diff --git a/curves.json b/curves.json
new file mode 100644
index 0000000..7aab9df
--- /dev/null
+++ b/curves.json
@@ -0,0 +1,23 @@
+{
+	"dof:sharp-distance" : [
+		{
+			"type" : "smooth" ,
+			"values" : [ 35 , 100 , 35 ] ,
+			"durations" : [ 300 , 300 ]
+		}
+	] ,
+	"dof:sharp-range" : [
+		{
+			"type" : "smooth" ,
+			"values" : [ 20 , 2 ] ,
+			"durations" : [ 900 ]
+		}
+	] ,
+	"dof:falloff" : [
+		{
+			"type" : "linear" ,
+			"values" : [ 2 , 2 ] ,
+			"durations" : [ 1 ]
+		}
+	]
+}
diff --git a/demo.cc b/demo.cc
index 880d9bb..1ab049d 100644
--- a/demo.cc
+++ b/demo.cc
@@ -24,40 +24,12 @@ bool T_Demo::initialise( )
 			combine->output( ) );
 
 	Globals::Sync( ).clearInputs( );
+	// XXX should come from program
 	Globals::Sync( ).addInput( "dof:sharp-distance" , 15 );
 	Globals::Sync( ).addInput( "dof:sharp-range" , 5 );
 	Globals::Sync( ).addInput( "dof:falloff" , 10 );
 	Globals::Sync( ).addInput( "dof:max-blur" , 16 );
 	Globals::Sync( ).addInput( "dof:samples" , 16 );
-
-	// XXX test curve
-	{
-		T_SyncCurve curve;
-		curve.name = "dof:sharp-distance";
-		{
-			T_SyncSegment seg;
-			seg.nPoints = 4;
-			seg.type = T_SyncSegment::SMOOTH;
-			seg.durations.push_back( 300 );
-			seg.durations.push_back( 300 );
-			seg.durations.push_back( 300 );
-			seg.values.push_back( 15 );
-			seg.values.push_back( 30 );
-			seg.values.push_back( 15 );
-			seg.values.push_back( 15 );
-			curve.segments.emplace_back( std::move( seg ) );
-		}
-		{
-			T_SyncSegment seg;
-			seg.nPoints = 2;
-			seg.type = T_SyncSegment::LINEAR;
-			seg.durations.push_back( 600 );
-			seg.values.push_back( 100 );
-			seg.values.push_back( 20 );
-			curve.segments.emplace_back( std::move( seg ) );
-		}
-		Globals::Sync( ).setCurve( std::move( curve ) );
-	}
 	Globals::Sync( ).updateCurveCaches( );
 
 	return true;
diff --git a/filewatcher.hh b/filewatcher.hh
index 51b4219..11d7861 100644
--- a/filewatcher.hh
+++ b/filewatcher.hh
@@ -52,4 +52,4 @@ struct T_WatchedFiles
 	bool triggered;
 	std::vector< int > identifiers;
 };
-
+using P_WatchedFiles = std::unique_ptr< T_WatchedFiles >;
diff --git a/main.cc b/main.cc
index 20a3a53..21a1608 100644
--- a/main.cc
+++ b/main.cc
@@ -71,6 +71,7 @@ void T_Main::mainLoop( )
 
 		Globals::Watcher( ).check( );
 		Globals::Shaders( ).update( );
+		Globals::Sync( ).checkCurveFile( );
 
 		glFinish( );
 		p.startFrame( );
diff --git a/sync.cc b/sync.cc
index a27cec3..e220d2b 100644
--- a/sync.cc
+++ b/sync.cc
@@ -1,5 +1,18 @@
 #include "externals.hh"
 #include "sync.hh"
+#include "globals.hh"
+
+namespace {
+
+const std::map< std::string , T_SyncSegment::E_SegmentType > SegmentTypes_( ([] {
+	std::map< std::string , T_SyncSegment::E_SegmentType > t;
+	t.emplace( "linear" , T_SyncSegment::LINEAR );
+	t.emplace( "ramp" , T_SyncSegment::RAMP );
+	t.emplace( "smooth" , T_SyncSegment::SMOOTH );
+	return t;
+})());
+
+}
 
