Japanese IME conversion candidates popup is misaligned from cursor/input line

[tonkotsuboy]

Pre-submit Checks

• I have searched Warp bugs and there are no duplicates
• I have searched Warp known issues page and my issue is not there
• I have an issue with AI and have included the debugging ID (Optional, but helps expedite the AI quality fix). Debugging ID instructions
• I have technical issue and have included the logs (optional, but helps expedite the bug fix). Log instructions

Describe the bug

The Japanese IME conversion candidates popup (the window showing kanji/hiragana suggestions) appears shifted/misaligned from the cursor and input line in Warp.

Otherwise Warp has been great — looking forward to improvements!

To reproduce

1. Open Warp on macOS
2. Switch to a Japanese IME
3. Start typing Japanese characters at the prompt (hiragana input that triggers kanji conversion)
4. Observe the IME conversion candidates popup — it appears shifted/misaligned from the actual cursor position and input line

Expected behavior

The IME conversion candidates popup should appear directly at the cursor position, aligned with the input line — the same behavior as other macOS applications.

Screenshots, videos, and logs

Screenshots are attached below. The red arrow points to the IME conversion candidates popup ("ここには日本語を入力しています / Tab キーで選択") — in Warp it appears far above the actual cursor position, separated from the input line. The second screenshot shows the same Japanese IME input in cmux where the popup is positioned correctly, directly under the cursor.

Confirmed this issue does NOT reproduce in other terminals (e.g. cmux). Only observed in Warp.

Original report on X (also includes the first screenshot):
https://x.com/tonkotsuboy_com/status/2046383630839377977

Operating system (OS)

macOS

Operating system and version

macOS 26.4

Shell Version

No response

Current Warp version

v0.2026.04.15.08.45.stable_02

Regression

No, this bug or issue has existed throughout my experience using Warp

Recent working Warp date

No response

Additional context

No response

Does this block you from using Warp daily?

Yes, this issue prevents me from using Warp daily.

Is this an issue only in Warp?

Yes, I confirmed that this only happens in Warp, not other terminals.

Warp Internal (ignore): linear-label:b9d78064-c89e-4973-b153-5178a31ee54e

None

[acarl005]

Hi @tonkotsuboy thanks for taking the time to report the issue and also your kind words. Can you tell me if this misalignment occurs only in a claude code session? If you type other commands outside of claude code how is the IME?

[tonkotsuboy]

Hi @acarl005, thanks for the quick reply!

You're right — the misalignment only occurs inside TUI-based AI coding sessions such as Claude Code and Gemini CLI. When I type Japanese directly at the regular Warp prompt (outside of those sessions), the IME conversion candidates popup is correctly aligned with the cursor, just like in other macOS apps.

Here is a comparison:

✅ Regular Warp prompt (works correctly):

❌ Inside a Claude Code session (misaligned):

❌ Inside a Gemini CLI session (misaligned):

So the issue seems specific to how Warp positions the IME popup while these TUI applications are running in the foreground. Hope this helps narrow it down!

[maxmilian]

Likely related: I just filed #9709 with a reproducible test case for 超注音 (Yahoo Bopomofo, a third-party Traditional Chinese IME), where right/left arrow advances candidate selection by 2 instead of 1 — reproducing at the regular Warp prompt (not only inside TUI apps).

Different surface symptom from this issue (event double-counting vs. candidate popup positioning), but the suspected root cause — keyDownImpl in crates/warpui/src/platform/mac/objc/host_view.m dispatching keyDown events through two parallel paths (interpretKeyEvents: + warp_handle_view_event) during IME composition — could plausibly explain both. Linking here in case it helps maintainers consolidate.