diff --git a/go/ai/document.go b/go/ai/document.go
index 33fec9811..eb40f3717 100644
--- a/go/ai/document.go
+++ b/go/ai/document.go
@@ -42,20 +42,26 @@ type partKind int8
 
 const (
 	partText partKind = iota
-	partBlob
+	partMedia
+	partData
 	partToolRequest
 	partToolResponse
 )
 
-// NewTextPart returns a Part containing raw string data.
+// NewTextPart returns a Part containing text.
 func NewTextPart(text string) *Part {
 	return &Part{kind: partText, text: text}
 }
 
-// NewBlobPart returns a Part containing structured data described
+// NewMediaPart returns a Part containing structured data described
 // by the given mimeType.
-func NewBlobPart(mimeType, contents string) *Part {
-	return &Part{kind: partBlob, contentType: mimeType, text: contents}
+func NewMediaPart(mimeType, contents string) *Part {
+	return &Part{kind: partMedia, contentType: mimeType, text: contents}
+}
+
+// NewDataPart returns a Part containing raw string data.
+func NewDataPart(contents string) *Part {
+	return &Part{kind: partData, text: contents}
 }
 
 // NewToolRequestPart returns a Part containing a request from
@@ -76,9 +82,14 @@ func (p *Part) IsText() bool {
 	return p.kind == partText
 }
 
-// IsBlob reports whether the [Part] contains blob (non-plain-text) data.
-func (p *Part) IsBlob() bool {
-	return p.kind == partBlob
+// IsMedia reports whether the [Part] contains structured media data.
+func (p *Part) IsMedia() bool {
+	return p.kind == partMedia
+}
+
+// IsData reports whether the [Part] contains unstructured data.
+func (p *Part) IsData() bool {
+	return p.kind == partData
 }
 
 // IsToolRequest reports whether the [Part] contains a request to run a tool.
@@ -128,7 +139,7 @@ func (p *Part) MarshalJSON() ([]byte, error) {
 			Text: p.text,
 		}
 		return json.Marshal(v)
-	case partBlob:
+	case partMedia:
 		v := mediaPart{
 			Media: &mediaPartMedia{
 				ContentType: p.contentType,
@@ -136,6 +147,11 @@ func (p *Part) MarshalJSON() ([]byte, error) {
 			},
 		}
 		return json.Marshal(v)
+	case partData:
+		v := dataPart{
+			Data: p.text,
+		}
+		return json.Marshal(v)
 	case partToolRequest:
 		// TODO: make sure these types marshal/unmarshal nicely
 		// between Go and javascript. At the very least the
@@ -166,6 +182,7 @@ func (p *Part) UnmarshalJSON(b []byte) error {
 	var s struct {
 		Text     string          `json:"text,omitempty"`
 		Media    *mediaPartMedia `json:"media,omitempty"`
+		Data     string          `json:"data,omitempty"`
 		ToolReq  *ToolRequest    `json:"toolreq,omitempty"`
 		ToolResp *ToolResponse   `json:"toolresp,omitempty"`
 	}
@@ -176,7 +193,7 @@ func (p *Part) UnmarshalJSON(b []byte) error {
 
 	switch {
 	case s.Media != nil:
-		p.kind = partBlob
+		p.kind = partMedia
 		p.text = s.Media.Url
 		p.contentType = s.Media.ContentType
 	case s.ToolReq != nil:
@@ -189,6 +206,11 @@ func (p *Part) UnmarshalJSON(b []byte) error {
 		p.kind = partText
 		p.text = s.Text
 		p.contentType = ""
+		if s.Data != "" {
+			// Note: if part is completely empty, we use text by default.
+			p.kind = partData
+			p.text = s.Data
+		}
 	}
 	return nil
 }
diff --git a/go/ai/document_test.go b/go/ai/document_test.go
index 0ca412b3a..bc30eb7f4 100644
--- a/go/ai/document_test.go
+++ b/go/ai/document_test.go
@@ -46,10 +46,14 @@ func TestDocumentJSON(t *testing.T) {
 				text: "hi",
 			},
 			&Part{
-				kind:        partBlob,
+				kind:        partMedia,
 				contentType: "text/plain",
 				text:        "data:,bye",
 			},
+			&Part{
+				kind: partData,
+				text: "somedata\x00string",
+			},
 			&Part{
 				kind: partToolRequest,
 				toolRequest: &ToolRequest{
@@ -85,8 +89,10 @@ func TestDocumentJSON(t *testing.T) {
 		switch a.kind {
 		case partText:
 			return a.text == b.text
-		case partBlob:
+		case partMedia:
 			return a.contentType == b.contentType && a.text == b.text
+		case partData:
+			return a.text == b.text
 		case partToolRequest:
 			return reflect.DeepEqual(a.toolRequest, b.toolRequest)
 		case partToolResponse:
diff --git a/go/ai/gen.go b/go/ai/gen.go
index 531c6fcbc..bf440600f 100644
--- a/go/ai/gen.go
+++ b/go/ai/gen.go
@@ -53,7 +53,7 @@ const (
 	FinishReasonUnknown FinishReason = "unknown"
 )
 