 
 /*= T_SyncTime ===============================================================*/
@@ -228,6 +241,23 @@ void T_SyncManager::setTime(
 
 /*----------------------------------------------------------------------------*/
 
+void T_SyncManager::checkCurveFile( )
+{
+	if ( watcher_ ) {
+		return;
+	}
+
+	printf( "CURVE INIT\n" );
+	bool missing;
+	if ( loadCurves_( missing ) || !missing ) {
+		watcher_ = std::make_unique< T_WatchedFiles >(
+				Globals::Watcher( ) ,
+				[this] { curvesChanged_( ); } );
+		watcher_->watch( "curves.json" );
+	}
+	printf( "INIT MISSING IS %c\n" , missing ? 'Y' : 'N' );
+}
+
 void T_SyncManager::clearCurves( )
 {
 	curves_.clear( );
@@ -241,6 +271,174 @@ void T_SyncManager::setCurve(
 	updateCurveCaches( );
 }
 
+void T_SyncManager::curvesChanged_( )
+{
+	bool missing;
+	if ( !loadCurves_( missing ) && missing ) {
+		watcher_.reset( );
+	} else {
+		// XXX temp bullshit to work around the deletion problem
+		watcher_->clear( );
+		watcher_->watch( "curves.json" );
+	}
+}
+
+bool T_SyncManager::loadCurves_(
+		__wr__ bool& missing )
+{
+	using T_STI_ = std::istream_iterator< char >;
+	std::ifstream file( "curves.json" );
+	picojson::value root;
+	try {
+		missing = !file.is_open( );
+		if ( missing ) {
+			return false;
+		}
+
+		std::string errors;
+		picojson::parse( root , T_STI_( file ) , T_STI_( ) , &errors );
+		if ( !errors.empty( ) ) {
+			printf( "Failed to parse 'curves.json':\n%s\n" , errors.c_str( ) );
+			return false;
+		}
+	} catch ( std::ios_base::failure const& e ) {
+		printf( "I/O error while reading 'curves.json'\n%s\n" , e.what( ) );
+		missing = false;
+		return false;
+	}
+
+	T_SyncCurves nCurves;
+	if ( !loadCurvesData_( nCurves , root ) ) {
+		return false;
+	}
+	curves_ = std::move( nCurves );
+	updateCurveCaches( );
+	return true;
+}
+
+bool T_SyncManager::loadCurvesData_(
+		__wr__ T_SyncCurves& curves ,
+		__rd__ picojson::value const& root )
+{
+	if ( !root.is< T_JSONObject >( ) ) {
+		printf( "Curves data: root is not a JSON object\n" );
+		return false;
+	}
+
+	auto const& r( root.get< T_JSONObject >( ) );
+	bool ok( true );
+	for ( auto const& item : r ) {
+		if ( curves.indexOf( item.first ) != -1 ) {
+			printf( "Curves data: duplicate curve '%s'\n" ,
+					item.first.c_str( ) );
+			ok = false;
+			continue;
+		}
+		if ( !item.second.is< T_JSONArray >( ) ) {
+			printf( "Curves data: entry for curve '%s' is not an array\n" ,
+					item.first.c_str( ) );
+			ok = false;
+			continue;
+		}
+
+		T_SyncCurve nsc;
+		nsc.name = item.first;
+
+		bool segsOk( true );
+		for ( auto const& v : item.second.get< T_JSONArray >( ) ) {
+			if ( !v.is< T_JSONObject >( ) ) {
+				printf( "Curves data: curve '%s': invalid segment\n" ,
+						item.first.c_str( ) );
+				segsOk = false;
+				continue;
+			}
+
+			T_SyncSegment segment;
+			try {
+				if ( !loadSegmentData_( segment , nsc.name ,
+						v.get< T_JSONObject >( ) ) ) {
+					segsOk = false;
+					continue;
+				}
+			} catch ( X_JsonGetFailed const& ) {
+				printf( "Curves data: curve '%s': could not parse segment data\n" ,
+						item.first.c_str( ) );
