TS IntelliSense is very slow or loads endlessly on simple ArkType wrapper

Type: Performance Issue

- use fresh vanilla / portable VSCode 1.114.0 (no extensions, and i have no custom settings other than TS Server Verbose logging, as shown at the end of the second video)
- clone https://github.com/FunctionDJ/vscode-arktype-issue **(includes full tsserver.log from second video!)**
- npm install
- see how IntelliSense behaves, e.g. when adding a TS syntax error and using hover (see videos)

I'm aware that this could be an issue with circular types, but then VSCode or tsserver should probably terminate the IntelliSense processing sooner and show an error or something.

### Loading IntelliSense status hangs forever when opening the file after launching VSCode:

https://github.com/user-attachments/assets/60b4e11b-56ac-4511-bb75-5591de7d7041

### Adding a syntax error takes extremely long to be recognized and hover never resolves:

https://github.com/user-attachments/assets/0a46011d-93ad-4714-8581-882eb799f934

VS Code version: Code 1.114.0 (e7fb5e96c0730b9deb70b33781f98e2f35975036, 2026-04-01T09:27:11Z)
OS version: Windows_NT x64 10.0.26200
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|13th Gen Intel(R) Core(TM) i7-13700H (20 x 2918)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x10de, DEVICE=0x25ac [NVIDIA GeForce RTX 3050 6GB Laptop GPU], DRIVER_VENDOR=NVIDIA, DRIVER_VERSION=32.0.15.9597 *ACTIVE*
GPU1: VENDOR= 0x8086, DEVICE=0xa7a0 [Intel(R) Iris(R) Xe Graphics], DRIVER_VERSION=31.0.101.4575
GPU2: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.7309
Machine model name:
Machine model version:
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: enabled
multiple_raster_threads: enabled_on
opengl: enabled_on
rasterization: enabled
raw_draw: disabled_off_ok
skia_graphite: disabled_off
trees_in_viz: disabled_off
video_decode: enabled
video_encode: enabled
webgl: enabled
webgl2: enabled
webgpu: enabled
webnn: disabled_off|
|Load (avg)|undefined|
|Memory (System)|15.69GB (4.07GB free)|
|Process Argv|--crash-reporter-id aa49ccd1-a2fe-472e-b2a5-d91f270dd974|
|Screen Reader|no|
|VM|0%|

Process Info

```
CPU % Mem MB PID Process
0 137 1564 code
0 196 2180 extension-host [1]
0 103 16956 C:\Users\Function\Desktop\vscode-portable\Code.exe c:\Users\Function\Desktop\vscode-portable\e7fb5e96c0\resources\app\extensions\json-language-features\server\dist\node\jsonServerMain --node-ipc --clientProcessId=2180
0 235 22560 electron-nodejs (tsserver.js)
0 115 16848 electron-nodejs (typingsInstaller.js)
0 173 23300 electron-nodejs (tsserver.js)
0 123 4092 pty-host
0 8 16792 conpty-agent
0 103 24312 "C:\Program Files\PowerShell\7\pwsh.exe" -noexit -command "try { . \"c:\Users\Function\Desktop\vscode-portable\e7fb5e96c0\resources\app\out\vs\workbench\contrib\terminal\common\scripts\shellIntegration.ps1\" } catch {}"
1 381 5996 window [1] (main.ts - testtemp - Visual Studio Code)
0 32 16836 crashpad-handler
0 153 21628 shared-process
0 112 21644 file-watcher [1]
0 183 23900 gpu-process
0 47 24360 utility-network-service
```

Workspace Info

```
| Window (main.ts - testtemp - Visual Studio Code)
| Folder (testtemp): 8 files
| File types: json(3) gitignore(1) ts(1) log(1)
| Conf files: package.json(1) tsconfig.json(1);
```

Extensions: none
A/B Experiments

```
vsliv368cf:30146710
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
6abeh943:31336334
envsactivate1:31464700
cloudbuttont:31379625
aihoversummaries_f:31469309
42190218_ostrepl:31403339
use-responses-api:31390855
ec5jj548:31422691
cp_cls_c_966_ss:31454199
4je02754:31466945
8hhj4413:31478653
cp_cls_c_1081:31454833
core-renderer-profiling-on:31440367
e9c30283:31461165
test_treatment2:31471001
idci7584:31464702
showingstats:31481873
i54ji102:31458073
534a6447:31478749
chat:31457767
t-some:31486549
cpptoolson-v2:31475363
regularsignin:31487065
db0gd219:31481871
ec1eg703:31488002
ddid_c:31478207

```

Clone the linked vscode-arktype-issue reproduction, run npm install, and reproduce the IntelliSense delays in VS Code 1.114.0. Inspect main.ts, package.json, tsconfig.json, and the included tsserver.log first; compare behavior with and without the reported type pattern. Done means isolating a minimal reproducible case and establishing the affected TypeScript language-service behavior.

Written by the indexing model from the issue text.