allow new/old session dates, tool call export errors

src/fast_agent/session/snapshot.py

@@ -5,7 +5,7 @@
 import json
 import warnings
 from collections.abc import Mapping
-from datetime import datetime
+from datetime import datetime, timezone
 from pathlib import Path
 from typing import TYPE_CHECKING, Literal, Protocol, runtime_checkable
 
@@ -207,7 +207,10 @@ def load_session_snapshot(payload: object) -> SessionSnapshot:
         return synthesize_legacy_session_snapshot(payload_mapping)
     if raw_schema_version != SESSION_SNAPSHOT_SCHEMA_VERSION:
         raise ValueError(f"Unsupported session snapshot schema version: {raw_schema_version!r}")
-    return SessionSnapshot.model_validate(payload_mapping)
+    snapshot = SessionSnapshot.model_validate(payload_mapping)
+    snapshot.created_at = _normalize_session_timestamp(snapshot.created_at)
+    snapshot.last_activity = _normalize_session_timestamp(snapshot.last_activity)
+    return snapshot
 
 
 def synthesize_legacy_session_snapshot(payload: Mapping[str, object]) -> SessionSnapshot:
@@ -411,10 +414,10 @@ def _legacy_timestamp(
     fallback: datetime,
 ) -> datetime:
     if isinstance(value, datetime):
-        return value
+        return _normalize_session_timestamp(value)
     if isinstance(value, str):
         try:
-            return datetime.fromisoformat(value)
+            return _normalize_session_timestamp(datetime.fromisoformat(value))
         except ValueError:
             _warn_legacy_issue(
                 session_id,
@@ -429,6 +432,12 @@ def _legacy_timestamp(
     return fallback
 
 
+def _normalize_session_timestamp(value: datetime) -> datetime:
+    if value.tzinfo is None or value.utcoffset() is None:
+        return value
+    return value.astimezone(timezone.utc).replace(tzinfo=None)
+
+
 def _legacy_metadata_extras(
     metadata: Mapping[str, object] | None,
     session_id: str,

src/fast_agent/session/trace_export_codex.py

@@ -348,6 +348,10 @@ def flush_text_parts() -> None:
     return ""
 
 
+def _tool_result_status(result: CallToolResult) -> str:
+    return "error" if result.isError else "success"
+
+
 def _object_mapping(value: object) -> dict[str, object] | None:
     if not isinstance(value, dict):
         return None
@@ -508,6 +512,7 @@ def _function_call_output_items(message: PromptMessageExtended) -> list[dict[str
                 "type": "function_call_output",
                 "call_id": call_id,
                 "output": _tool_result_output(result),
+                "status": _tool_result_status(result),
             }
         )
     return items

tests/unit/fast_agent/session/test_session_manager.py

@@ -234,6 +234,38 @@ def test_load_session_marks_loaded_session_as_latest(tmp_path) -> None:
         reset_session_manager()
 
 
+def test_list_sessions_normalizes_timezone_aware_timestamps(tmp_path) -> None:
+    manager = SessionManager(
+        cwd=tmp_path,
+        environment_override=tmp_path / ".fast-agent",
+        respect_env_override=False,
+    )
+    older = manager.create_session()
+    newer = manager.create_session()
+
+    older_payload = json.loads((older.directory / "session.json").read_text(encoding="utf-8"))
+    older_payload["created_at"] = "2026-04-22T21:00:41.016804"
+    older_payload["last_activity"] = "2026-04-22T21:00:41.016804"
+    (older.directory / "session.json").write_text(
+        json.dumps(older_payload, indent=2),
+        encoding="utf-8",
+    )
+
+    newer_payload = json.loads((newer.directory / "session.json").read_text(encoding="utf-8"))
+    newer_payload["created_at"] = "2026-04-22T21:01:41.016804Z"
+    newer_payload["last_activity"] = "2026-04-22T21:01:41.016804Z"
+    (newer.directory / "session.json").write_text(
+        json.dumps(newer_payload, indent=2),
+        encoding="utf-8",
+    )
+
+    sessions = manager.list_sessions()
+
+    assert [session.name for session in sessions] == [newer.info.name, older.info.name]
+    assert sessions[0].created_at.tzinfo is None
+    assert sessions[0].last_activity.tzinfo is None
+
+
 @pytest.mark.asyncio
 async def test_resume_session_agents_uses_hydrator_active_agent_and_prompt_restore(
     tmp_path,

tests/unit/fast_agent/session/test_trace_exporter.py

@@ -36,7 +36,7 @@
     SessionExportWriteError,
 )
 from fast_agent.session.trace_export_models import DatasetUploadResult, ExportRequest
-from fast_agent.types import LlmStopReason
+from fast_agent.types import FINAL_ANSWER_PHASE, LlmStopReason
 
 
 def _write_session_snapshot(
@@ -185,6 +185,7 @@ def test_session_trace_exporter_writes_codex_trace(tmp_path: Path) -> None:
     assert records[7]["payload"]["role"] == "assistant"
     assert records[7]["payload"]["content"] == [{"type": "output_text", "text": "done"}]
     assert records[7]["payload"]["end_turn"] is True
+    assert "phase" not in records[7]["payload"]
     assert records[8]["type"] == "event_msg"
     assert "timestamp" not in records[8]
     assert records[8]["payload"]["type"] == "turn_complete"
@@ -408,12 +409,119 @@ def test_session_trace_exporter_writes_native_codex_tool_items(tmp_path: Path) -
         "type": "function_call_output",
         "call_id": "call_1",
         "output": "process exit code was 0",
+        "status": "success",
     }
     assert records[6]["type"] == "event_msg"
     assert records[6]["payload"]["type"] == "turn_complete"
     assert records[6]["payload"]["last_agent_message"] == "Using tools"
 
