Copilot CLI Agent Observer

Real-time observability for GitHub Copilot CLI agent sessions.

See what your AI agents are actually doing — every tool call, every subagent spawn, every message — in a live native dashboard that runs alongside your terminal.

Prerequisites

Requirement	Details
GitHub Copilot CLI	Installed and working (copilot command available)
Experimental mode	Enable with /experimental on or copilot --experimental
Node.js	v20.11+ with node and npm on PATH
Platform	Windows (x64), macOS (arm64/x64), Linux (x64)

Install

This is a Copilot CLI extension, not a plugin. Do not use copilot plugin install or copilot plugin marketplace add — those commands will fail with File not found: marketplace.json. Use the extension install below.

PowerShell

irm https://raw.githubusercontent.com/Rogn/copilot-cli-agent-observer/master/install.ps1 | iex

bash

curl -fsSL https://raw.githubusercontent.com/Rogn/copilot-cli-agent-observer/master/install.sh | bash

After install:

• Already in Copilot CLI? Ask Copilot to reload extensions (extensions_reload), then run /observer.
• Starting fresh? Run copilot --experimental, then /observer.

Manual install: clone this repo and copy .github/extensions/agent-observer to ~/.copilot/extensions/agent-observer.

Run /env to confirm agent-observer appears under Extensions.

Usage

Open the observer window:

/observer

/agent-observer also works as an alias.

Or ask the agent: "Open the agent observer" — the agent_observer_show tool works via natural language too.

Available tools

Tool	Description
agent_observer_show	Open the observer window (or bring it to front)
agent_observer_close	Close the observer window
observer_dump_summary	Structured JSON summary of captured events and diagnostics

Demo

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Troubleshooting

/observer shows "Unknown command: observer"

1. Ask the agent to run observer_dump_summary — confirm version is 1.4.0 or later. If older, reinstall with the script above.
2. Workaround: ask the agent to "open the agent observer" or call agent_observer_show directly. The tool always works, even when the slash command doesn't.

/observer doesn't appear in the command list

1. Run /env — agent-observer should appear under Extensions
2. If not, ensure experimental mode is enabled (copilot --experimental)
3. If listed but command missing, ask Copilot to reload extensions (extensions_reload)

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Compatibility

Platform	Webview engine	Status
Windows (x64)	WebView2 (Edge/Chromium)	✅ Known-working
macOS (arm64/x64)	WKWebView (Safari)	⚠️ Untested
Linux (x64)	WebKitGTK	⚠️ Requires libwebkit2gtk-4.0

Key limitations: Alpha quality · Read-only (cannot influence agents) · Requires experimental mode · No session persistence · Extension APIs may change across CLI releases

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Origin & Acknowledgements

This project started as a response to github/copilot-cli#1322 — the need for parent-session observability when working with subagents. Built on the copilot-webview-creator pattern by Steve Sanderson. Native window powered by @webviewjs/webview.

License

MIT