(s, kOfxBitDepthByte) == 0)
+    {
+        pixelDepth = 1;
+    }
+    else if (strcmp(s, kOfxBitDepthShort) == 0)
+    {
+        pixelDepth = 2;
+    }
+    else if (strcmp(s, kOfxBitDepthFloat) == 0)
+    {
+        pixelDepth = 4;
+    }
+
+    int rowBytes = 0;
+    suite->propGetInt(handle, kOfxImagePropRowBytes, 0, &rowBytes);
+
+    void* p = nullptr;
+    suite->propGetPointer(handle, kOfxImagePropData, 0, &p);
+
+    OIIO::ImageSpec spec;
+    spec.width = bounds.x2 - bounds.x1;
+    spec.height = bounds.y2 - bounds.y1;
+    spec.nchannels = components;
+    switch (pixelDepth)
+    {
+    case 1: spec.format = OIIO::TypeDesc::UINT8; break;
+    case 2: spec.format = OIIO::TypeDesc::UINT16; break;
+    case 4: spec.format = OIIO::TypeDesc::FLOAT; break;
+    default: break;
+    }
+
+    return OIIO::ImageBuf(
+        spec,
+        p,
+        components * pixelDepth,
+        rowBytes,
+        0);
+}
diff --git a/plugins/Util.h b/plugins/Util.h
new file mode 100644
index 0000000..f00bf97
--- /dev/null
+++ b/plugins/Util.h
@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (c) 2024 Darby Johnston
+// All rights reserved.
+
+#pragma once
+
+#include <OpenFX/ofxProperty.h>
+
+#include <OpenImageIO/imagebuf.h>
+
+//! Convert from a property set.
+OIIO::ImageBuf propSetToBuf(OfxPropertySuiteV1*, OfxPropertySetHandle);
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 2a7b487..7013428 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -1,11 +1,13 @@
 set(HEADERS
     CompOpTest.h
+    PropertySetTest.h
     ReadOpTest.h
     TimelineTraverseTest.h
     UtilTest.h)
 
 set(SOURCE
     CompOpTest.cpp
+    PropertySetTest.cpp
     ReadOpTest.cpp
     TimelineTraverseTest.cpp
     UtilTest.cpp
diff --git a/tests/CompOpTest.cpp b/tests/CompOpTest.cpp
index ec8c4c3..93a46a3 100644
--- a/tests/CompOpTest.cpp
+++ b/tests/CompOpTest.cpp
@@ -9,7 +9,9 @@
 
 namespace toucan
 {
-    void compOpTest(const std::filesystem::path& path)
+    void compOpTest(
+        const std::filesystem::path& path,
+        const std::shared_ptr<Host>& host)
     {
         std::cout << "compOpTest" << std::endl;
         auto fg = std::make_shared<ReadOp>(path / "Letter_A.png");
@@ -17,7 +19,7 @@ namespace toucan
         auto comp = std::make_shared<CompOp>(
             std::vector<std::shared_ptr<IImageOp> >{ fg, bg });
         comp->setPremult(true);
-        auto buf = comp->exec(OTIO_NS::RationalTime());
+        auto buf = comp->exec(OTIO_NS::RationalTime(), host);
         buf.write("compOpTest.png");
     }
 }
diff --git a/tests/CompOpTest.h b/tests/CompOpTest.h
index c11a6ad..3d23ed2 100644
--- a/tests/CompOpTest.h
+++ b/tests/CompOpTest.h
@@ -4,9 +4,11 @@
 
