From 12d29e42da9b2fd2095a8074fb6ca02060b48369 Mon Sep 17 00:00:00 2001
From: Franco Conturso <contursofran@gmail.com>
Date: Fri, 13 Nov 2026 17:01:25 -0300
Subject: [PATCH] Prompt hook: print nothing for a prompt with only task
 notifications or hc notes (#759)

---
 cmd/contr/hooksession.go      | 12 +++++++++++-
 cmd/contr/hooksession_test.go | 18 ++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/cmd/contr/hooksession.go b/cmd/contr/hooksession.go
index 67e6df9c..55ecfc82 100644
--- a/cmd/contr/hooksession.go
+++ b/cmd/contr/hooksession.go
@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"regexp"
 	"runtime"
 	"strings"
 	"time"
@@ -95,7 +96,7 @@ func promptHook(stdin io.Reader, stdout, stderr io.Writer, stateDir, id string,
 		return nil
 	}
 	text := youContext
-	if strings.HasPrefix(strings.TrimSpace(in.Prompt), "<hc from=") || strings.TrimSpace(in.Prompt) == "" {
+	if !ownerWords(in.Prompt) {
 		text = ""
 	}
 	if flow != "" {
@@ -107,6 +108,15 @@ func promptHook(stdin io.Reader, stdout, stderr io.Writer, stateDir, id string,
 	return writeContext(stdout, "UserPromptSubmit", text)
 }
 
+// notePattern matches the blocks of a prompt that hold no request of the
+// owner: a background-task notification, a system reminder and an hc note.
+var notePattern = regexp.MustCompile(`(?s)<task-notification>.*?</task-notification>|</?system-reminder>|<hc from="[^"]*">.*?</hc>`)
+
+// ownerWords reports whether the prompt holds text other than notes.
+func ownerWords(prompt string) bool {
+	return strings.TrimSpace(notePattern.ReplaceAllString(prompt, "")) != ""
+}
+
 func postToolHook(stdin io.Reader, stateDir, id string, now uint64) error {
 	var in toolInput
 	if err := json.NewDecoder(stdin).Decode(&in); err != nil {
diff --git a/cmd/contr/hooksession_test.go b/cmd/contr/hooksession_test.go
index f5ff3215..30bc6956 100644
--- a/cmd/contr/hooksession_test.go
+++ b/cmd/contr/hooksession_test.go
@@ -124,6 +124,24 @@ func TestPromptHook(t *testing.T) {
 	if out, _ := runSession(t, dir, "prompt", `{"prompt":"<hc from=\"t2\">done</hc>"}`); out != "" {
 		t.Fatalf("hc report got %q", out)
 	}
+	for _, p := range []string{
+		`<task-notification>\n<task-id>b1</task-id>\n</task-notification>`,
+		`<system-reminder>\n<task-notification>done</task-notification>\n</system-reminder>`,
+		`<hc from=\"t2\">a</hc>\n<hc from=\"t3\">b</hc>`,
+		`  `,
+	} {
+		if out, _ := runSession(t, dir, "prompt", `{"prompt":"`+p+`"}`); out != "" {
+			t.Fatalf("note %q got %q", p, out)
+		}
+	}
+	for _, p := range []string{
+		`<task-notification>done</task-notification>\nnow fix the bug`,
+		`<hc from=\"t2\">done</hc> merge it`,
+	} {
+		if out, _ := runSession(t, dir, "prompt", `{"prompt":"`+p+`"}`); !strings.Contains(out, `[you]`) {
+			t.Fatalf("owner words %q got %q", p, out)
+		}
+	}
 	if _, e := runSession(t, dir, "prompt", `nope`); !strings.Contains(e, "bad hook input") {
 		t.Fatalf("stderr %q", e)
 	}