diff --git a/tests/test_trace.py b/tests/test_trace.py
index 57592d1..cdb7c3e 100644
--- a/tests/test_trace.py
+++ b/tests/test_trace.py
@@ -232,3 +232,82 @@ def msg(eid, parent, role):
         msg("x", "b", "user"), msg("y", "x", "assistant"),        # abandoned
         msg("c", "b", "user"), msg("d", "c", "toolResult"), msg("e", "d", "assistant")])
     assert trace.pi_prompt_count(p) == 2
+
+
+# Valid JSON that is not an object. A reader that takes every line for a record calls `.get` on
+# it. The array holds each marker a reader looks for before it parses a line.
+NON_OBJECT_LINES = [
+    "null", "42", '"text"',
+    '["usage", "session_meta", "turn_context", "token_count", "response_item", '
+    '"session.start", "type", "system"]']
+
+
+def _around_non_objects(records):
+    import json
+    return NON_OBJECT_LINES + [json.dumps(r) for r in records] + NON_OBJECT_LINES
+
+
+def test_a_non_object_line_does_not_discard_the_calls_around_it():
+    claude = {"type": "assistant", "message": {"content": [
+        {"type": "tool_use", "id": "t", "name": "Bash", "input": {"command": "ls"}}]}}
+    codex = {"type": "item.completed",
+             "item": {"type": "command_execution", "command": "ls", "exit_code": 0}}
+    start = {"type": "tool.execution_start",
+             "data": {"toolCallId": "c", "toolName": "bash", "arguments": {"command": "ls"}}}
+    done = {"type": "tool.execution_complete", "data": {"toolCallId": "c", "success": True}}
+    assert [c[:2] for c in trace.claude_calls(_around_non_objects([claude]))] == [
+        ("Bash", {"command": "ls"})]
+    assert [c[:2] for c in trace.codex_exec_calls(_around_non_objects([codex]))] == [
+        ("shell", {"command": "ls"})]
+    assert [c[:2] for c in trace.copilot_event_calls(_around_non_objects([start, done]))] == [
+        ("bash", {"command": "ls"})]
+
+
+def test_a_non_object_line_does_not_stop_a_session_from_being_read(tmp_path):
+    from tokeneconomizer.trace.copilot import copilot_session_cwd
+    claude = {"type": "assistant", "message": {"id": "m1", "usage": {"input_tokens": 5}}}
+    meta = {"type": "session_meta", "payload": {"cwd": "/w", "cli_version": "1.0"}}
+    count = {"type": "event_msg", "payload": {"type": "token_count", "info": {
+        "total_token_usage": {"input_tokens": 10, "cached_input_tokens": 4,
+                              "output_tokens": 3}}}}
+    start = {"type": "session.start", "data": {"context": {"cwd": "/repo"}}}
+    p = tmp_path / "claude.jsonl"
+    p.write_text("\n".join(_around_non_objects([claude])))
+    assert trace.claude_session_usage(str(p))["input_tokens"] == 5
+    r = tmp_path / "rollout.jsonl"
+    r.write_text("\n".join(_around_non_objects([meta, count])))
+    assert trace.codex_session_meta(str(r)) == {"cwd": "/w", "cli_version": "1.0"}
+    usage = trace.codex_session_usage(str(r))
+    assert (usage["input_tokens"], usage["output_tokens"], usage["requests"]) == (6, 3, 1)
+    assert copilot_session_cwd(_around_non_objects([start])) == "/repo"
+
+
+def test_a_non_object_line_does_not_stop_a_rollout_from_being_converted(tmp_path):
+    done = {"type": "event_msg", "payload": {"type": "item_completed", "item": {
+        "type": "CommandExecution", "command": ["ls"], "exit_code": 0}}}
+    call = {"type": "response_item", "payload": {
+        "type": "function_call", "name": "x", "call_id": "c", "arguments": "{}"}}
+    r, out = tmp_path / "rollout.jsonl", tmp_path / "exec.jsonl"
+    r.write_text("\n".join(_around_non_objects([done, call])))
+    assert trace.codex_rollout_to_exec(str(r), str(out)) == 1
+    assert trace.codex_capability_trace(str(r), str(out)) == 2
