diff --git a/internal/runtime/executor/codex_executor.go b/internal/runtime/executor/codex_executor.go
index 399368125..73187963c 100644
--- a/internal/runtime/executor/codex_executor.go
+++ b/internal/runtime/executor/codex_executor.go
@@ -465,7 +465,17 @@ func filterCodexReasoningReplayItemsForInput(body []byte, items [][]byte) [][]by
 
 	hasInputReasoning := codexInputHasValidReasoningEncryptedContent(body)
 	existingCalls := make(map[string]bool)
+	existingOutputs := make(map[string]bool)
 	for _, inputItem := range input.Array() {
+		itemType := strings.TrimSpace(inputItem.Get("type").String())
+		if itemType == "function_call_output" || itemType == "custom_tool_call_output" {
+			callID := strings.TrimSpace(inputItem.Get("call_id").String())
+			if callID != "" {
+				for _, candidate := range codexReplayComparableCallIDs(callID) {
+					existingOutputs[candidate] = true
+				}
+			}
+		}
 		for _, key := range codexReplayToolCallKeys(inputItem) {
 			existingCalls[key] = true
 		}
@@ -484,6 +494,20 @@ func filterCodexReasoningReplayItemsForInput(body []byte, items [][]byte) [][]by
 			if len(keys) == 0 || codexReplayAnyToolCallKeyExists(existingCalls, keys) {
 				continue
 			}
+			// Only inject if there is a matching output in the request
+			hasMatchingOutput := false
+			callID := strings.TrimSpace(itemResult.Get("call_id").String())
+			if callID != "" {
+				for _, candidate := range codexReplayComparableCallIDs(callID) {
+					if existingOutputs[candidate] {
+						hasMatchingOutput = true
+						break
+					}
+				}
+			}
+			if !hasMatchingOutput {
+				continue
+			}
 			for _, key := range keys {
 				existingCalls[key] = true
 			}
diff --git a/internal/runtime/executor/codex_executor_reasoning_replay_cache_test.go b/internal/runtime/executor/codex_executor_reasoning_replay_cache_test.go
index a15007ed3..8c94b146b 100644
--- a/internal/runtime/executor/codex_executor_reasoning_replay_cache_test.go
+++ b/internal/runtime/executor/codex_executor_reasoning_replay_cache_test.go
@@ -710,6 +710,54 @@ func TestCodexExecutorReasoningReplayCacheReplaysFunctionCallForClaudeToolResult
 	}
 }
 
+func TestCodexExecutorReasoningReplayCacheDropsFunctionCallWithoutMatchingOutput(t *testing.T) {
+	internalcache.ClearCodexReasoningReplayCache()
+	t.Cleanup(internalcache.ClearCodexReasoningReplayCache)
+
+	encryptedContent := validCodexReasoningEncryptedContentForTestSeed(14)
+	scope := codexReasoningReplayScope{
+		modelName:  "gpt-5.4",
+		sessionKey: "claude:session-dropped-tool",
+	}
+	cacheCodexReasoningReplayFromCompleted(scope, []byte(`{"response":{"output":[`+
+		`{"type":"reasoning","summary":[],"content":null,"encrypted_content":"`+encryptedContent+`"},`+
+		`{"type":"function_call","call_id":"call_dropped","name":"TaskCreate","arguments":"{}"}`+
+		`]}}`))
+
+	body := []byte(`{"model":"gpt-5.4","input":[{"type":"message","role":"user","content":[{"type":"input_text","text":"next"}]}]}`)
+	req := cliproxyexecutor.Request{
+		Model: "gpt-5.4",
+		Payload: []byte(`{
+			"model":"gpt-5.4",
+			"metadata":{"user_id":"{\"device_id\":\"device-test\",\"account_uuid\":\"\",\"session_id\":\"session-dropped-tool\"}"},
+			"messages":[{"role":"user","content":[{"type":"text","text":"next"}]}]
+		}`),
+	}
+
+	updated, replayScope := applyCodexReasoningReplayCache(
+		context.Background(),
+		sdktranslator.FromString("claude"),
+		req,
+		cliproxyexecutor.Options{SourceFormat: sdktranslator.FromString("claude")},
+		body,
+	)
+	if replayScope != scope {
+		t.Fatalf("replay scope = %#v, want %#v", replayScope, scope)
+	}
+	if got := gjson.GetBytes(updated, "input.0.type").String(); got != "reasoning" {
+		t.Fatalf("input.0.type = %q, want reasoning; body=%s", got, string(updated))
+	}
+	if got := gjson.GetBytes(updated, "input.0.encrypted_content").String(); got != encryptedContent {
+		t.Fatalf("input.0.encrypted_content = %q, want cached reasoning; body=%s", got, string(updated))
+	}
+	if gjson.GetBytes(updated, `input.#(call_id=="call_dropped")`).Exists() {
+		t.Fatalf("cached function_call without matching output should not be replayed; body=%s", string(updated))
+	}
+	if got := gjson.GetBytes(updated, "input.1.role").String(); got != "user" {
+		t.Fatalf("input.1.role = %q, want user; body=%s", got, string(updated))
+	}
+}
+
 func TestCodexExecutorReasoningReplayCacheMatchesShortenedClaudeToolResultCallID(t *testing.T) {
 	internalcache.ClearCodexReasoningReplayCache()
 	t.Cleanup(internalcache.ClearCodexReasoningReplayCache)