+				segsOk = false;
+				continue;
+			}
+			nsc.segments.emplace_back( std::move( segment ) );
+		}
+
+		ok = ok && segsOk;
+		if ( nsc.segments.empty( ) && segsOk ) {
+			printf( "Curves data: curve '%s': no segments\n" ,
+					item.first.c_str( ) );
+			ok = false;
+		}
+		curves.setCurve( std::move( nsc ) );
+	}
+
+	return ok;
+}
+
+bool T_SyncManager::loadSegmentData_(
+		__wr__ T_SyncSegment& segment ,
+		__rd__ std::string const& curve ,
+		__rd__ T_JSONObject const& sd )
+{
+	auto const& sType( jsonGet< std::string >( sd , "type" ) );
+
+	const auto p( SegmentTypes_.find( sType ) );
+	if ( p == SegmentTypes_.end( ) ) {
+		printf( "Curves data: curve '%s': invalid segment type '%s'\n" ,
+				curve.c_str( ) , sType.c_str( ) );
+		return false;
+	}
+	segment.type = p->second;
+
+	auto const& vList( jsonGet< T_JSONArray >( sd , "values" ) );
+	auto const& dList( jsonGet< T_JSONArray >( sd , "durations" ) );
+
+	if ( vList.size( ) < 2 ) {
+		printf( "Curves data: curve '%s': segment doesn't have enough values\n" ,
+				curve.c_str( ) );
+		return false;
+	}
+	if ( vList.size( ) != dList.size( ) + 1 ) {
+		printf( "Curves data: curve '%s': segment values / durations count mismatch\n" ,
+				curve.c_str( ) );
+		return false;
+	}
+
+	for ( auto const& vv : vList ) {
+		if ( !vv.is< double >( ) ) {
+			printf( "Curves data: curve '%s': non-numeric entry in segment values\n" ,
+					curve.c_str( ) );
+			return false;
+		}
+		segment.values.push_back( float( vv.get< double >( ) ) );
+	}
+
+	for ( auto const& dv : dList ) {
+		if ( !dv.is< double >( ) ) {
+			printf( "Curves data: curve '%s': non-numeric entry in segment durations\n" ,
+					curve.c_str( ) );
+			return false;
+		}
+
+		const double dvn( dv.get< double >( ) );
+		if ( fmod( dvn , 1.0 ) != 0.0 || dvn <= 0 ) {
+			printf( "Curves data: curve '%s': invalid segment duration %f\n" ,
+					curve.c_str( ) , dvn );
+			return false;
+		}
+		segment.durations.push_back( uint32_t( dvn ) );
+	}
+
+	segment.nPoints = segment.values.size( );
+	return true;
+}
+
 /*----------------------------------------------------------------------------*/
 
 void T_SyncManager::updateCurveCaches( )
diff --git a/sync.hh b/sync.hh
index 6e4c76b..92315e1 100644
--- a/sync.hh
+++ b/sync.hh
@@ -1,8 +1,6 @@
 #pragma once
-#ifndef REAL_BUILD
-# include "externals.hh"
-#endif
-
+#include "filewatcher.hh"
+#include "utilities.hh"
 
 // Duration and current playing time
 struct T_SyncTime
@@ -174,15 +172,30 @@ struct T_SyncManager
 	// ---------------------------------------------------------------------
 	// Curves
 
+	void checkCurveFile( );
 	void clearCurves( );
 	void setCurve( __rd__ T_SyncCurve curve );
 
-	// ---------------------------------------------------------------------
+    private:
+	void curvesChanged_( );
+	bool loadCurves_( __wr__ bool& missing );
+	bool loadCurvesData_(
+			__wr__ T_SyncCurves& curves ,
+			__rd__ picojson::value const& root );
+	bool loadSegmentData_(
+			__wr__ T_SyncSegment& segment ,
+			__rd__ std::string const& curve ,
+			__rd__ T_JSONObject const& sd );
 
