diff --git a/main.go b/main.go
index 41340e3..fb0311d 100644
--- a/main.go
+++ b/main.go
@@ -332,26 +332,46 @@ func main() {
 		cliAgent = ca
 	}
 
-	// One-shot mode
-	if *oneShot != "" {
-		result, err := ag.Run(*oneShot)
+	// One-shot mode and positional-arg mode honour the configured CLI backend.
+	// Prior to the QUA-576 fix these paths always called ag.Run (Anthropic API),
+	// silently ignoring backend=cc and backend=codex — which meant every CI /
+	// scripting / cloud-session invocation bypassed the cc backend and hit the
+	// Anthropic API. Now we route through cliAgent when configured, falling
+	// back to the API agent only when no CLI backend is active.
+	runOneShot := func(prompt string) error {
+		if cliAgent != nil {
+			// CLI backends stream their own output (tool icons, glamour-rendered
+			// text) via the Terminal; FinishMarkdown handles final rendering.
+			// Build a Terminal here since main never created one (repl.Run owns
+			// the interactive Terminal instance).
+			term := tui.NewTerminal()
+			defer term.Close()
+			_, err := cliAgent.Run(prompt, term)
+			return err
+		}
+		// Direct-API path: non-streaming. Print the returned text ourselves.
+		result, err := ag.Run(prompt)
 		if err != nil {
+			return err
+		}
+		fmt.Println(result)
+		return nil
+	}
+
+	if *oneShot != "" {
+		if err := runOneShot(*oneShot); err != nil {
 			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
 			os.Exit(1)
 		}
-		fmt.Println(result)
 		return
 	}
 
 	// Also handle positional args as a prompt: qmax-code "test the login flow"
 	if remaining := flag.Args(); len(remaining) > 0 {
-		prompt := strings.Join(remaining, " ")
-		result, err := ag.Run(prompt)
-		if err != nil {
+		if err := runOneShot(strings.Join(remaining, " ")); err != nil {
 			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
 			os.Exit(1)
 		}
-		fmt.Println(result)
 		return
 	}
 
diff --git a/main_oneshot_test.go b/main_oneshot_test.go
new file mode 100644
index 0000000..cd74358
--- /dev/null
+++ b/main_oneshot_test.go
@@ -0,0 +1,101 @@
+package main
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/qualitymax/qmax-code/internal/agent"
+	"github.com/qualitymax/qmax-code/internal/tui"
+)
+
+// fakeCLIAgent is a tiny CLIAgent implementation that records whether its
+// Run method was called. Used to verify the QUA-576 dispatch fix without
+// needing a real claude/codex binary.
+type fakeCLIAgent struct {
+	called  bool
+	prompt  string
+	result  string
+	runErr  error
+}
+
+func (f *fakeCLIAgent) Run(userMsg string, _ *tui.Terminal) (string, error) {
+	f.called = true
+	f.prompt = userMsg
+	return f.result, f.runErr
+}
+func (f *fakeCLIAgent) Cancel()                {}
+func (f *fakeCLIAgent) Cleanup()               {}
+func (f *fakeCLIAgent) SetOutputVerbose(bool)  {}
+
+// dispatchForTest mirrors the dispatch logic in main.go's `runOneShot`
+// closure. Keeping it in sync with that closure is the regression contract
+// of TestOneShotDispatch_* below.
+//
+// The real closure (main.go) also creates a tui.Terminal when cliAgent is
+// non-nil; for unit testing we pass nil since fakeCLIAgent doesn't use it.
+func dispatchForTest(prompt string, cliAgent agent.CLIAgent, apiCallback func(string) (string, error)) error {
+	if cliAgent != nil {
+		_, err := cliAgent.Run(prompt, nil)
+		return err
+	}
+	_, err := apiCallback(prompt)
+	return err
+}
+
+// TestOneShotDispatch_PrefersCLIAgent is the regression test for QUA-576.
+// Before the fix, -p and positional-arg modes called ag.Run directly even
+// when backend=cc was configured. This test asserts that when a CLIAgent
+// is present, it is the agent that handles the one-shot prompt.
+func TestOneShotDispatch_PrefersCLIAgent(t *testing.T) {
+	fake := &fakeCLIAgent{result: "cli-result"}
+	apiCalled := false
+	apiCallback := func(string) (string, error) {
+		apiCalled = true
+		return "api-result", nil
+	}
+
+	if err := dispatchForTest("hello", fake, apiCallback); err != nil {
+		t.Fatalf("dispatch returned err: %v", err)
+	}
+	if !fake.called {
+		t.Error("expected fakeCLIAgent.Run to be called, but it was not")
+	}
+	if apiCalled {
+		t.Error("expected API callback NOT to be called when cliAgent is set, but it was")
+	}
+	if fake.prompt != "hello" {
+		t.Errorf("prompt passed to CLI agent: got %q, want %q", fake.prompt, "hello")
+	}
+}
+
+// TestOneShotDispatch_FallsBackToAPI confirms the no-CLI-backend fallback.
+func TestOneShotDispatch_FallsBackToAPI(t *testing.T) {
+	apiCalled := false
+	apiCallback := func(string) (string, error) {
+		apiCalled = true
+		return "api-result", nil
+	}
+
+	if err := dispatchForTest("hello", nil, apiCallback); err != nil {
+		t.Fatalf("dispatch returned err: %v", err)
+	}
+	if !apiCalled {
+		t.Error("expected API callback to be called when cliAgent is nil, but it was not")
+	}
+}
+
+// TestOneShotDispatch_PropagatesCLIError ensures errors from the CLI agent
+// surface to the caller (which exits non-zero in main.go).
+func TestOneShotDispatch_PropagatesCLIError(t *testing.T) {
+	want := errors.New("cc subprocess failed")
+	fake := &fakeCLIAgent{runErr: want}
+	apiCallback := func(string) (string, error) {
+		t.Fatal("API callback must not be called when cliAgent is present")
+		return "", nil
+	}
+
+	err := dispatchForTest("hello", fake, apiCallback)
+	if err == nil || err.Error() != want.Error() {
+		t.Errorf("dispatch error: got %v, want %v", err, want)
+	}
+}