Custom Endpoint BYOK models disappear after upgrading to VS Code 1.132 unless chat.agentHost.byokModels.enabled is manually enabled

[Hakkinex]

Type: Bug

Environment

OS: Windows 11
VS Code: 1.132
GitHub Copilot enabled
Custom model configured through Chat: Manage Language Models → Custom Endpoint

Issue

After upgrading to VS Code 1.132, my existing Custom Endpoint / BYOK model no longer appears in Manage Language Models / the model picker.

The same chatLanguageModels.json configuration worked correctly in the previous VS Code version.

Example configuration:

[
{
"name": "Metapi",
"vendor": "customendpoint",
"apiKey": "${input:chat.lm.secret.7529fe01}",
"apiType": "chat-completions",
"models": [
{
"id": "claude-sonnet-5",
"name": "Claude Sonnet 5",
"url": "http://100.x.x.x:4000/v1/chat/completions",
"toolCalling": true,
"vision": false,
"maxInputTokens": 112000,
"maxOutputTokens": 16000
}
]
}
]

In VS Code 1.132, searching Settings for BYOK does not show any setting for Agent Host BYOK models.

However, manually adding the following to settings.json:

"chat.agentHost.byokModels.enabled": true

immediately restores the Custom Endpoint model.

Steps to reproduce

Configure a Custom Endpoint BYOK model.
Verify that the model is visible and usable in the previous VS Code version.
Upgrade to VS Code 1.132.
Open Chat: Manage Language Models or the chat model picker.
Observe that the existing Custom Endpoint model is missing.
Search Settings for BYOK; no Agent Host BYOK toggle is exposed.
Manually add:
"chat.agentHost.byokModels.enabled": true
Restart/reload VS Code.
The Custom Endpoint model becomes available again.

Expected behavior

Existing Custom Endpoint / BYOK models should continue to work after upgrading, or VS Code should automatically migrate/enable the required Agent Host BYOK bridge.

If manual opt-in is required, the corresponding setting should be exposed in the Settings UI and users should receive a clear indication explaining why their previously configured models are unavailable.

Actual behavior

Existing BYOK models silently disappear after upgrading to 1.132. The required setting is not visible in the Settings UI, so there is no obvious way for users to recover their models without knowing the undocumented/manual setting.

Workaround

"chat.agentHost.byokModels.enabled": true

This restores the models.

VS Code version: Code 1.132.0 (df53daa, 2026-08-04T15:30:20Z)
OS version: Windows_NT x64 10.0.26200
Modes:

System Info

Item	Value
CPUs	Intel(R) Core(TM) Ultra 7 155H (22 x 2995)
GPU Status	2d_canvas: enabled GPU0: VENDOR= 0x8086, DEVICE=0x7d55 [Intel(R) Arc(TM) Graphics], DRIVER_VENDOR=Intel, DRIVER_VERSION=32.0.101.5768 ACTIVE GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.8875 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 webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	31.36GB (13.65GB free)
Process Argv	--crash-reporter-id 5ecf8c2e-fdb3-4c5f-8a56-43a73fa17183 --crash-reporter-id 5ecf8c2e-fdb3-4c5f-8a56-43a73fa17183
Screen Reader	no
VM	0%

Extensions (18)

Name	Identifier	Author	Version
markdownlint	davidanson.vscode-markdownlint	DavidAnson	0.62.1
GitHub Repositories	github.remotehub	GitHub	0.64.0
GitHub Pull Requests	github.vscode-pull-request-github	GitHub	0.162.0
Markdown Image	hancel.markdown-image	hancel	1.1.51
Python Debugger	ms-python.debugpy	ms-python	2026.6.0
Python	ms-python.python	ms-python	2026.4.0
Pylance	ms-python.vscode-pylance	ms-python	2026.3.1
Python Environments	ms-python.vscode-python-envs	ms-python	1.36.0
Jupyter	ms-toolsai.jupyter	ms-toolsai	2025.9.1
Jupyter Keymap	ms-toolsai.jupyter-keymap	ms-toolsai	1.1.2
Jupyter Notebook Renderers	ms-toolsai.jupyter-renderers	ms-toolsai	1.3.0
Jupyter Cell Tags	ms-toolsai.vscode-jupyter-cell-tags	ms-toolsai	0.1.9
Jupyter Slide Show	ms-toolsai.vscode-jupyter-slideshow	ms-toolsai	0.1.6
Remote Repositories	ms-vscode.remote-repositories	ms-vscode	0.42.0
Note Collection	sarakale.note-collection	SaraKale	1.0.8
Markdown Preview Enhanced	shd101wyy.markdown-preview-enhanced	shd101wyy	0.8.30
Markdown PDF	yzane.markdown-pdf	yzane	2.2.0
Markdown All in One	yzhang.markdown-all-in-one	yzhang	3.6.3

A/B Experiments

vsliv368cf:30146710
pythonvspyt551cf:31249601
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
envsactivate1:31551504
gh487529:31544284
cloudbuttont:31379625
42190218_ostrepl:31403339
bj468946:31457056
ddidtcf:31399634
ec5jj548:31422691
cp_cls_t_966_ss:31526232
4je02754:31466945
8hhj4413:31478653
cp_cls_c_1081:31454833
conptydll_true:31498968
e9c30283:31461165
test_treatment2:31471001
46204921:31447328
idci7584:31464702
e3e4d672:31494082
ei9d7968:31496641
nes-extended-on:31455476
chat:31457767
8hig5102:31480529
89g7j272:31518289
7e187181:31503455
i2gc6536:31499202
52612955:31516516
ghj88844:31499326
h08i8180:31475369
ddid_t:31478206
hmra_i5g22:31518061
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
db5d2638:31499441
jb_cp_cls_t_632:31543129
56dj4588:31512888
32d76977:31512328
ha629193:31508444
cdk-lw-on:31524445
f9bf7985:31543584
jh5f2457_c:31540921
jbcp_cls_pctr_t:31531130
61138546:31518536
cp_intellij_t_nes:31548657
d7b18187:31526828
nes-curr-leftover-1500:31538366
ahp-both-windows:31556933
h561g132:31533256
sessions_5:31532894
ihg5j128:31534457
f412h606:31551416
9gg7f176:31542112
max-result-50:31551153
nes-ex-cf-euporie-03:31542868
5fe6f778:31554331
allow-none:31555437
fd5dc207:31551400
c7c27ce7:31554789
nes-gb3-nf-6k:31554346
8hc4g144:31558143
0dg73464:31554319
treatment-23-1:31555779
unuse_dynamic_mcp:31555281
0d8dfbc3:31560381
nemo-v2:31561728
session-mark-done:31558131