diff --git a/type_definition.go b/type_definition.go
new file mode 100644
index 0000000..50538f6
--- /dev/null
+++ b/type_definition.go
@@ -0,0 +1,35 @@
+package protocol
+
+type TypeDefinitionResult struct {
+	Vertex
+}
+
+func NewTypeDefinitionResult(id uint64) TypeDefinitionResult {
+	return TypeDefinitionResult{Vertex{
+		Element: Element{
+			ID:   id,
+			Type: ElementVertex,
+		},
+		Label: VertexTypeDefinitionResult,
+	}}
+}
+
+type TextDocumentTypeDefinition struct {
+	Edge
+	OutV uint64 `json:"outV"`
+	InV  uint64 `json:"inV"`
+}
+
+func NewTextDocumentTypeDefinition(id uint64, outV, inV uint64) TextDocumentTypeDefinition {
+	return TextDocumentTypeDefinition{
+		Edge: Edge{
+			Element: Element{
+				ID:   id,
+				Type: ElementEdge,
+			},
+			Label: EdgeTextDocumentTypeDefinition,
+		},
+		OutV: outV,
+		InV:  inV,
+	}
+}
diff --git a/writer/emitter.go b/writer/emitter.go
index a4cd505..a1c7b0e 100644
--- a/writer/emitter.go
+++ b/writer/emitter.go
@@ -68,12 +68,24 @@ func (e *Emitter) EmitDefinitionResult() uint64 {
 	return id
 }
 
+func (e *Emitter) EmitTypeDefinitionResult() uint64 {
+	id := e.nextID()
+	e.writer.Write(protocol.NewTypeDefinitionResult(id))
+	return id
+}
+
 func (e *Emitter) EmitTextDocumentDefinition(outV, inV uint64) uint64 {
 	id := e.nextID()
 	e.writer.Write(protocol.NewTextDocumentDefinition(id, outV, inV))
 	return id
 }
 
+func (e *Emitter) EmitTextDocumentTypeDefinition(outV, inV uint64) uint64 {
+	id := e.nextID()
+	e.writer.Write(protocol.NewTextDocumentTypeDefinition(id, outV, inV))
+	return id
+}
+
 func (e *Emitter) EmitReferenceResult() uint64 {
 	id := e.nextID()
 	e.writer.Write(protocol.NewReferenceResult(id))