fix(tui): show log timestamps on the viewer's local clock

backend/app/services/claude_code.py

@@ -620,10 +620,11 @@ async def _crash_backoff_and_wait(
     )
     if publisher is not None:
         publisher.publish_line_nowait("error", error_message)
+        # Relative wait only — the container clock is not the TUI viewer's; the
+        # absolute instant stays on the event's ``next_attempt_at``.
         publisher.publish_line_nowait(
             "system",
-            f"waiting {_format_wait(wait)} before retry ({resume.describe()}), "
-            f"next attempt at {next_attempt_at:%H:%M} UTC",
+            f"waiting {_format_wait(wait)} before retry ({resume.describe()})",
         )
     await set_workspace_retry_state_safe(WorkspaceAgentState.RETRYING)
     await asyncio.sleep(wait.total_seconds())

mcp_server/tests/conftest.py

@@ -0,0 +1,30 @@
+"""Shared fixtures for the MCP server test suite."""
+
+import os
+import time
+from contextlib import contextmanager
+from typing import Iterator
+
+import pytest
+
+
+@contextmanager
+def _pinned_timezone(name: str) -> Iterator[None]:
+    """Run the block with the process timezone pinned, so local-time assertions are stable."""
+    previous = os.environ.get("TZ")
+    os.environ["TZ"] = name
+    time.tzset()
+    try:
+        yield
+    finally:
+        if previous is None:
+            os.environ.pop("TZ", None)
+        else:
+            os.environ["TZ"] = previous
+        time.tzset()
+
+
+@pytest.fixture
+def local_timezone():
+    """Context-manager factory pinning the local timezone (see ``_pinned_timezone``)."""
+    return _pinned_timezone

mcp_server/tests/test_tui_app.py

@@ -243,6 +243,31 @@ def test_uses_pipeline_step_defs_for_checkpoint_label(self):
         assert "Contract validated" in label
         assert "est-d67dcac6cbe5" in label
 
+    def test_created_at_shown_in_local_time(self, local_timezone):
+        with local_timezone("Europe/Warsaw"):  # UTC+2 in July
+            label = tui_app._session_label(
+                {
+                    "generation_id": "est-d67dcac6cbe5",
+                    "status": "running",
+                    "checkpoint": "contract_validated",
+                    "created_at": "2026-07-07T14:00:15.701099+00:00",
+                }
+            )
+
+        assert "Jul 07 16:00" in label
+
+    def test_unparseable_created_at_falls_back_to_raw_prefix(self):
+        label = tui_app._session_label(
+            {
+                "generation_id": "est-d67dcac6cbe5",
+                "status": "running",
+                "checkpoint": "contract_validated",
+                "created_at": "not-a-timestamp-value",
+            }
+        )
+
+        assert "not-a-timestamp" in label
+
     def test_unknown_checkpoint_falls_back_to_key(self):
         label = tui_app._session_label(
             {

mcp_server/tests/test_tui_render.py

@@ -248,12 +248,45 @@ def __init__(self, **kw):
         self.subagent_name = kw.get("subagent_name")
 
 
+class TestFormatLocal:
+    """Backend timestamps are UTC; the TUI must show them on the viewer's clock."""
+
+    def test_utc_timestamp_shown_in_local_time(self, local_timezone):
+        with local_timezone("Europe/Warsaw"):  # UTC+2 in July
+            assert render.format_local("2026-07-28T15:24:05+00:00") == "17:24:05"
+
+    def test_offset_naive_timestamp_read_as_utc(self, local_timezone):
+        with local_timezone("Europe/Warsaw"):
+            assert render.format_local("2026-07-28T15:24:05") == "17:24:05"
+
+    def test_non_utc_offset_converted_to_local(self, local_timezone):
+        with local_timezone("Europe/Warsaw"):  # 15:24+05:00 is 10:24 UTC is 12:24 local
+            assert render.format_local("2026-07-28T15:24:05+05:00") == "12:24:05"
+
+    def test_date_format_rolls_over_with_local_day(self, local_timezone):
+        with local_timezone("Europe/Warsaw"):
+            formatted = render.format_local(
+                "2026-06-30T23:30:00+00:00", render.LOCAL_DATE_TIME_FORMAT
+            )
+        assert formatted == "Jul 01 01:30"
+
+    def test_missing_and_unparseable_are_blank(self):
+        assert render.format_local(None) == ""
+        assert render.format_local("") == ""
+        assert render.format_local("not-a-date") == ""
+
+
 class TestStreamRow:
-    def test_formats_time_kind_and_message(self):
-        row = render.stream_row(
-            _Event(timestamp="2026-06-26T14:02:31.123456+00:00", kind="assistant_text", message="hi")
-        )
-        assert row.time == "14:02:31"
+    def test_formats_time_kind_and_message(self, local_timezone):
+        with local_timezone("Europe/Warsaw"):  # UTC+2 in June
+            row = render.stream_row(
+                _Event(
+                    timestamp="2026-06-26T14:02:31.123456+00:00",
+                    kind="assistant_text",
+                    message="hi",
+                )
+            )
+        assert row.time == "16:02:31"
         assert row.kind == "assistant_text"
         assert row.message == "hi"
         assert row.label == ""
@@ -397,12 +430,13 @@ def _event(ws="ws-01-1", kind="agent_crash", message="connection lost", phase=12
 