+
+
+def test_a_non_object_line_does_not_empty_a_tool_catalog():
+    system = {"type": "system", "tools": ["Bash"]}
+    checkpoint = {"type": "session.usage_checkpoint", "data": {"promptCacheBreakState": [
+        {"models": {"m": {"tools": [{"name": "view"}]}}}]}}
+    text = "\n".join(_around_non_objects([system]))
+    assert trace.parse_tool_catalog_claude(text, snapshot={}) == {"Bash": ""}
+    text = "\n".join(_around_non_objects([checkpoint]))
+    assert trace.parse_tool_names_copilot(text) == {"view": ""}
+
+
+def test_the_loop_guard_and_the_capability_audit_skip_a_non_object_line(tmp_path):
+    from tokeneconomizer.loopguard.state import completed_calls
+    from tokeneconomizer.toolprune.codex import inspect_usage
+    assert [completed_calls(line, {}) for line in NON_OBJECT_LINES] == [[]] * 4
+    reconnect = {"type": "error", "message": "Reconnecting... 1/5"}
+    p = tmp_path / "exec.jsonl"
+    p.write_text("\n".join(_around_non_objects([reconnect])))
+    assert inspect_usage(str(p))["reconnects"] == 1
diff --git a/tokeneconomizer/loopguard/state.py b/tokeneconomizer/loopguard/state.py
index 722f8d2..9763be3 100644
--- a/tokeneconomizer/loopguard/state.py
+++ b/tokeneconomizer/loopguard/state.py
@@ -63,6 +63,8 @@ def completed_calls(line, pend):
         ev = json.loads(line)
     except Exception:
         return []
+    if not isinstance(ev, dict):
+        return []
     t = ev.get("type")
     out = []
     # ---- Codex exec --json schema ----
diff --git a/tokeneconomizer/toolprune/codex.py b/tokeneconomizer/toolprune/codex.py
index 4cab69c..78b1e14 100644
--- a/tokeneconomizer/toolprune/codex.py
+++ b/tokeneconomizer/toolprune/codex.py
@@ -208,6 +208,8 @@ def inspect_usage(transcript_path):
                     event = json.loads(line)
                 except Exception:
                     continue
+                if not isinstance(event, dict):
+                    continue
                 phase = str(event.get("type") or "")
                 if phase == "error" and "reconnecting" in str(
                         event.get("message") or event.get("error") or "").lower():
diff --git a/tokeneconomizer/trace/catalog.py b/tokeneconomizer/trace/catalog.py
index 7dfcd87..fbcf357 100644
--- a/tokeneconomizer/trace/catalog.py
+++ b/tokeneconomizer/trace/catalog.py
@@ -127,7 +127,8 @@ def parse_tool_catalog_claude(transcript_text, max_desc=200, snapshot=None):
             ev = json.loads(line)
         except Exception:
             continue
-        if ev.get("type") == "system" and isinstance(ev.get("tools"), list):
+        if isinstance(ev, dict) and ev.get("type") == "system" and isinstance(
+                ev.get("tools"), list):
             names = ev["tools"]
             break
     return {n: (snap.get(n, "") or "")[:max_desc] for n in names}
@@ -204,6 +205,8 @@ def parse_tool_names_copilot(transcript_text):
             ev = json.loads(line)
         except Exception:
             continue
+        if not isinstance(ev, dict):
+            continue
         for pcb in ((ev.get("data") or {}).get("promptCacheBreakState") or []):
             for model in (pcb.get("models") or {}).values():
                 for tool in (model.get("tools") or []):
diff --git a/tokeneconomizer/trace/claude.py b/tokeneconomizer/trace/claude.py
index 3fe97ce..d6c6dcd 100644
--- a/tokeneconomizer/trace/claude.py
+++ b/tokeneconomizer/trace/claude.py
@@ -33,6 +33,8 @@ def claude_calls(lines):
             ev = json.loads(line)
         except Exception:
             continue
+        if not isinstance(ev, dict):
+            continue
         if ev.get("type", "assistant") not in CONVERSATION:
