feat: Enhance DeepSeek API compatibility by updating SSE parsing, standardizing error responses, and improving API key management in the tester UI.

internal/sse/parser.go

@@ -59,6 +59,42 @@ func ParseSSEChunkForContent(chunk map[string]any, thinkingEnabled bool, current
 		}
 	}
 	newType := currentFragmentType
+	parts := make([]ContentPart, 0, 8)
+
+	// Newer DeepSeek responses may emit fragment APPEND directly on
+	// path "response/fragments" instead of wrapping it in path "response".
+	if path == "response/fragments" {
+		if op, _ := chunk["o"].(string); strings.EqualFold(op, "APPEND") {
+			if frags, ok := v.([]any); ok {
+				for _, frag := range frags {
+					fm, ok := frag.(map[string]any)
+					if !ok {
+						continue
+					}
+					t, _ := fm["type"].(string)
+					content, _ := fm["content"].(string)
+					t = strings.ToUpper(t)
+					switch t {
+					case "THINK", "THINKING":
+						newType = "thinking"
+						if content != "" {
+							parts = append(parts, ContentPart{Text: content, Type: "thinking"})
+						}
+					case "RESPONSE":
+						newType = "text"
+						if content != "" {
+							parts = append(parts, ContentPart{Text: content, Type: "text"})
+						}
+					default:
+						if content != "" {
+							parts = append(parts, ContentPart{Text: content, Type: "text"})
+						}
+					}
+				}
+			}
+		}
+	}
+
 	if path == "response" {
 		if arr, ok := v.([]any); ok {
 			for _, it := range arr {
@@ -99,7 +135,6 @@ func ParseSSEChunkForContent(chunk map[string]any, thinkingEnabled bool, current
 			partType = newType
 		}
 	}
-	parts := make([]ContentPart, 0, 8)
 	switch val := v.(type) {
 	case string:
 		if val == "FINISHED" && (path == "" || path == "status") {

internal/sse/parser_test.go

@@ -47,3 +47,43 @@ func TestIsCitation(t *testing.T) {
 		t.Fatal("expected citation false")
 	}
 }
+
+func TestParseSSEChunkForContentFragmentsAppendSwitchToResponse(t *testing.T) {
+	chunk := map[string]any{
+		"p": "response/fragments",
+		"o": "APPEND",
+		"v": []any{
+			map[string]any{
+				"type":    "RESPONSE",
+				"content": "你好",
+			},
+		},
+	}
+	parts, finished, nextType := ParseSSEChunkForContent(chunk, true, "thinking")
+	if finished {
+		t.Fatal("expected unfinished")
+	}
+	if nextType != "text" {
+		t.Fatalf("expected next type text, got %q", nextType)
+	}
+	if len(parts) != 1 || parts[0].Type != "text" || parts[0].Text != "你好" {
+		t.Fatalf("unexpected parts: %#v", parts)
+	}
+}
+
+func TestParseSSEChunkForContentAfterAppendUsesUpdatedType(t *testing.T) {
+	chunk := map[string]any{
+		"p": "response/fragments/-1/content",
+		"v": "！",
+	}
+	parts, finished, nextType := ParseSSEChunkForContent(chunk, true, "text")
+	if finished {
+		t.Fatal("expected unfinished")
+	}
+	if nextType != "text" {
+		t.Fatalf("expected next type text, got %q", nextType)
+	}
+	if len(parts) != 1 || parts[0].Type != "text" || parts[0].Text != "！" {
+		t.Fatalf("unexpected parts: %#v", parts)
+	}
+}