Architecture and hard-won debugging lessons for customization enablement (plugins, MCP servers, agents, skills, instructions) in the agent host. Use when changing how customizations are discovered, published, enabled/disabled, or handed to a provider SDK; when a customization shows the wrong enabled state in the UI; or when a disabled MCP server or plugin is still reaching the model.
Install
npx skills add microsoft/vscode --skill customizations-in-the-agent-hostnpx skills add microsoft/vscode --skill customizations-in-the-agent-host -a claude-code -gnpx skills add microsoft/vscode --skill customizations-in-the-agent-host -a codex -ggemini skills install https://github.com/microsoft/vscode.git --path .github/skills/customizations-in-the-agent-hostgh skill install microsoft/vscode customizations-in-the-agent-hostgit clone --depth 1 https://github.com/microsoft/vscode /tmp/microsoft__vscode
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/microsoft__vscode/.github/skills/customizations-in-the-agent-host ~/.claude/skills/customizations-in-the-agent-host # Claude Code
cp -R /tmp/microsoft__vscode/.github/skills/customizations-in-the-agent-host ~/.agents/skills/customizations-in-the-agent-host # Codex, Cursor, Gemini CLI, Copilot, OpenCode