Merge pull request #1506 from masrurimz/fix-sse-model-mapping

fix(amp): rewrite response.model in Responses API SSE events

internal/api/modules/amp/response_rewriter.go

@@ -66,7 +66,7 @@ func (rw *ResponseRewriter) Flush() {
 }
 
 // modelFieldPaths lists all JSON paths where model name may appear
-var modelFieldPaths = []string{"model", "modelVersion", "response.modelVersion", "message.model"}
+var modelFieldPaths = []string{"message.model", "model", "modelVersion", "response.model", "response.modelVersion"}
 
 // rewriteModelInResponse replaces all occurrences of the mapped model with the original model in JSON
 // It also suppresses "thinking" blocks if "tool_use" is present to ensure Amp client compatibility

internal/api/modules/amp/response_rewriter_test.go

@@ -0,0 +1,110 @@
+package amp
+
+import (
+	"testing"
+)
+
+func TestRewriteModelInResponse_TopLevel(t *testing.T) {
+	rw := &ResponseRewriter{originalModel: "gpt-5.2-codex"}
+
+	input := []byte(`{"id":"resp_1","model":"gpt-5.3-codex","output":[]}`)
+	result := rw.rewriteModelInResponse(input)
+
+	expected := `{"id":"resp_1","model":"gpt-5.2-codex","output":[]}`
+	if string(result) != expected {
+		t.Errorf("expected %s, got %s", expected, string(result))
+	}
+}
+
+func TestRewriteModelInResponse_ResponseModel(t *testing.T) {
+	rw := &ResponseRewriter{originalModel: "gpt-5.2-codex"}
+
+	input := []byte(`{"type":"response.completed","response":{"id":"resp_1","model":"gpt-5.3-codex","status":"completed"}}`)
+	result := rw.rewriteModelInResponse(input)
+
+	expected := `{"type":"response.completed","response":{"id":"resp_1","model":"gpt-5.2-codex","status":"completed"}}`
+	if string(result) != expected {
+		t.Errorf("expected %s, got %s", expected, string(result))
+	}
+}
+
+func TestRewriteModelInResponse_ResponseCreated(t *testing.T) {
+	rw := &ResponseRewriter{originalModel: "gpt-5.2-codex"}
+
+	input := []byte(`{"type":"response.created","response":{"id":"resp_1","model":"gpt-5.3-codex","status":"in_progress"}}`)
+	result := rw.rewriteModelInResponse(input)
+
+	expected := `{"type":"response.created","response":{"id":"resp_1","model":"gpt-5.2-codex","status":"in_progress"}}`
+	if string(result) != expected {
+		t.Errorf("expected %s, got %s", expected, string(result))
+	}
+}
+
+func TestRewriteModelInResponse_NoModelField(t *testing.T) {
+	rw := &ResponseRewriter{originalModel: "gpt-5.2-codex"}
+
+	input := []byte(`{"type":"response.output_item.added","item":{"id":"item_1","type":"message"}}`)
+	result := rw.rewriteModelInResponse(input)
+
+	if string(result) != string(input) {
+		t.Errorf("expected no modification, got %s", string(result))
+	}
+}
+
+func TestRewriteModelInResponse_EmptyOriginalModel(t *testing.T) {
+	rw := &ResponseRewriter{originalModel: ""}
+
+	input := []byte(`{"model":"gpt-5.3-codex"}`)
+	result := rw.rewriteModelInResponse(input)
+
+	if string(result) != string(input) {
+		t.Errorf("expected no modification when originalModel is empty, got %s", string(result))
+	}
+}
+
+func TestRewriteStreamChunk_SSEWithResponseModel(t *testing.T) {
+	rw := &ResponseRewriter{originalModel: "gpt-5.2-codex"}
+
+	chunk := []byte("data: {\"type\":\"response.completed\",\"response\":{\"id\":\"resp_1\",\"model\":\"gpt-5.3-codex\",\"status\":\"completed\"}}\n\n")
+	result := rw.rewriteStreamChunk(chunk)
+
+	expected := "data: {\"type\":\"response.completed\",\"response\":{\"id\":\"resp_1\",\"model\":\"gpt-5.2-codex\",\"status\":\"completed\"}}\n\n"
+	if string(result) != expected {
+		t.Errorf("expected %s, got %s", expected, string(result))
+	}
+}
+
+func TestRewriteStreamChunk_MultipleEvents(t *testing.T) {
+	rw := &ResponseRewriter{originalModel: "gpt-5.2-codex"}
+
+	chunk := []byte("data: {\"type\":\"response.created\",\"response\":{\"model\":\"gpt-5.3-codex\"}}\n\ndata: {\"type\":\"response.output_item.added\",\"item\":{\"id\":\"item_1\"}}\n\n")
+	result := rw.rewriteStreamChunk(chunk)
+
+	if string(result) == string(chunk) {
+		t.Error("expected response.model to be rewritten in SSE stream")
+	}
+	if !contains(result, []byte(`"model":"gpt-5.2-codex"`)) {
+		t.Errorf("expected rewritten model in output, got %s", string(result))
+	}
+}
+
+func TestRewriteStreamChunk_MessageModel(t *testing.T) {
+	rw := &ResponseRewriter{originalModel: "claude-opus-4.5"}
+
+	chunk := []byte("data: {\"message\":{\"model\":\"claude-sonnet-4\",\"role\":\"assistant\"}}\n\n")
+	result := rw.rewriteStreamChunk(chunk)
+
+	expected := "data: {\"message\":{\"model\":\"claude-opus-4.5\",\"role\":\"assistant\"}}\n\n"
+	if string(result) != expected {
+		t.Errorf("expected %s, got %s", expected, string(result))
+	}
+}
+
+func contains(data, substr []byte) bool {
+	for i := 0; i <= len(data)-len(substr); i++ {
+		if string(data[i:i+len(substr)]) == string(substr) {
+			return true
+		}
+	}
+	return false
+}