 #pragma once
 
-#include <filesystem>
+#include <toucan/Host.h>
 
 namespace toucan
 {
-    void compOpTest(const std::filesystem::path&);
+    void compOpTest(
+        const std::filesystem::path&,
+        const std::shared_ptr<Host>&);
 }
diff --git a/tests/PropertySetTest.cpp b/tests/PropertySetTest.cpp
new file mode 100644
index 0000000..5def72e
--- /dev/null
+++ b/tests/PropertySetTest.cpp
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (c) 2024 Darby Johnston
+// All rights reserved.
+
+#include "PropertySetTest.h"
+
+#include <toucan/PropertySet.h>
+
+#include <cassert>
+
+namespace toucan
+{
+    void propertySetTest()
+    {
+        {
+            int a = 1;
+            PropertySet p;
+            p.setPointer("p", 0, &a);
+            int* b = nullptr;
+            p.getPointer("p", 0, (void**)&b);
+            assert(b);
+            assert(b == &a);
+        }
+        {
+            std::string a = "a";
+            PropertySet p;
+            p.setString("s", 0, a.c_str());
+            char* b = nullptr;
+            p.getString("s", 0, &b);
+            assert(b);
+            assert(b == a);
+        }
+        {
+            double a = 1.0;
+            PropertySet p;
+            p.setDouble("d", 0, a);
+            double b = 0.0;
+            p.getDouble("d", 0, &b);
+            assert(b);
+            assert(b == a);
+        }
+        {
+            int a = 1;
+            PropertySet p;
+            p.setInt("i", 0, a);
+            int b = 0.0;
+            p.getInt("i", 0, &b);
+            assert(b);
+            assert(b == a);
+        }
+        {
+            int v0 = 0;
+            int v1 = 1;
+            void* a[] = { &v0, &v1 };
+            PropertySet p;
+            p.setPointerN("p", 2, a);
+            void* b[2] = { nullptr, nullptr };
+            p.getPointerN("p", 2, b);
+            assert(b);
+            assert(b[0] == a[0]);
+            assert(b[1] == a[1]);
+        }
+        {
+            std::string v[2] = { "v0", "v1" };
+            const char* a[] = { v[0].c_str(), v[1].c_str() };
+            PropertySet p;
+            p.setStringN("s", 2, a);
+            char* b[2] = { nullptr, nullptr };
+            p.getStringN("s", 2, b);
+            assert(b);
+            assert(b[0] == v[0]);
+            assert(b[1] == v[1]);
+        }
+        {
+            double a[2] = { 1.0, 2.0 };
+            PropertySet p;
+            p.setDoubleN("d", 2, a);
+            double b[2] = { 0.0, 0.0 };
+            p.getDoubleN("d", 2, b);
+            assert(b[0] == a[0]);
+            assert(b[1] == a[1]);
+        }
+        {
+            int a[2] = { 1, 2 };
+            PropertySet p;
+            p.setIntN("i", 2, a);
+            int b[2] = { 0, 0 };
+            p.getIntN("i", 2, b);
+            assert(b[0] == a[0]);
+            assert(b[1] == a[1]);
+        }
+        {
+            PropertySet p;
+            int dim = 0;
+            p.getDimension("i", &dim);
+            assert(0 == dim);
+            p.setInt("i", 0, 1);
+            dim = 0;
+            p.getDimension("i", &dim);
+            assert(1 == dim);
+            p.setInt("i", 1, 2);
+            dim = 0;
+            p.getDimension("i", &dim);
+            assert(2 == dim);
+        }
+        {
+            PropertySet p;
+            OfxStatus status = p.reset("i");
+            assert(status != kOfxStatOK);
+            p.setInt("i", 0, 1);
+            status = p.reset("i");
+            assert(kOfxStatOK == status);
+        }
+    }
+}
diff --git a/tests/PropertySetTest.h b/tests/PropertySetTest.h
new file mode 100644
index 0000000..8d29bed
--- /dev/null
+++ b/tests/PropertySetTest.h
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (c) 2024 Darby Johnston
+// All rights reserved.
+
+#pragma once
+
+namespace toucan
+{
+    void propertySetTest();
+}
diff --git a/tests/ReadOpTest.cpp b/tests/ReadOpTest.cpp
index 697bd16..f86123f 100644
--- a/tests/ReadOpTest.cpp
+++ b/tests/ReadOpTest.cpp
@@ -10,11 +10,13 @@
 
