diff --git a/internal/runtime/executor/codex_executor_stream_output_test.go b/internal/runtime/executor/codex_executor_stream_output_test.go
index 477a9800a..46a43de39 100644
--- a/internal/runtime/executor/codex_executor_stream_output_test.go
+++ b/internal/runtime/executor/codex_executor_stream_output_test.go
@@ -18,6 +18,43 @@ import (
 	"github.com/tidwall/gjson"
 )
 
+func TestCodexExecutorExecute_NonEmptyCompletionOutputHydratesMissingItemID(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/event-stream")
+		_, _ = w.Write([]byte(`data: {"type":"response.output_item.done","item":{"id":"fc_123","type":"function_call","call_id":"call_123","name":"weather","arguments":"{}"},"output_index":0}` + "\n\n"))
+		_, _ = w.Write([]byte(`data: {"type":"response.output_item.done","item":{"id":"fc_done_existing","type":"function_call","call_id":"call_existing","name":"other","arguments":"{}"},"output_index":1}` + "\n\n"))
+		_, _ = w.Write([]byte(`data: {"type":"response.completed","response":{"id":"resp_1","object":"response","status":"completed","output":[{"id":null,"type":"function_call","call_id":"call_123","name":"weather-terminal","arguments":"{}"},{"id":"fc_existing","type":"function_call","call_id":"call_existing","name":"preserved","arguments":"{}"}]}}` + "\n\n"))
+	}))
+	defer server.Close()
+
+	executor := NewCodexExecutor(&config.Config{})
+	auth := &cliproxyauth.Auth{Attributes: map[string]string{
+		"base_url": server.URL,
+		"api_key":  "test",
+	}}
+
+	resp, err := executor.Execute(context.Background(), auth, cliproxyexecutor.Request{
+		Model:   "gpt-5.4",
+		Payload: []byte(`{"model":"gpt-5.4","input":"What is the weather?"}`),
+	}, cliproxyexecutor.Options{
+		SourceFormat: sdktranslator.FromString("openai-response"),
+		Stream:       false,
+	})
+	if err != nil {
+		t.Fatalf("Execute error: %v", err)
+	}
+
+	if got := gjson.GetBytes(resp.Payload, "output.0.id").String(); got != "fc_123" {
+		t.Fatalf("output[0].id = %q, want %q; payload=%s", got, "fc_123", resp.Payload)
+	}
+	if got := gjson.GetBytes(resp.Payload, "output.0.name").String(); got != "weather-terminal" {
+		t.Fatalf("output[0].name = %q, want terminal value; payload=%s", got, resp.Payload)
+	}
+	if got := gjson.GetBytes(resp.Payload, "output.1.id").String(); got != "fc_existing" {
+		t.Fatalf("output[1].id = %q, want existing value; payload=%s", got, resp.Payload)
+	}
+}
+
 func TestCodexExecutorExecute_EmptyStreamCompletionOutputUsesOutputItemDone(t *testing.T) {
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "text/event-stream")
diff --git a/internal/runtime/executor/codex_executor_terminal.go b/internal/runtime/executor/codex_executor_terminal.go
index 3ebc3d4ec..b2845f928 100644
--- a/internal/runtime/executor/codex_executor_terminal.go
+++ b/internal/runtime/executor/codex_executor_terminal.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"net/http"
 	"sort"
+	"strconv"
 	"strings"
 	"time"
 
@@ -44,8 +45,39 @@ func collectCodexOutputItemDone(eventData []byte, outputItemsByIndex map[int64][
 	*outputItemsFallback = append(*outputItemsFallback, []byte(itemResult.Raw))
 }
 
+func hydrateCodexCompletedOutputItemIDs(eventData []byte, outputItems []gjson.Result, outputItemsByIndex map[int64][]byte) []byte {
+	patchedData := eventData
+	for outputIndex, outputItem := range outputItems {
+		itemData := []byte(outputItem.Raw)
+		itemID := gjson.GetBytes(itemData, "id")
+		if itemID.Exists() && itemID.Type != gjson.Null && (itemID.Type != gjson.String || strings.TrimSpace(itemID.String()) != "") {
+			continue
+		}
+
+		completedItem, ok := outputItemsByIndex[int64(outputIndex)]
+		if !ok {
+			continue
+		}
+		completedID := gjson.GetBytes(completedItem, "id")
+		if completedID.Type != gjson.String || strings.TrimSpace(completedID.String()) == "" {
+			continue
+		}
+
+		updatedData, errSet := sjson.SetRawBytes(patchedData, "response.output."+strconv.Itoa(outputIndex)+".id", []byte(completedID.Raw))
+		if errSet != nil {
+			continue
+		}
+		patchedData = updatedData
+	}
+	return patchedData
+}
+
 func patchCodexCompletedOutput(eventData []byte, outputItemsByIndex map[int64][]byte, outputItemsFallback [][]byte) []byte {
 	outputResult := gjson.GetBytes(eventData, "response.output")
+	if outputResult.Exists() && outputResult.IsArray() && len(outputResult.Array()) > 0 {
+		return hydrateCodexCompletedOutputItemIDs(eventData, outputResult.Array(), outputItemsByIndex)
+	}
+
 	shouldPatchOutput := (!outputResult.Exists() || !outputResult.IsArray() || len(outputResult.Array()) == 0) && (len(outputItemsByIndex) > 0 || len(outputItemsFallback) > 0)
 	if !shouldPatchOutput {
 		return eventData