-type DataPart struct {
+type dataPart struct {
 	Data     any            `json:"data,omitempty"`
 	Metadata map[string]any `json:"metadata,omitempty"`
 }
diff --git a/go/core/schemas.config b/go/core/schemas.config
index c7c402875..76aa30e37 100644
--- a/go/core/schemas.config
+++ b/go/core/schemas.config
@@ -127,7 +127,6 @@ Candidate						pkg ai
 CandidateError					pkg ai
 CandidateErrorCode				pkg ai
 CandidateFinishReason			pkg ai
-DataPart						pkg ai
 DocumentData					pkg ai
 GenerateResponse				pkg ai
 GenerateResponseChunk			pkg ai
@@ -159,6 +158,8 @@ MediaPart.toolRequest			omit
 MediaPart.toolResponse			omit
 MediaPartMedia					pkg ai
 MediaPartMedia					name mediaPartMedia
+DataPart						pkg ai
+DataPart						name dataPart
 ModelInfo						pkg ai
 ModelInfoSupports				pkg ai
 ModelInfoSupports.output  		type OutputFormat
diff --git a/go/plugins/dotprompt/render.go b/go/plugins/dotprompt/render.go
index 20fd9edeb..82bda0a89 100644
--- a/go/plugins/dotprompt/render.go
+++ b/go/plugins/dotprompt/render.go
@@ -184,7 +184,7 @@ func (p *Prompt) toParts(str string) []*ai.Part {
 
 		media := str[m[0]+len(mediaPrefix) : m[1]-len(mediaSuffix)]
 		url, contentType, _ := strings.Cut(media, " ")
-		ret = append(ret, ai.NewBlobPart(contentType, url))
+		ret = append(ret, ai.NewMediaPart(contentType, url))
 
 		i = m[1]
 	}
diff --git a/go/plugins/dotprompt/render_test.go b/go/plugins/dotprompt/render_test.go
index 27b98d8d9..8ffe1022e 100644
--- a/go/plugins/dotprompt/render_test.go
+++ b/go/plugins/dotprompt/render_test.go
@@ -115,7 +115,7 @@ func TestRenderMessages(t *testing.T) {
 				{
 					Role: ai.RoleUser,
 					Content: []*ai.Part{
-						ai.NewBlobPart("", "https://some.image.url/image.jpg"),
+						ai.NewMediaPart("", "https://some.image.url/image.jpg"),
 						ai.NewTextPart(" Describe the image above."),
 					},
 				},
@@ -137,11 +137,11 @@ func TestRenderMessages(t *testing.T) {
 					Role: ai.RoleUser,
 					Content: []*ai.Part{
 						ai.NewTextPart("Look at these images: "),
-						ai.NewBlobPart("", "http://1.png"),
-						ai.NewBlobPart("", "https://2.png"),
-						ai.NewBlobPart("", "data:image/jpeg;base64,abc123"),
+						ai.NewMediaPart("", "http://1.png"),
+						ai.NewMediaPart("", "https://2.png"),
+						ai.NewMediaPart("", "data:image/jpeg;base64,abc123"),
 						ai.NewTextPart("  Do you like them? Here is another: "),
-						ai.NewBlobPart("", "http://anotherImage.png"),
+						ai.NewMediaPart("", "http://anotherImage.png"),
 					},
 				},
 			},
diff --git a/go/plugins/googleai/googleai.go b/go/plugins/googleai/googleai.go
index f2dedc32f..17eea79c1 100644
--- a/go/plugins/googleai/googleai.go
+++ b/go/plugins/googleai/googleai.go
@@ -164,7 +164,7 @@ func translateCandidate(cand *genai.Candidate) *ai.Candidate {
 		case genai.Text:
 			p = ai.NewTextPart(string(part))
 		case genai.Blob:
-			p = ai.NewBlobPart(part.MIMEType, string(part.Data))
+			p = ai.NewMediaPart(part.MIMEType, string(part.Data))
 		case genai.FunctionCall:
 			p = ai.NewToolRequestPart(&ai.ToolRequest{
 				Name:  part.Name,
@@ -236,8 +236,10 @@ func convertPart(p *ai.Part) genai.Part {
 	switch {
 	case p.IsText():
 		return genai.Text(p.Text())
-	case p.IsBlob():
+	case p.IsMedia():
 		return genai.Blob{MIMEType: p.ContentType(), Data: []byte(p.Text())}
+	case p.IsData():
+		panic("googleai does not support Data parts")
 	case p.IsToolResponse():
 		toolResp := p.ToolResponse()
 		return genai.FunctionResponse{
diff --git a/go/plugins/vertexai/vertexai.go b/go/plugins/vertexai/vertexai.go
index ff00c0555..f9e0c1c67 100644
--- a/go/plugins/vertexai/vertexai.go
+++ b/go/plugins/vertexai/vertexai.go
@@ -137,7 +137,7 @@ func translateCandidate(cand *genai.Candidate) *ai.Candidate {
 		case genai.Text:
 			p = ai.NewTextPart(string(part))
 		case genai.Blob:
-			p = ai.NewBlobPart(part.MIMEType, string(part.Data))
+			p = ai.NewMediaPart(part.MIMEType, string(part.Data))
 		case genai.FunctionCall:
 			p = ai.NewToolRequestPart(&ai.ToolRequest{
 				Name:  part.Name,
@@ -204,8 +204,10 @@ func convertPart(p *ai.Part) genai.Part {
 	switch {
 	case p.IsText():
 		return genai.Text(p.Text())
-	case p.IsBlob():
+	case p.IsMedia():
 		return genai.Blob{MIMEType: p.ContentType(), Data: []byte(p.Text())}
+	case p.IsData():
+		panic("vertexai does not support Data parts")
 	case p.IsToolResponse():
 		toolResp := p.ToolResponse()
 		return genai.FunctionResponse{