Surface Responses output_text logprobs on the text content

provider/openaiprovider/responses.go

@@ -1120,6 +1120,9 @@ func responsesProcessResponse(resp *responses.Response, seqNum int64, yield func
 				case responses.ResponseOutputText:
 					textContent := &message.TextContent{Text: c.Text}
 					populateAnnotations(c.Annotations, textContent)
+					if len(c.Logprobs) > 0 {
+						textContent.AdditionalProperties = map[string]any{"Logprobs": c.Logprobs}
+					}
 					currentUpdate.Contents = append(currentUpdate.Contents, textContent)
 				case responses.ResponseOutputRefusal:
 					currentUpdate.Contents = append(currentUpdate.Contents, &message.ErrorContent{
@@ -1582,24 +1585,27 @@ func responsesProcessStreamingUpdate(update responses.ResponseStreamEventUnion,
 			u.Role = state.role
 			// For messages, only emit content if there are annotations that weren't in delta events
 			// Delta events handle the text itself, but annotations only appear in done events
-			hasAnnotations := false
+			hasMetadata := false
 			for _, c := range item.Content {
-				if c, ok := c.AsAny().(responses.ResponseOutputText); ok && len(c.Annotations) > 0 {
-					hasAnnotations = true
+				if c, ok := c.AsAny().(responses.ResponseOutputText); ok && (len(c.Annotations) > 0 || len(c.Logprobs) > 0) {
+					hasMetadata = true
 					break
 				}
 			}
 
-			if hasAnnotations {
+			if hasMetadata {
 				annotatedContent := &message.TextContent{}
 				for _, c := range item.Content {
 					if outputText, ok := c.AsAny().(responses.ResponseOutputText); ok {
 						populateAnnotations(outputText.Annotations, annotatedContent)
+						if len(outputText.Logprobs) > 0 {
+							annotatedContent.AdditionalProperties = map[string]any{"Logprobs": outputText.Logprobs}
+						}
 					}
 				}
 				u.Contents = []message.Content{annotatedContent}
 			}
-			// If no annotations, don't emit content (delta events already did)
+			// If no annotations or logprobs, don't emit content (delta events already did)
 
 		case responses.ResponseFunctionToolCall:
 			state.anyFunctions = true

provider/openaiprovider/responses_test.go

@@ -153,6 +153,43 @@ func TestResponsesRequestIncludesAgentFrameworkUserAgent(t *testing.T) {
 	}
 }
 
+// output_text logprobs must be surfaced on the TextContent's
+// AdditionalProperties, matching the Python client which stores them there.
+func TestResponsesOutputTextLogprobsSurfaced_NonStreaming(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = io.WriteString(w, `{
+			"id":"resp_lp",
+			"object":"response",
+			"created_at":1741891428,
+			"status":"completed",
+			"error":null,
+			"incomplete_details":null,
+			"model":"gpt-4o-mini",
+			"output":[{"type":"message","id":"msg_lp","status":"completed","role":"assistant","content":[{"type":"output_text","text":"hello","annotations":[],"logprobs":[{"token":"hello","logprob":-0.05,"bytes":[104,101,108,108,111],"top_logprobs":[]}]}]}]
+		}`)
+	}))
+	defer server.Close()
+
+	resp, err := newTestResponsesClient(server, "gpt-4o-mini").RunText(t.Context(), "hi").Collect()
+	if err != nil {
+		t.Fatalf("error = %v", err)
+	}
+
+	var text *message.TextContent
+	for content := range resp.Contents() {
+		if tc, ok := content.(*message.TextContent); ok {
+			text = tc
+		}
+	}
+	if text == nil {
+		t.Fatalf("no TextContent in response")
+	}
+	if _, ok := text.AdditionalProperties["Logprobs"]; !ok {
+		t.Errorf("Logprobs missing from TextContent AdditionalProperties: %#v", text.AdditionalProperties)
+	}
+}
+
 func TestNewAgentCurrentlyUsesResponsesAPI(t *testing.T) {
 	const input = `
 			{