+	// ---------------------------------------------------------------------
+	// Update
+
+    public:
 	void updateCurveCaches( );
 	void updateValues( );
 
     private:
+	P_WatchedFiles watcher_;
 	T_SyncTime time_;
 	T_SyncValues values_;
 	T_SyncCurves curves_;
diff --git a/utilities.cc b/utilities.cc
index 4cc285c..2ab17c4 100644
--- a/utilities.cc
+++ b/utilities.cc
@@ -44,25 +44,25 @@ void anglesToMatrix(
 /*= JSON =====================================================================*/
 
 template void jsonAdd< double >(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ double const& v );
-template void jsonAdd< picojson::value::object >(
-		__rw__ picojson::value::object& object ,
+template void jsonAdd< T_JSONObject >(
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
-		__rd__ picojson::value::object const& v );
-template void jsonAdd< picojson::value::array >(
-		__rw__ picojson::value::object& object ,
+		__rd__ T_JSONObject const& v );
+template void jsonAdd< T_JSONArray >(
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
-		__rd__ picojson::value::array const& v );
+		__rd__ T_JSONArray const& v );
 template void jsonAdd< std::string >(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ std::string const& v );
 
 template< >
 void jsonAdd< picojson::value >(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ picojson::value const& v )
 {
@@ -72,7 +72,7 @@ void jsonAdd< picojson::value >(
 
 template< >
 void jsonAdd< int >(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ int const& v )
 {
@@ -82,7 +82,7 @@ void jsonAdd< int >(
 
 template< >
 void jsonAdd< unsigned >(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ unsigned const& v )
 {
@@ -107,7 +107,7 @@ picojson::value jsonVector( float const* vector , const int nComponents )
 void jsonGetVectorOpt(
 		__wr__ float* vector ,
 		__rd__ const size_t size ,
-		__rd__ picojson::value::object const& object ,
+		__rd__ T_JSONObject const& object ,
 		__rd__ char const* key )
 {
 	using namespace picojson;
diff --git a/utilities.hh b/utilities.hh
index d646e25..0918e43 100644
--- a/utilities.hh
+++ b/utilities.hh
@@ -62,6 +62,9 @@ inline auto find(
 
 /*= JSON utilities ===========================================================*/
 
+using T_JSONObject = picojson::value::object;
+using T_JSONArray = picojson::value::array;
+
 // Convert a vector to a JSON array
 picojson::value jsonVector(
 		__rd__ float const* vector ,
@@ -77,7 +80,7 @@ inline picojson::value jsonVector(
 // Add an entry to a JSON object
 template< typename T >
 inline void jsonAdd(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ T const& v )
 {
@@ -86,35 +89,35 @@ inline void jsonAdd(
 }
 
 extern template void jsonAdd< double >(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ double const& v );
-extern template void jsonAdd< picojson::value::object >(
-		__rw__ picojson::value::object& object ,
+extern template void jsonAdd< T_JSONObject >(
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
-		__rd__ picojson::value::object const& v );
-extern template void jsonAdd< picojson::value::array >(
-		__rw__ picojson::value::object& object ,
+		__rd__ T_JSONObject const& v );
+extern template void jsonAdd< T_JSONArray >(
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
-		__rd__ picojson::value::array const& v );
+		__rd__ T_JSONArray const& v );
 extern template void jsonAdd< std::string >(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ std::string const& v );
 
 template< >
 void jsonAdd< picojson::value >(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ picojson::value const& v );
 template< >
 void jsonAdd< int >(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ int const& v );
 template< >
 void jsonAdd< unsigned >(
-		__rw__ picojson::value::object& object ,
+		__rw__ T_JSONObject& object ,
 		__rd__ std::string const& key ,
 		__rd__ unsigned const& v );
 
