Built-in AI features: agent-host process (Code Helper) causes sustained ~180% CPU and unbounded memory growth on macOS

Type: Bug ### Summary When the built-in AI features are enabled (`chat.disableAIFeatures: false`), a `Code Helper` process (agent-host) immediately starts using ~180–200% CPU and its memory footprint grows continuously without ever stabilizing. Setting `chat.disableAIFeatures: true` stops the growth instantly; re-enabling it brings the problem back right away. The GitHub Copilot / Copilot Chat extensions are **not** installed — this comes from the AI features built into VS Code itself. ### Observed behavior - `Code Helper` (agent-host) jumps from ~0% to ~180% CPU within seconds of enabling AI features (see attached screenshot, PID 33728: 180.9% CPU, memory already climbing). - Memory footprint grows linearly, roughly **4 GB → 7 GB in about one hour**, with no plateau. - CPU stays at ~190–200% the whole time, even while the editor is idle. - CPU die temperature reaches 97–104 °C. - A separate `copilot-runtime` process is also running, but stays low (~2% CPU, ~60 MB). **1. Right after enabling AI features:** CPU jumps to ~180% immediately. **2. After ~30 minutes with AI features enabled:** memory footprint keeps growing linearly. ### Steps to reproduce 1. Open any folder/workspace on macOS (Apple Silicon). 2. Make sure `chat.disableAIFeatures` is `false`. 3. Open a file and start editing normally. 4. Watch the `Code Helper` process in Activity Monitor: CPU goes to ~180% and memory keeps growing. 5. Set `chat.disableAIFeatures` to `true` → growth stops immediately. ### What I already tried - Updated VS Code to the latest version — still reproducible. - Reproduced in different projects, from a small one (~150 files) to a large one, so it doesn't seem related to workspace size. - Added a large vendor framework folder to `files.watcherExclude` — no change. - Ruled out my other extensions (GitLens, Git Graph, ES7+ React snippets, Claude Code for VS Code); the issue follows only the `chat.disableAIFeatures` setting. ### Expected behavior The agent-host process should settle to low CPU usage when idle and keep a bounded memory footprint. ### Workaround I currently toggle `chat.disableAIFeatures` on and off with a keybinding, enabling AI features only when I need inline suggestions, and reload the window when memory gets too high. VS Code version: Code 1.143.0 (Universal) (2d0b7506a36c1d6db9a466440131a8e01eab2289, 2026-10-20T14:31:47-07:00) OS version: Darwin arm64 27.0.0 Modes: System Info |Item|Value| |---|---| |CPUs|Apple M3 Pro (11 x 2400)| |GPU Status|2d_canvas: enabled GPU0: VENDOR= 0x106b [Google Inc. (Apple)], DEVICE=0x0000 [ANGLE (Apple, ANGLE Metal Renderer: Apple M3 Pro, Version 27.0.1 (Build 26A434))], DRIVER_VENDOR=Apple, DRIVER_VERSION=27.0.1 *ACTIVE* Machine model name: Mac Machine model version: 15.6 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: enabled_on trees_in_viz: disabled_off video_decode: enabled video_encode: enabled webgl: enabled webgpu: enabled webnn: disabled_off| |Load (avg)|7, 6, 6| |Memory (System)|18.00GB (0.11GB free)| |Process Argv|--crash-reporter-id 5d811f52-9eca-4198-897e-0893907bc0d3| |Screen Reader|no| |VM|0%| Extensions (17) Name|Identifier|Author|Version ---|---|---|--- Claude Code for VS