             continue
         msg = ev.get("message") or {}
@@ -293,7 +295,7 @@ def claude_session_usage(transcript_path, include_subagents=True):
                 ev = json.loads(line)
             except ValueError:
                 continue
-            if ev.get("type") != "assistant":
+            if not isinstance(ev, dict) or ev.get("type") != "assistant":
                 continue
             msg = ev.get("message") or {}
             usage = msg.get("usage")
diff --git a/tokeneconomizer/trace/codex.py b/tokeneconomizer/trace/codex.py
index 5754091..5e34060 100644
--- a/tokeneconomizer/trace/codex.py
+++ b/tokeneconomizer/trace/codex.py
@@ -46,7 +46,7 @@ def codex_exec_calls(lines):
             ev = json.loads(line)
         except Exception:
             continue
-        if ev.get("type") != "item.completed":
+        if not isinstance(ev, dict) or ev.get("type") != "item.completed":
             continue
         item = ev.get("item") or {}
         kind = item.get("type")
@@ -148,6 +148,8 @@ def codex_rollout_to_exec(rollout_path, out_path):
                 ev = json.loads(line)
             except ValueError:
                 continue
+            if not isinstance(ev, dict):
+                continue
             payload = ev.get("payload") if isinstance(ev.get("payload"), dict) else {}
             if ev.get("type") == "session_meta" and thread is None:
                 thread = payload.get("id") or payload.get("session_id")
@@ -184,6 +186,8 @@ def codex_capability_trace(rollout_path, out_path):
                 ev = json.loads(line)
             except ValueError:
                 continue
+            if not isinstance(ev, dict):
+                continue
             p = ev.get("payload") if isinstance(ev.get("payload"), dict) else {}
             if ev.get("type") != "response_item" or p.get("type") not in (
                     "custom_tool_call", "function_call"):
@@ -226,6 +230,8 @@ def codex_session_meta(rollout_path):
             ev = json.loads(line)
         except ValueError:
             continue
+        if not isinstance(ev, dict):
+            continue
         p = ev.get("payload") if isinstance(ev.get("payload"), dict) else {}
         if ev.get("type") == "session_meta":
             meta.setdefault("cwd", p.get("cwd"))
@@ -249,6 +255,8 @@ def codex_session_usage(rollout_path):
             ev = json.loads(line)
         except ValueError:
             continue
+        if not isinstance(ev, dict):
+            continue
         p = ev.get("payload") if isinstance(ev.get("payload"), dict) else {}
         if p.get("type") != "token_count":
             continue
diff --git a/tokeneconomizer/trace/copilot.py b/tokeneconomizer/trace/copilot.py
index bd305db..909ed52 100644
--- a/tokeneconomizer/trace/copilot.py
+++ b/tokeneconomizer/trace/copilot.py
@@ -32,6 +32,8 @@ def copilot_event_calls(lines):
             ev = json.loads(line)
         except Exception:
             continue
+        if not isinstance(ev, dict):
+            continue
         t = ev.get("type")
         d = ev.get("data", {}) if isinstance(ev.get("data"), dict) else {}
         if t == "tool.execution_start":
@@ -53,9 +55,12 @@ def copilot_session_cwd(lines):
         if '"session.start"' not in line:
             continue
         try:
-            d = json.loads(line).get("data") or {}
+            ev = json.loads(line)
         except ValueError:
             continue
+        if not isinstance(ev, dict):
+            continue
+        d = ev.get("data") or {}
         cwd = (d.get("context") or {}).get("cwd")
         return cwd if isinstance(cwd, str) else None
     return None