 namespace toucan
 {
-    void readOpTest(const std::filesystem::path& path)
+    void readOpTest(
+        const std::filesystem::path& path,
+        const std::shared_ptr<Host>& host)
     {
         std::cout << "readOpTest" << std::endl;
         auto read = std::make_shared<ReadOp>(path / "Letter_A.png");
-        auto buf = read->exec(OTIO_NS::RationalTime());
+        auto buf = read->exec(OTIO_NS::RationalTime(), host);
         const auto& spec = buf.spec();
         assert(spec.width > 0);
     }
diff --git a/tests/ReadOpTest.h b/tests/ReadOpTest.h
index 1179e13..9b4ea26 100644
--- a/tests/ReadOpTest.h
+++ b/tests/ReadOpTest.h
@@ -4,9 +4,11 @@
 
 #pragma once
 
-#include <filesystem>
+#include <toucan/Host.h>
 
 namespace toucan
 {
-    void readOpTest(const std::filesystem::path&);
+    void readOpTest(
+        const std::filesystem::path&,
+        const std::shared_ptr<Host>&);
 }
diff --git a/tests/TimelineTraverseTest.cpp b/tests/TimelineTraverseTest.cpp
index 5b13180..dbd8749 100644
--- a/tests/TimelineTraverseTest.cpp
+++ b/tests/TimelineTraverseTest.cpp
@@ -11,7 +11,9 @@
 
 namespace toucan
 {
-    void timelineTraverseTest(const std::filesystem::path& path)
+    void timelineTraverseTest(
+        const std::filesystem::path& path,
+        const std::shared_ptr<Host>& host)
     {
         std::cout << "timelineTraverseTest" << std::endl;
         const std::vector<std::string> otioFiles =
@@ -57,7 +59,7 @@ namespace toucan
                 if (auto op = traverse->exec(time))
                 {
                     // Execute the image operation graph.
-                    const auto buf = op->exec(time);
+                    const auto buf = op->exec(time, host);
 
                     // Save the image.
                     std::stringstream ss;
diff --git a/tests/TimelineTraverseTest.h b/tests/TimelineTraverseTest.h
index a3149ba..37806f5 100644
--- a/tests/TimelineTraverseTest.h
+++ b/tests/TimelineTraverseTest.h
@@ -4,9 +4,11 @@
 
 #pragma once
 
-#include <filesystem>
+#include <toucan/Host.h>
 
 namespace toucan
 {
-    void timelineTraverseTest(const std::filesystem::path&);
+    void timelineTraverseTest(
+        const std::filesystem::path&,
+        const std::shared_ptr<Host>&);
 }
diff --git a/tests/main.cpp b/tests/main.cpp
index 8d5fe0c..9aae40a 100644
--- a/tests/main.cpp
+++ b/tests/main.cpp
@@ -3,11 +3,13 @@
 // All rights reserved.
 
 #include "CompOpTest.h"
+#include "PropertySetTest.h"
 #include "ReadOpTest.h"
 #include "TimelineTraverseTest.h"
 #include "UtilTest.h"
 
 #include <toucan/Init.h>
+#include <toucan/Host.h>
 
 #include <iostream>
 
@@ -20,11 +22,16 @@ int main(int argc, char** argv)
         std::cout << "Usage: toucan-test (path to test data)" << std::endl;
         return 1;
     }
+    const std::filesystem::path parentPath = std::filesystem::path(argv[0]).parent_path();
     const std::filesystem::path path(argv[1]);
     init();
-    compOpTest(path);
-    readOpTest(path);
-    timelineTraverseTest(path);
+    auto host = std::make_shared<Host>(std::vector<std::filesystem::path>{
+        parentPath,
+        parentPath / ".." / ".."});
+    compOpTest(path, host);
+    propertySetTest();
+    readOpTest(path, host);
+    timelineTraverseTest(path, host);
     utilTest(path);
     return 0;
 }