Code|anthropic.claude-code|Anthropic|2.1.306 Turbo Console Log|chakrounanas.turbo-console-log|ChakrounAnas|3.29.0 ESLint|dbaeumer.vscode-eslint|dbaeumer|3.0.34 ES7+ React/Redux/React-Native snippets|dsznajder.es7-react-js-snippets|dsznajder|4.4.3 GitLens — Git supercharged|eamodio.gitlens|eamodio|19.4.0 VSCode Great Icons|emmanuelbeziat.vscode-great-icons|emmanuelbeziat|2.1.121 Auto Rename Tag|formulahendry.auto-rename-tag|formulahendry|0.1.10 GitHub Actions|github.vscode-github-actions|github|0.32.3 AI Toggle Status|maicol.ai-toggle-status|maicol|1.0.1 Git Graph|mhutchie.git-graph|mhutchie|1.30.0 Portuguese (Brazil) Language Pack for Visual Studio Code|ms-ceintl.vscode-language-pack-pt-br|MS-CEINTL|1.131.2026090407 Material Icon Theme|pkief.material-icon-theme|PKief|5.39.0 Live Server|ritwickdey.liveserver|ritwickdey|5.7.10 open in browser|techer.open-in-browser|techer|3.1.0 Highlight Matching Tag|vincaslt.highlight-matching-tag|vincaslt|0.11.0 JS-Beautify for VS Code|vsce-toolroom.vscode-beautify|vsce-toolroom|1.6.0 TODO Highlight|wayou.vscode-todo-highlight|wayou|1.0.5 A/B Experiments ``` vsliv368:30146709 binariesv615:30325510 nativeloc1:31344060 dwcopilot:31170013 dwoutputs:31242946 copilot_t_ci:31333650 e5gg6876:31282496 pythonrdcb7:31342333 6518g693:31463988 aj953862:31281341 envsactivate1:31551504 cloudbuttont:31379625 3efgi100_wstrepl:31403338 ec5jj548:31422691 cp_cls_t_966_ss:31526232 4je02754:31572277 c3h7c220:31478652 ge8j1254_inline_auto_hint_haiku:31490510 cp_cls_t_1081:31454832 conptydll_true:31498968 e9c30283:31461165 c9b86496:31447327 ei9d7968:31496641 chat:31457767 8hig5102:31480529 ah:31461780 89g7j272:31518289 2d1bi976:31596492 i2gc6536:31499202 52612955:31516516 ddid_c:31478207 hmra_i5g22:31518061 7df3h592:31512476 cp_cls_t_1082:31535311 608b4df9:31595861 logging_enabled_new:31498466 db5d2638:31499441 jb_cp_cls_t_632:31543129 748c7209:31512887 32d76977:31512328 ha629193:31508444 jh5f2457_c:31540921 jbcp_cls_pctr_t:31531130 cp_intellij_t_nes:31548657 ahp-both-windows:31556933 ihg5j128:31534457 9gg7f176:31542112 sandbox-ui-on-2:31543161 enable_editor_pane_layout:31569726 allow-none:31555437 ac562147:31564510 1h923230:31564177 treatment-23-1:31555779 unuse_dynamic_mcp:31555281 0d8dfbc3:31570291 a1hcc538:31559322 0c1h4866:31566224 session-mark-done:31591648 multi-root:31593626 5b8j3302:31564601 autotiers:31584978 mangle-name-treatment:31572634 atk_rai_validation_enable:31598258 allow-signed-out:31592042 b17abb00-cfec-4134-90da-ee5e32ce4426:31602001 intellij_nes_preview_t:31580086 39a5d156:31574986 links-treatment:31596176 aw-autom-on:31583758 issue9151-7215f35b:31597540 usage_tips_endabled_0911:31587631 7g328426_fixed:31595622 codex-agent-host-stable-editor:31599810 54hd3363:31600021 skill-budget-30000:31597277 sessioninlinediffenabled_disabled:31587634 welcomesignin9359t:31602106 e6882f69-f5cc-4f90-9073-69a4ca3e50ea:31602109 d6a5dc66-a24d-4215-bf31-317b28ac768a:31603712 0915b77b-4632-4fb2-9377-b5640c1e9623:31601711 5a177259:31599157 i67i8290:31599156 edbgf432:31599155 msft-auth-on:31593345 variation8-original-feedback:31600301 permission_prompt_control:1332567 ccr_pr_nudge_auto_review:1319472 vsc_wsm_t:1340632 cfee5631:1379228 jc553158:1433349 hdfaf120:1463096 cmc_aa_t:1435711 plus-and-new:1462601 t_ws_f7ce1948:1455090 h56ae855:1460391 seatcta-d9cadb09:1462477 ```