 
 class TestAgentErrorEventRows:
-    def test_parses_events_into_rows(self):
+    def test_parses_events_into_rows(self, local_timezone):
         payload = {"agent_error_events": [_event()]}
-        rows = render.agent_error_event_rows(payload)
+        with local_timezone("Europe/Warsaw"):  # UTC+2 in July
+            rows = render.agent_error_event_rows(payload)
         assert len(rows) == 1
         row = rows[0]
-        assert row.time == "18:28:40"
+        assert row.time == "20:28:40"
         assert row.workspace_id == "ws-01-1"
         assert row.phase_label == "phase 12"
         assert row.kind == "agent_crash"

mcp_server/tui/app.py

@@ -30,7 +30,6 @@
 import json
 import shutil
 import sys
-from datetime import datetime, timezone
 from pathlib import Path
 from typing import Any
 
@@ -942,15 +941,11 @@ def _session_label(s: dict) -> str:
         checkpoint_key,
     )
 
-    # Date from ISO created_at ("2026-06-30T14:23:45+00:00" → "Jun 30 14:23")
+    # Local-time date from ISO created_at ("2026-06-30T14:23:45+00:00" → "Jun 30 16:23" in CEST)
     created_at_raw = s.get("created_at", "")
-    date_str = ""
-    if created_at_raw:
-        try:
-            dt = datetime.fromisoformat(created_at_raw).astimezone(timezone.utc)
-            date_str = dt.strftime("%b %d %H:%M")
-        except ValueError:
-            date_str = created_at_raw[:16]
+    date_str = render.format_local(created_at_raw, render.LOCAL_DATE_TIME_FORMAT)
+    if created_at_raw and not date_str:
+        date_str = created_at_raw[:16]
 
     # Cancellations are always user-initiated; spell that out in the list.
     status_word = "CANCELLED BY USER" if status_key == "cancelled" else status_key.upper()

mcp_server/tui/render.py

@@ -12,7 +12,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
-from datetime import datetime
+from datetime import datetime, timezone
 from typing import Any
 
 from tui.constants import (
@@ -323,14 +323,21 @@ class StreamRow:
     message: str
 
 
-def _hhmmss(timestamp: str | None) -> str:
-    """Format an ISO timestamp as HH:MM:SS; "" when missing/unparseable."""
+LOCAL_TIME_FORMAT = "%H:%M:%S"
+LOCAL_DATE_TIME_FORMAT = "%b %d %H:%M"
+
+
+def format_local(timestamp: str | None, fmt: str = LOCAL_TIME_FORMAT) -> str:
+    """Format a backend ISO timestamp (UTC, naive or aware) in local time; "" when unusable."""
     if not timestamp:
         return ""
     try:
-        return datetime.fromisoformat(timestamp).strftime("%H:%M:%S")
+        parsed = datetime.fromisoformat(timestamp)
     except ValueError:
         return ""
+    if parsed.tzinfo is None:
+        parsed = parsed.replace(tzinfo=timezone.utc)
+    return parsed.astimezone().strftime(fmt)
 
 
 def stream_row(event: Any) -> StreamRow:
@@ -341,7 +348,7 @@ def stream_row(event: Any) -> StreamRow:
     """
     label = getattr(event, "subagent_name", None) or getattr(event, "tool_name", None) or ""
     return StreamRow(
-        time=_hhmmss(getattr(event, "timestamp", None)),
+        time=format_local(getattr(event, "timestamp", None)),
         kind=str(getattr(event, "kind", None) or "unknown"),
         label=str(label),
         message=str(getattr(event, "message", None) or ""),
@@ -487,7 +494,7 @@ def agent_error_event_rows(payload: dict[str, Any] | None) -> list[AgentErrorEve
         phase = event.get("phase")
         rows.append(
             AgentErrorEventRow(
-                time=_hhmmss(event.get("at")),
+                time=format_local(event.get("at")),
                 workspace_id=str(event.get("workspace_id") or ""),
                 phase_label=f"phase {phase}" if phase is not None else "",
                 kind=str(event.get("kind") or ""),