feat(tui): show timestamps on assistant messages - #43246

The following comment was made by an LLM, it may be inaccurate:

I found related PRs that may be worth reviewing:

Related PRs:

1. feat(tui): show per-part timestamps for thinking and tool blocks #42499 - feat(tui): show per-part timestamps for thinking and tool blocks

   • This PR adds timestamps to thinking and tool blocks, which is closely related to the timestamp feature in PR feat(tui): show timestamps on assistant messages #43246. It may have overlapping logic for displaying timestamps in the TUI.

2. feat(tui): show assistant turn completion time #37929 - feat(tui): show assistant turn completion time

   • This PR shows assistant turn completion time, which is related to displaying time-based information on assistant messages in the TUI.

These PRs are working on similar timestamp/time-display features in the TUI and may have relevant code patterns or logic that could affect the current PR.

Thanks for the pointers. I reviewed both PRs:

• feat(tui): show per-part timestamps for thinking and tool blocks #42499 adds per-part timestamps (thinking headers, inline tools, block tools) using each part's start time. It is gated by the existing showTimestamps toggle, same as this PR. No overlap — different render targets.
• feat(tui): show assistant turn completion time #37929 appends the turn completion time to the summary line (e.g. the line at the bottom of an assistant turn). It is always visible (not gated by showTimestamps). This PR adds the message creation timestamp to the AssistantMessage footer, gated by showTimestamps. There is a potential merge conflict since both touch the same Show block near the duration line in session/index.tsx, but the features are complementary: feat(tui): show assistant turn completion time #37929 shows when the turn finished, this PR shows when the message was created.

No duplication — all three cover different timestamp surfaces.

AI code review — automated review for reference; please use your judgment.

• packages/tui/test/util/timestamps.test.ts:1 — the test imports todayTimeOrDateTime, time, and datetime from src/util/locale, but this diff never touches that file. If those exports don't already exist, both the tests and the new <Show> block will fail to compile — please confirm they're pre-existing (or add them here).
• packages/tui/src/routes/session/index.tsx:1568 — same for ctx.showTimestamps(): no change here wires up that flag. If it's new, its definition/config plumbing seems missing from this PR.
• packages/tui/test/util/timestamps.test.ts:15 — asserting toContain("·") couples the test to the exact separator glyph used by datetime; prefer asserting on digits/date pattern so formatting tweaks don't break tests.
• packages/tui/test/util/timestamps.test.ts:8 — todayTimeOrDateTime(now) near midnight could race between "today" and "yesterday" in CI; consider injecting a fixed clock or tolerating both outputs.

Thanks for the review. All points addressed:

1. todayTimeOrDateTime, time, datetime exports — these are pre-existing in packages/tui/src/util/locale.ts (lines 5, 10, 17). No changes needed.
2. ctx.showTimestamps() wiring — pre-existing in packages/tui/src/routes/session/index.tsx:278 as createMemo(() => timestamps() === 'show'), exposed via context at line 163. No changes needed.
3. Test asserting on separator glyph — replaced toContain('·') with toMatch on digit patterns so formatting tweaks don't break tests.
4. Midnight race in CI — replaced Date.now() with a fixed date using setHours(14, 30, 0, 0) to avoid the today/yesterday boundary.

Any updates on this? I need this info to see whether the session KV cache is still alive or not 😅

This branch has been upgraded to V2. We're no longer taking PRs for V1. If you think this is still relevant, please port it over and open it for V2.

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