Performance: slash command menu lags on first 1–3 chars with many commands/skills

Support Bug Reports
, ,
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

When you have a large number of slash commands / skills, typing the first 1–3 characters after / causes noticeable UI lag / jank.

Likely cause: single-char (and similarly two-char) prefix search returns a huge match set and filters/renders on every keystroke. Past a certain command count — or a per-machine performance gate — this becomes painful.

Related but distinct from Slash command switching Skill lag (that thread is about lag when navigating the skill list / full previews). This report is about lag while typing short prefixes with many commands registered.

Steps to Reproduce

  1. Install / enable a large set of skills + custom slash commands (e.g. 50–150+ across ~/.cursor/skills, project skills, commands).
  2. Open Agent/Chat input.
  3. Type / then quickly type the first 1–2 characters of a command name (e.g. /g, /gs).
  4. Observe input lag / stalled keystrokes / sluggish picker updates for those first characters.
  5. Continue typing to 3+ more distinctive characters — lag typically drops as the match set shrinks.

Expected Behavior

Slash command filtering should stay responsive even with large command catalogs.

Suggested mitigation (product fix):

  • Debounce short-prefix filtering: e.g. ~50ms delay with no further keystrokes before running the filter for the first 2–3 characters after /.
  • Optionally: skip or throttle expensive match/render work until query length ≥ N, or until command count exceeds a threshold / per-machine performance gate.
  • Cap or virtualize the result list for very broad prefixes so 1–2 char queries don’t force rendering hundreds of matches every keystroke.

Operating System

MacOS

Version Information

Cursor 3.13.25 (arm64)
Commit: 31e8d61c448c7472e371505838a0fe34083dad50
OS: macOS 14.3 (Darwin 23.3.0, arm64)

Additional Information

  • Repro environment has ~95 user skills under ~/.cursor/skills plus many more agent/project skills — enough that 1–2 char prefixes match a large fraction of the catalog.
  • Lag is concentrated on the first few characters; longer prefixes feel fine once matches narrow.
  • This is a UX/perf issue that scales with command count; a fixed debounce for short queries would likely fix it without hurting discoverability for small catalogs.

Does this stop you from using Cursor

No - Cursor works, but with this issue

6

Hey there!

What you’re describing isn’t intended behavior, and it’s not caused by anything in your setup. The classic composer’s slash menu isn’t optimized for large skill/command catalogs, so filtering the first few characters can stall the renderer while it re-renders the full list. We’ve let the team know and this is an issue we’re tracking.

A couple of things that may help in the meantime:

  1. Temporarily disabling skills/commands you don’t reach for often will meaningfully reduce the per-keystroke work.
  2. If you use the Agents Window (Cmd/Ctrl+Shift+N), its slash menu uses a windowed renderer and stays responsive with a large catalog - worth trying to see if it works for your flow.

No timeline to share yet, but I’ll post here when there’s an update.