Latest release · Cross-platform

Cowork CLI —
M365 Copilot in your terminal

The same Aether runtime that powers Copilot Cowork, now scriptable. Interactive REPL, full Terminal UI, SSE streaming, MCP server — one install on Windows, Mac, Linux, and WSL.

# Run PowerShell as Administrator
PS> irm https://aka.ms/cowork/ps1 | iex

⚠️ On Windows, the terminal must be run as Administrator (system-wide pip install).

Requires Python 3.11+. Auto-updates on every launch.

Get started See it in action
What you get

Everything Copilot does,
from the terminal

Cowork CLI connects to the same Aether runtime as the M365 Chat app. Same models, same skills, same connectors — scriptable, composable, and at-your-fingertips fast.

Live SSE streaming

Token-by-token responses with tool traces, thinking indicators, and file artifacts — no polling, no waiting for the full reply.

Terminal UI

Full-screen TUI with scrollable chat, tool panel, conversation sidebar, and keyboard shortcuts. Same runtime, premium UX.

MCP server

Expose Cowork as tools for Claude Code, VS Code Copilot, or any MCP client. Let your AI drive M365.

Context refs

Attach emails, meetings, people, files, and Teams chats to any message with --ref email:Q3 Budget.

Auto-update & retry

Checks for new versions on launch. Automatically retries on transient runtime errors so your session never just dies.

Single-shot & scriptable

cowork send "..." with --json output. Perfect for evals, automations, and pipelines at scale.

Live session

Feels like M365 Chat,
runs like a proper CLI

Streaming text deltas, live tool calls, file artifacts — rendered as Markdown with Rich and Textual in a terminal that's already open. 

$ cowork chat
Cowork Chat — alex.morgan@contoso.com on ia302
Model: opus-4.7 | Type /help for commands, /quit to exit

you> What meetings do I have tomorrow? Create a prep doc for the most important one.

  ⟳ SearchCalendar (1.2s) ✓
  ⟳ SearchEmails [research] (2.8s) ✓
  ⟳ CreateDocument (4.1s) ✓

You have 3 meetings tomorrow:
  • 10:00 AM — Q4 Strategy Review with Navid + VP team
  • 1:00 PM — 1:1 with your manager
  • 3:00 PM — Sprint Planning

I've created Q4_Strategy_Prep.docx covering last quarter's metrics,
open risks from your inbox, and three recommended talking points.

  📄 Q4_Strategy_Prep.docx (15.3KB)   /download 1 to save

[ok] 8.3s

you> /trace
─ Tool Trace ─────────────────────────────────
  1  SearchCalendar     ok  1.2s
  2  SearchEmails       ok  2.8s   (research subagent)
  3  CreateDocument     ok  4.1s
─────────────────────────────────────────────
Get started

Four commands to know

The whole workflow fits in muscle memory.

cowork auth login

Browser sign-in via MSAL. Works with any Microsoft tenant.

cowork chat

Interactive REPL with streaming, tool traces, slash commands.

cowork tui

Full-screen Terminal UI with panels, history, keyboard shortcuts.

cowork send "..."

Single-shot message with --json, --file, and --ref for scripting.

Built for evals

Run hundreds of prompts in parallel

The original reason Cowork CLI exists. The web UI can't scale for dataset-level evals — but a CLI composes with bash, xargs, GNU parallel, and Claude Code. Same runtime, same models, but at throughput.

Install and try 
# Parallel eval of 100 prompts
cat prompts.txt | xargs -P 10 -I {} \
  cowork send --json "{}" >> results.jsonl

# Or from Claude Code — just ask:
> Run these 5 M365 scenarios in parallel
> via cowork, then score each response