diff --git a/argus/harness.py b/argus/harness.py
index 7af7685..36f08da 100644
--- a/argus/harness.py
+++ b/argus/harness.py
@@ -122,7 +122,8 @@ def before_turn(messages):
             if compacted is not messages:
                 messages[:] = compacted
                 if self.persist:
-                    session.append(self.session_path, messages[0])
+                    for message in messages:
+                        session.append(self.session_path, message)
                 recorded_index = len(messages)
             record()
             return messages
diff --git a/argus/loop.py b/argus/loop.py
index 4371e93..6c65d97 100644
--- a/argus/loop.py
+++ b/argus/loop.py
@@ -1,6 +1,7 @@
 """The agent turn loop with explicit tool-error containment."""
 
 from .providers import Provider, ensure_call_ids, get_provider
+from .tools import redact
 
 
 def run(
@@ -63,6 +64,7 @@ def run(
                         result = str(tool.run(**args))
                     except Exception as error:
                         result = f"ERROR: {type(error).__name__}: {error}"
+            result = redact(result)
             messages.append(
                 {
                     "role": "tool",
diff --git a/tests/test_harness.py b/tests/test_harness.py
index ce7cc63..ce7ec6f 100644
--- a/tests/test_harness.py
+++ b/tests/test_harness.py
@@ -106,6 +106,58 @@ def test_compaction_is_persisted_and_reloadable(self):
         self.assertTrue((resumed.messages[0].get("meta") or {}).get("compaction"))
         self.assertEqual(harness.usage, {"input": 2, "output": 2, "total": 4})
 
+    def test_compaction_restores_retained_turns_on_resume(self):
+        provider = ScriptedProvider([
+            reply("", [tool_call("read_file", {"path": "note.txt"}, "c1")]),
+            reply("", [tool_call("read_file", {"path": "note.txt"}, "c2")]),
+            reply("compressed facts"),
+            reply("finished"),
+        ])
+        harness = Harness(
+            self.root, provider=provider, policy=Policy("yolo"),
+            budget_tokens=1,
+        )
+        with mock.patch.object(context, "KEEP_RECENT", 3):
+            self.assertEqual(harness.run("long task"), "finished")
+
+        resumed = Harness(self.root, provider=ScriptedProvider(), persist=False)
+        self.assertTrue(resumed.resume(harness.session_path))
+        self.assertTrue((resumed.messages[0].get("meta") or {}).get("compaction"))
+        assistant_calls = [
+            call
+            for message in resumed.messages
+            if message.get("role") == "assistant"
+            for call in message.get("tool_calls") or []
+        ]
+        tool_rows = [
+            message for message in resumed.messages if message.get("role") == "tool"
+        ]
+        self.assertEqual([call["id"] for call in assistant_calls], ["c2"])
+        self.assertEqual([message["call_id"] for message in tool_rows], ["c2"])
+        self.assertEqual(resumed.messages[-1]["text"], "finished")
+
+    def test_use_skill_output_is_redacted_before_persistence(self):
+        secret = "sk-abcdefghijklmnop1234"
+        skill_dir = os.path.join(self.root, "skills", "demo")
+        os.makedirs(skill_dir)
+        with open(os.path.join(skill_dir, "SKILL.md"), "w", encoding="utf-8") as stream:
+            stream.write(f"---\ndescription: Demo skill\n---\nUse {secret}.\n")
+        provider = ScriptedProvider([
+            reply("", [tool_call("use_skill", {"name": "demo"}, "c1")]),
+            reply("done"),
+        ])
+        harness = Harness(self.root, provider=provider, policy=Policy("yolo"))
+        harness.run("load the demo skill")
+
+        tool_message = next(
+            message for message in harness.messages if message.get("role") == "tool"
+        )
+        self.assertIn("[REDACTED_OPENAI_KEY]", tool_message["text"])
+        with open(harness.session_path, encoding="utf-8") as stream:
+            persisted = stream.read()
+        self.assertNotIn(secret, persisted)
+        self.assertIn("[REDACTED_OPENAI_KEY]", persisted)
+
     def test_remember_tool_writes_and_dedupes(self):
         harness = Harness(
             self.root, provider=ScriptedProvider(), persist=False
diff --git a/tests/test_loop.py b/tests/test_loop.py
index ae903e1..1c4d42f 100644
--- a/tests/test_loop.py
+++ b/tests/test_loop.py
@@ -53,6 +53,23 @@ def test_unknown_tool_is_reported_to_model(self):
         loop.run("system", messages, self.tools, provider=provider)
         self.assertTrue(messages[2]["text"].startswith("ERROR: unknown tool"))
 
+    def test_tool_results_are_redacted_in_history_and_events(self):
+        secret = "sk-abcdefghijklmnop1234"
+        provider = ScriptedProvider([
+            reply("", [tool_call("echo", {"text": secret}, "c1")]),
+            reply("done"),
+        ])
+        messages = [{"role": "user", "text": "go"}]
+        events = []
+        loop.run(
+            "system", messages, self.tools, provider=provider,
+            on_event=lambda kind, payload: events.append((kind, payload)),
+        )
+        self.assertNotIn(secret, messages[2]["text"])
+        self.assertIn("[REDACTED_OPENAI_KEY]", messages[2]["text"])
+        tool_end = next(payload for kind, payload in events if kind == "tool_end")
+        self.assertNotIn(secret, tool_end["result"])
+
     def test_tool_exception_is_contained(self):
         provider = ScriptedProvider([
             reply("", [tool_call("boom", {}, "c1")]),