@ context menu does not trigger when the prompt contains Chinese text

[xxxxsk]

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 @ context menu does not trigger when the prompt contains Chinese text.

Typing @ in an English-only prompt opens the context menu normally, allowing me to attach files or other context. However, when the prompt already contains Chinese characters, typing @ does not open the menu.

To reproduce

1. Open Warp and switch to the AI input.
2. Type Chinese text followed by a space, for example: 你好 @
3. Observe that the @ context menu does not appear.
4. Clear the input and type an English prompt followed by @, for example: hello @
5. Observe that the @ context menu appears normally.

Expected behavior

Typing @ should open the same context menu regardless of whether the prompt contains English, Chinese, or other UTF-8 characters.

Screenshots, videos, and logs

No response

Operating system (OS)

macOS

Operating system and version

26.5.1

Shell Version

zsh 5.9

Current Warp version

v0.2026.07.29.09.05.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?

No

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

No response

[oz-for-oss]

@xxxxsk

Here's what I found while triaging this issue:

Thanks for the clear repro. This matches a client-side Unicode handling bug in the @ context-menu trigger path, so no additional reporter details are needed right now.

I've flagged this for the factory auto-implement queue.

Maintainer details

I concluded that typing @ after Chinese text in the AI input likely fails because the @ context-menu trigger checks byte-offset cursor positions as character indices..

Triage summary

This looks like a client-side bug in the AI input's @ context menu trigger. The reporter's repro is specific and consistent: hello @ opens the menu, while 你好 @ does not.

Reproducibility

High. The issue has a minimal repro on macOS stable, and the relevant trigger code appears to mishandle UTF-8 text before the @ symbol.

Likely root cause

app/src/terminal/input.rs reads the editor cursor as a byte offset via start_byte_index_of_last_selection, then checks the previous characters with buffer_text.chars().nth(cursor_position.saturating_sub(1)) and nth(cursor_position.saturating_sub(2)) in should_enable_ai_context. For ASCII prompts, byte offsets and character indices line up; for Chinese characters before @, they do not, so the code fails to detect the just-typed @. Related AI context menu search/update paths also store at_symbol_position as byte offsets, so a fix should keep byte offsets and char iteration conversions consistent.

Duplicate check

I checked all open non-PR issues with pagination. The closest CJK/IME/Unicode issues cover different surfaces (CJK rendering, IME focus, double-click selection, or fuzzy matcher behavior), so I did not identify a likely duplicate.

Implementation notes

A narrow fix should normalize the @ trigger and query extraction logic to use byte-offset-safe string slicing or explicit byte-to-char conversion, and add regression coverage for a prompt like 你好 @ opening the AI context menu.

This is my automated analysis and may be incorrect. A maintainer will verify the details.

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