Claude Activity Viewer

A read-only activity viewer for your Claude Code agents. Whenever Claude Code spawns sub-agents, they show up live in a VS Code sidebar — model, context usage, status and recent sessions — without leaving the editor.

What it does

When you work in Claude Code, a single chat often fans out into several sub-agents — one exploring the repo, one running tests, one searching for a pattern. They run, finish, and disappear into the transcript.

Claude Activity Viewer gives them a window. It listens to Claude Code's own activity hooks and renders every sub-agent in a sidebar dashboard: what's running now, what's queued, what just finished, grouped by project and session. Click any agent to open a detail panel with its live log plus the model, token count and context usage read straight from the session transcript.

It's read-only — it observes, it never spawns, cancels or drives agents. Nothing about your Claude Code workflow changes; you just gain visibility into it.

Related MCP server: Agent Communication MCP Server

Why use it

• See your sub-agents. A live NOW PLAYING / UP NEXT / RECENT board for every agent Claude Code launches, grouped by project, session and working directory.

• Know what each agent is doing. Per-agent detail panel with the streaming log (thinking, tool calls, tool results) and the model + tokens + context% pulled from the transcript.

• Spot stalls. Running agents pulse while active; an agent that goes quiet for a while is flagged as idle without being dropped from the board.

• Pick up past work. A scanner reads your ~/.claude/projects/ history and lets you resume a past session in the Claude Code chat or a new terminal.

• Stay in the editor. A status-bar count of running agents, and a toast when each one finishes.

Install

1. Download claude-activity-viewer-0.3.0.vsix from Releases.

2. Install it: code --install-extension claude-activity-viewer-0.3.0.vsix (or right-click the .vsix in VS Code → Install Extension VSIX).

3. Reload VS Code.

4. Run Claude Activity Viewer: Install global activity hooks from the Command Palette (Ctrl+Shift+P). This is a one-time step — it writes the activity hooks into your global ~/.claude/settings.json so every Claude Code session streams its agents into the dashboard.

Prerequisites: Claude Code CLI installed and signed in (claude login). VS Code 1.120+, Node 22+.

First view (60 seconds)

1. Open the Claude Agents view from the Activity Bar — the dashboard sidebar appears.

2. Start a Claude Code session that spawns sub-agents. For example, in any Claude Code chat:

   Lanza 3 subagentes en paralelo (read-only): uno que mapee la estructura del repo, uno que busque los TODO/FIXME, uno que resuma los archivos de config.

3. Watch NOW PLAYING fill with the running agents — pulsing, grouped under their project and session.

4. Click any card to open its detail panel (an editor tab) with the live log and the model / tokens / context% from the transcript.

5. When they finish, they move to RECENT with their real duration.

What's inside

• Sidebar dashboard — NOW PLAYING / UP NEXT / RECENT, grouped by project · session · directory, with a short session id and branch in each group header.

• Liveness indicator — running agents pulse; one that stops emitting activity is marked idle (without leaving the board); finished agents show their honest duration.

• Detail panel in an editor tab — per-agent streaming log (thinking, tool calls, tool results) plus ModelBadge, token count and a context-usage bar, all read on demand from the session transcript.

• Completion toast — an optional notification when an agent reaches a terminal state, with a shortcut to open its detail panel.

• Session scanner — parses your ~/.claude/projects/*.jsonl history into the RECENT lane and offers to resume past sessions in the chat or a new terminal.

• Status bar — a live count of running agents (click to focus the dashboard).

Configuration

Settings live under File → Preferences → Settings → Extensions → Claude Activity Viewer. The defaults are sensible — touch these only if you're tuning.

How it works

Claude Code session ──hooks──▶ NDJSON spool ──tail──▶ ingester (translator)
                                                          │
                                       ┌──────────────────┘
                                       ▼
                              read-only store (bridge) ──postMessage──▶ Vue sidebar
                                                                            ▲
~/.claude/projects/*.jsonl ──session scanner──────────────────────────────┘ (RECENT / resume)

The activity hooks (SubagentStart / SubagentStop / Stop / SessionEnd) append events to a spool file; the extension tails it, translates each event through a per-agent state machine, and feeds a read-only store that the Vue dashboard renders. The session scanner is an independent pipeline that reads your past .jsonl transcripts for the RECENT lane and resume. Per-agent metrics (model, tokens, context%) are read from the transcript on demand when you open a detail panel.

git clone git@github.com:stevTresCloud/claude-activity-viewer.git
cd claude-activity-viewer
npm install
npm run compile      # bundle extension + webview
npm run typecheck    # tsc (extension) + vue-tsc (webview)
npm test             # vitest
npm run package      # typecheck + production build (input to vsce)

In VS Code, press F5 to launch an Extension Development Host with the extension loaded.

Caveats

• Single detail panel at a time. Clicking a different agent replaces the current detail panel; multi-panel side-by-side is on the roadmap.

• No cost figure. The viewer reads the transcript, which carries token usage but not a dollar cost, so per-agent cost is not shown.

• First scan latency. With many past Claude Code sessions the first scan can take a while; subsequent activations hit a cache.

License

MIT — see LICENSE.

Credits

Dashboard UX inspired by manusa/ai-beacon (Apache-2.0); the agent-board schema is informed by hoangsonww/Claude-Code-Agent-Monitor (MIT).

See THIRD-PARTY-NOTICES.md for bundled software.