S258 Handoff

Documentation for Sessions

S258 Handoff — Chat Plugin Core & Native VSCode Chat

Session: 258 Date: 2026-03-23 Status: Implementation Complete — Backend endpoint pending Branch: session-254-258 (shared, no commits made)

What Was Delivered

1. `@libs-ai/chat-plugin-core` — New NX Library

Path: libs/libs-ai/chat-plugin-core/ Files: 29 TypeScript, 0 Angular imports Tag: scope:ai, type:core

Structure:

src/lib/
├── types/           # ReactiveValue, ComponentRef, PluginCategory, PlatformCapability, ChatMessage, etc.
├── interfaces/      # ChatPlugin interface, provider interfaces, resolution logic
├── plugins/
│   ├── context/     # rich-context, capabilities, suggestions
│   ├── intelligence/# model, agent, mastery, learning
│   ├── generation/  # generation, module-builder, teach, prompt-library
│   ├── bridge/      # computer-use-bridge, observatory, awareness
│   └── input/       # voice, action, context-legacy
├── composition/     # createStandardPluginSet() — platform-aware preset factory
└── utils/           # isChatPlugin(), getPluginCategory(), hasCapability()

2. `@libs-ai/vitto-chat` — Angular Adapter

Modified files (3 remain in plugins/):

index.ts — re-exports all 17 factories from chat-plugin-core
chat-plugin.interface.ts — re-exports ChatPlugin type
plugin-presets.ts — Angular adapter wrapping PluginPresetConfig → StandardPluginSetConfig

Deleted: 17 old plugin .ts files (dead code after migration)

3. VSCode Extension v0.13.0

New files:

services/ide-tool.service.ts — 7 VSCode API tools
services/agent-session.service.ts — SSE streaming + tool execution loop
services/context-provider.service.ts — IDE context gathering
panels/webview/components/agent/agent-chat-view.ts — Lit chat component
panels/webview/components/agent/agent-message.ts — Message renderer
panels/webview/components/agent/plugin-bridge.ts — Plugin import bridge

Modified:

main-panel.ts — Chat tab shell + agent message handlers
types.ts — 13 new message types + IdeContext + IdeToolResult
esbuild.mjs — Path alias plugin for @libs-* resolution
tsconfig.webview.json — Extends tsconfig.base.json + rootDir fix
index.ts — Mounts agent-chat-view in #pane-agent-chat
package.json — Version bumped to 0.13.0

4. `@libs-foundational/core-models`

Added IDE RouteContext values: ide-editor, ide-terminal, ide-debug, ide-diff
Added ide-assistant CapabilityContext
Updated ROUTE_TO_CAPABILITY mappings

What's NOT Done

Item	Why	Next Session
Backend `/engine/agent-session` SSE endpoint	Not in scope — requires backend-vitto-api work	Recommended next
Keybindings (Cmd+Shift+V)	Polish, not blocking	P1
DiffContentProvider	Enhanced diff preview for write approval	P1
Extension package + install testing	Built & installed v0.13.0 but no end-to-end test with live backend	After backend endpoint
Git commits	Session ran concurrently with S254 — all changes uncommitted	Commit after merge coordination

Critical Conventions Established

Angular barrel avoidance — Framework-agnostic libs must never import from Angular barrel exports. Define local types or provider interfaces instead.
Webview esbuild dual resolution — Both tsconfig.webview.json (extends base) AND esbuild alias plugin are mandatory. rootDir must be set to monorepo root.
Extension reinstall workflow — Always use yarn ext:reinstall (runs build + package + install via proper Cursor CLI path).

Build Verification Commands

# All must pass:
npx tsc -p libs/libs-ai/chat-plugin-core/tsconfig.lib.json --noEmit
npx tsc -p libs/libs-ai/vitto-chat/tsconfig.lib.json --noEmit
npx tsc -p libs/libs-foundational/core-models/tsconfig.lib.json --noEmit
cd apps/vitto-vscode-extension && node esbuild.mjs

# Verify zero Angular imports in core:
grep -r "@angular" libs/libs-ai/chat-plugin-core/src/  # Should return nothing

# Verify zero .js artifacts leaked:
find libs/ -name "*.js" -newer tsconfig.base.json | head  # Should return nothing

# Reinstall extension:
yarn ext:reinstall

Spec & Plan References

Spec: docs/superpowers/specs/2026-03-22-chat-plugin-core-and-native-vscode-chat-design.md
Plan: docs/superpowers/plans/2026-03-22-chat-plugin-core-and-native-vscode-chat.md
Changelog: apps/vitto-vscode-extension/CHANGELOG.md

MCP Decisions Logged

ID	Type	Summary
`dev_1774285299880_tfisqdy`	architecture	Framework-agnostic plugin core extraction strategy
`dev_1774285314457_hi9j9ad`	architecture	Capability negotiation over static platform lists
`dev_1774285332221_3xteg9k`	bugfix	Angular compiler TS2353 error — wire vs stored type separation
`dev_1774285350425_wh1nuwi`	infrastructure	esbuild + tsconfig dual path resolution + rootDir fix
`dev_1774285370109_89fuihs`	convention	Angular barrel import avoidance in framework-agnostic libs

All 5 decisions reported as successful outcomes. 2 conventions added. 7 lessons captured in reflection.