 
+def test_session_trace_exporter_marks_tool_errors_in_codex_output(tmp_path: Path) -> None:
+    manager = _build_manager(tmp_path)
+    session_id = "2604201303-x5MNlH"
+    session_dir = manager.base_dir / session_id
+    session_dir.mkdir(parents=True)
+    messages = [
+        PromptMessageExtended(
+            role="assistant",
+            content=[TextContent(type="text", text="Using tools")],
+            tool_calls={
+                "call_1": CallToolRequest(
+                    method="tools/call",
+                    params=CallToolRequestParams(
+                        name="execute",
+                        arguments={"command": "false"},
+                    ),
+                )
+            },
+            stop_reason=LlmStopReason.TOOL_USE,
+        ),
+        PromptMessageExtended(
+            role="user",
+            content=[],
+            tool_results={
+                "call_1": CallToolResult(
+                    content=[TextContent(type="text", text="process exit code was 1")],
+                    isError=True,
+                )
+            },
+        ),
+    ]
+    save_json(messages, str(session_dir / "history_dev.json"))
+    _write_session_snapshot(
+        session_dir,
+        session_id=session_id,
+        active_agent="dev",
+        agents={"dev": SessionAgentSnapshot(history_file="history_dev.json")},
+    )
+
+    exporter = SessionTraceExporter(session_manager=manager)
+    exporter.export(
+        ExportRequest(
+            target=session_dir,
+            agent_name="dev",
+            output_path=tmp_path / "trace.jsonl",
+        )
+    )
+
+    records = [
+        json.loads(line)
+        for line in (tmp_path / "trace.jsonl").read_text(encoding="utf-8").splitlines()
+    ]
+
+    assert records[5]["type"] == "response_item"
+    assert records[5]["payload"] == {
+        "type": "function_call_output",
+        "call_id": "call_1",
+        "output": "process exit code was 1",
+        "status": "error",
+    }
+
+
+def test_session_trace_exporter_preserves_explicit_assistant_phase(tmp_path: Path) -> None:
+    manager = _build_manager(tmp_path)
+    session_id = "2604201303-x5MNlH"
+    session_dir = manager.base_dir / session_id
+    session_dir.mkdir(parents=True)
+    messages = [
+        PromptMessageExtended(
+            role="user",
+            content=[TextContent(type="text", text="hello")],
+        ),
+        PromptMessageExtended(
+            role="assistant",
+            content=[TextContent(type="text", text="done")],
+            phase=FINAL_ANSWER_PHASE,
+            stop_reason=LlmStopReason.END_TURN,
+        ),
+    ]
+    save_json(messages, str(session_dir / "history_dev.json"))
+    _write_session_snapshot(
+        session_dir,
+        session_id=session_id,
+        active_agent="dev",
+        agents={"dev": SessionAgentSnapshot(history_file="history_dev.json")},
+    )
+
+    exporter = SessionTraceExporter(session_manager=manager)
+    exporter.export(
+        ExportRequest(
+            target=session_dir,
+            agent_name="dev",
+            output_path=tmp_path / "trace.jsonl",
+        )
+    )
+
+    records = [
+        json.loads(line)
+        for line in (tmp_path / "trace.jsonl").read_text(encoding="utf-8").splitlines()
+    ]
+
+    assert records[5]["payload"]["type"] == "message"
+    assert records[5]["payload"]["role"] == "assistant"
+    assert records[5]["payload"]["phase"] == FINAL_ANSWER_PHASE
+
+
 def test_session_trace_exporter_serializes_zero_argument_tool_calls_as_empty_object(
     tmp_path: Path,
 ) -> None:
@@ -736,6 +844,7 @@ def test_session_trace_exporter_preserves_non_text_tool_outputs(tmp_path: Path)
                 "file_data": "d2F2",
             },
         ],
+        "status": "success",
     }
 
 
@@ -826,6 +935,7 @@ def test_session_trace_exporter_preserves_tool_output_item_order(tmp_path: Path)
                 "file_url": "https://example.com/audio.mp3",
             },
         ],
+        "status": "success",
     }
 
 
@@ -893,6 +1003,7 @@ def test_session_trace_exporter_preserves_user_content_alongside_tool_outputs(tm
         "type": "function_call_output",
         "call_id": "call_1",
         "output": "process exit code was 0",
+        "status": "success",
     }