codespace/plan.md

# Plan

Roadmap for the next phases of the codespace web IDE.

## Now: shadcn/ui dialog and dropdown migration

The frontend still uses `window.prompt`, `window.confirm`, and an absolute-positioned `<div>` for the file-tree context menu. Replace these with shadcn/ui components backed by Radix UI primitives. This gives us:

- Consistent visual style for all popups
- Better keyboard navigation and accessibility
- The right-click context menu in the file tree becomes a real `DropdownMenu` instead of an in-place div

### Concrete steps

1. Add Radix UI primitives: `@radix-ui/react-dialog`, `@radix-ui/react-alert-dialog`, `@radix-ui/react-dropdown-menu`.
2. Add shadcn-style wrappers under `web/src/components/ui/`:
   - `dialog.tsx` (Dialog, DialogContent, DialogHeader, DialogTitle, DialogDescription, DialogFooter)
   - `alert-dialog.tsx` (AlertDialog, AlertDialogContent, AlertDialogHeader, AlertDialogTitle, AlertDialogDescription, AlertDialogAction, AlertDialogCancel)
   - `dropdown-menu.tsx` (DropdownMenu, DropdownMenuTrigger, DropdownMenuContent, DropdownMenuItem, DropdownMenuSeparator)
   - `input.tsx` (used inside Dialogs for prompts)
3. Migrate the existing callers:
   - `WorkspaceSelector.tsx`: replace `window.prompt` for new-workspace with a `Dialog` containing an `Input`. Replace `window.confirm` for delete with an `AlertDialog`.
   - `FileExplorerPanel.tsx`: replace all `window.prompt` (new file, new folder, rename) with a generic `Dialog` + `Input` component parameterized by title and callback. Replace `window.confirm` (delete) with an `AlertDialog`. Replace the absolute-positioned context menu with `DropdownMenu`.
4. Do not change backend behavior.

## Next: opencode ACP panel and integration

`opencode acp` exposes the editor as an **Agent Client Protocol** server. The current `opencode` process is started in the background but the user has no way to interact with it. The next phase adds a first-class ACP client panel in the web IDE.

**Status: ✅ Completed** (commits: ACP backend `feat(backend): add opencode ACP ...`, ACP frontend `feat(web): add ACP chat panel ...`, bug fix `fix(acp): parse session/update content as ContentBlock, not string`).

### Why

The terminal currently runs `bash` (the shell subsystem). The `opencode` process is started via the toolbar and is meant to be controlled by an ACP client — the same protocol that editors like Zed use to talk to coding agents. Without an ACP panel, the opencode process is invisible: it has a PID and a status indicator, but no way to send it prompts or read responses.

### Scope

1. **Backend: switch the opencode process to ACP mode**
   - Default `opencodeCommand` stays `opencode`; new `process.args` field defaults to `["acp"]` so the launched command is `opencode acp`. Configurable via `configs/config.yaml` and the `CODESPACE_OPENCODE_ARGS` env var.
   - The `internal/process` package still captures stdout/stderr and exposes stdin via the WebSocket. ACP over stdio sits on top in the new `internal/acp` package — no transport changes to the existing process WS route.

2. **Backend: ACP-aware HTTP API**
   - Implemented as four HTTP routes per ACP method. The frontend does not need to know JSON-RPC.
   - Routes:
     - `GET  /api/workspaces/:id/acp/status` — observational: `{workspaceId, ready, sessionId, running, pid, error}`. Does NOT start the process.
     - `GET  /api/workspaces/:id/acp/history` — accumulated `{sessionId, messages: [{role, text, time}]}`, oldest first. In-memory only.
     - `POST /api/workspaces/:id/acp/prompt` — body `{content: string}`. Returns `{sessionId, stopReason, text}`. Starts the process + session on demand (synchronous, 5-min default timeout).
     - `POST /api/workspaces/:id/acp/cancel` — best-effort interrupt.

3. **Frontend: ACP panel**
   - Implemented as `web/src/components/acp/AcpPanel.tsx` with subcomponents `MessageBubble`, `MarkdownView`, `ThinkingIndicator`. Renders markdown with code-block highlighting (react-markdown + react-syntax-highlighter Prism oneDark), with auto-scroll, error toast fade, and a "thinking…" indicator while in flight.
   - Hooks: `useAcpStatus` (3s poll), `useAcpHistory` (5s poll), `useAcpPrompt` (mutation), `useAcpCancel` (mutation).

4. **Frontend: integration with the workspace shell**
   - Bottom panel converted to a tabbed area: `Terminal` / `Agent` (decided on **Tabs + Sibling tab**, not replace, not split). Tab state lives in `workspaceUiStore.bottomTab`.
   - `StatusBar` shows `agent: ready` / `initializing…` / `<error>` pill when the ACP session is initialized; hides when not.
   - The existing `process/*` routes and raw process WebSocket remain untouched (the new acp routes are additive).

### Concrete tasks — all done

1. ✅ Switched opencode default to `opencode acp` via `process.args`.
2. ✅ Added `internal/acp` package: NDJSON transport + JSON-RPC 2.0 client (NDJSON framing with split-line buffering, request/response correlation, notification dispatch, per-workspace `Client` + `Service`).
3. ✅ Added `internal/api/acp_handler.go` with the four routes.
4. ✅ Added `web/src/lib/api/acp.ts` with the four hooks.
5. ✅ Added `web/src/components/acp/AcpPanel.tsx` + subcomponents.
6. ✅ Added `react-markdown` + `react-syntax-highlighter` + `remark-gfm` to `web/package.json`.
7. ✅ Wired the ACP panel into `WorkspaceShell.tsx` as a tabbed bottom panel.
8. ✅ Documented the ACP routes in `README.md` (section + env var + example curl).

### Tests
- `internal/acp/client_test.go` covers NDJSON split-lines, request/response correlation, notification dispatch, and agent-initiated request handling for `fs/*` (real dispatch) and `terminal/*` (MethodNotFound).
- E2E smoke test against the live `opencode acp` binary: created a workspace, sent a prompt, received `text: "Hi there!"` non-empty, history has 4 messages (1 user + 3 agent chunks), 0 `invalid session/update` log entries.

### Out of scope (deferred to v2)
- Streaming responses over WebSocket (v1 is single round-trip per prompt).
- Tool-call approval UI.
- Multiple agents / agent switching.
- Authentication.
- Cross-workspace agent memory.
- ACP session persistence across opencode restarts (history is in-memory and cleared on process restart — acceptable for v1).
- `terminal/*` agent tool calls (return `MethodNotFound -32601`; the agent will fail those tool calls gracefully).