@@ -123,11 +126,30 @@ void jsonAdd< unsigned >(
 // JSON read type error
 class X_JsonGetFailed : public std::exception { };
 
+// Get a JSON object field; throws X_JsonGetFailed if the type is incorrect or
+// if the field is missing.
+template< typename T >
+inline T const& jsonGet(
+		__rd__ T_JSONObject const& object ,
+		__rd__ char const* const key )
+{
+	const std::string k( key );
+	if ( object.find( k ) == object.end( ) ) {
+		throw X_JsonGetFailed( );
+	}
+
+	picojson::value const& v( object.at( k ) );
+	if ( !v.is< T >( ) ) {
+		throw X_JsonGetFailed( );
+	}
+	return v.get< T >( );
+}
+
 // Get a pointer to a JSON object field, or nullptr if the field doesn't exist.
 // Throws X_JsonGetFailed if the type is incorrect.
 template< typename T >
 inline T const* jsonGetOpt(
-		__rd__ picojson::value::object const& object ,
+		__rd__ T_JSONObject const& object ,
 		__rd__ char const* const key )
 {
 	const std::string k( key );
@@ -147,7 +169,7 @@ inline T const* jsonGetOpt(
 template< typename T >
 inline bool jsonSetFromOpt(
 		__wr__ T& out ,
-		__rd__ picojson::value::object const& object ,
+		__rd__ T_JSONObject const& object ,
 		__rd__ char const* const key )
 {
 	T const* ptr( jsonGetOpt< T >( object , key ) );
@@ -161,7 +183,7 @@ inline bool jsonSetFromOpt(
 template< >
 inline bool jsonSetFromOpt< int >(
 		__wr__ int& out ,
-		__rd__ picojson::value::object const& object ,
+		__rd__ T_JSONObject const& object ,
 		__rd__ char const* const key )
 {
 	double const* ptr( jsonGetOpt< double >( object , key ) );
@@ -175,7 +197,7 @@ inline bool jsonSetFromOpt< int >(
 template< >
 inline bool jsonSetFromOpt< unsigned >(
 		__wr__ unsigned& out ,
-		__rd__ picojson::value::object const& object ,
+		__rd__ T_JSONObject const& object ,
 		__rd__ char const* const key )
 {
 	double const* ptr( jsonGetOpt< double >( object , key ) );
@@ -189,7 +211,7 @@ inline bool jsonSetFromOpt< unsigned >(
 template< >
 inline bool jsonSetFromOpt< float >(
 		__wr__ float& out ,
-		__rd__ picojson::value::object const& object ,
+		__rd__ T_JSONObject const& object ,
 		__rd__ char const* const key )
 {
 	double const* ptr( jsonGetOpt< double >( object , key ) );
@@ -203,13 +225,13 @@ inline bool jsonSetFromOpt< float >(
 void jsonGetVectorOpt(
 		__wr__ float* vector ,
 		__rd__ const size_t size ,
-		__rd__ picojson::value::object const& object ,
+		__rd__ T_JSONObject const& object ,
 		__rd__ char const* key );
 
 // Read a GLM vec3 from a JSON array of numbers
 inline void jsonGetVectorOpt(
 		__wr__ glm::vec3& vector ,
-		__rd__ picojson::value::object const& object ,
+		__rd__ T_JSONObject const& object ,
 		__rd__ char const* key )
 {
 	jsonGetVectorOpt( &vector.x , 3 , object , key );
@@ -219,12 +241,11 @@ inline void jsonGetVectorOpt(
 template< typename T >
 inline bool jsonLoadOpt(
 		__rw__ T& out ,
-		__rd__ picojson::value::object const& object ,
+		__rd__ T_JSONObject const& object ,
 		__rd__ char const* key )
 {
-	using T_Obj = picojson::value::object;
 	try {
-		auto const* sub( jsonGetOpt< T_Obj >( object , key ) );
+		auto const* sub( jsonGetOpt< T_JSONObject >( object , key ) );
 		if ( sub ) {
 			return out.load( *sub );
 		}