Companion is a native AI desktop assistant for Windows and macOS. If you've just downloaded it — or are deciding whether to — this is the full walkthrough: every screen, every feature, what it does and why it's there.
First launch: onboarding
After installing, you're greeted with a clean welcome screen. One click signs you in securely through your browser — standard OAuth, nothing typed into the app itself.
Once signed in, Companion introduces itself and asks for a few basics: your name, preferred language, and optionally your gender and date of birth for personalization features like Ecco (the voice assistant).
Then it offers to connect your most-used apps — Gmail, Zoom, Spotify, Microsoft 365. You can connect them immediately or skip and configure later. Everything is reversible.
The whole onboarding takes about two minutes.
The main interface
The core of Companion is a chat interface. At the bottom: an input box for text prompts, voice commands, or file attachments.
Above it: quick action buttons for the most common task types — composing emails, creating documents, running research. These are shortcuts, not limitations. You can type any prompt.
On the top left: model selector. You pick which AI model handles your request — Claude Sonnet, GPT-4o, Gemini 2.5 Flash, or any of the 11+ models available via OpenRouter. Different tasks benefit from different models, and you can switch mid-conversation.
On the top right: zoom control for the interface size.
The smart sidebar
The collapsible left sidebar is your navigation hub:
- New conversation — start fresh without losing previous chats
- Chat history — scroll back through past sessions; context is preserved
- Settings — account, API key, integrations, system prompt
- Subscriptions — plan status, token usage, trial tracking
- Light/Dark mode toggle
- Help center — in-app access to documentation and support channels
The sidebar collapses completely when you don't need it, giving you a clean, distraction-free chat interface.
Settings: what's inside
Account: name, email, personalization preferences set during onboarding. Change them any time.
API Key: where you paste your OpenRouter key. This is the BYOK (Bring Your Own Key) configuration — your key is stored locally, encrypted with AES-256, and never sent to Companion's servers.
System Prompt: a custom instruction Companion follows in every conversation. Set your working style, preferred response format, or role context here. For example: "I'm a freelance developer. Always respond concisely and include code examples when relevant."
Integrations: the MCP hub. Install, connect, and manage all your integrations — Gmail, Calendar, Notion, Slack, GitHub, Spotify, and 100+ more. Each integration is one-click install followed by OAuth authorization.
Model switching: BYOK in practice
Companion routes all AI requests through OpenRouter, giving you access to 11+ models with a single API key:
- Claude Haiku 3 — fastest, cheapest, great for simple tasks (emails, quick lookups)
- Gemini 2.5 Flash — strong at structured tasks, very cost-efficient
- Claude Sonnet — best all-rounder for complex tool use
- GPT-4o — strong at long documents and nuanced writing
- Claude Opus — maximum reasoning, for the hardest tasks
Because you're paying OpenRouter rates directly, switching to a cheaper model for a simple email saves real money. A day of smart model selection typically costs $0.10–0.60 total, compared to $20–30/month for fixed-model AI subscriptions.
Usage and analytics
Under Settings → Usage, Companion shows a live dashboard of your token consumption and costs per session. Every message shows which model was used and how many tokens it cost.
This transparency is intentional. With BYOK, your costs are real and direct — Companion makes them visible so you can optimize. Most users find their daily cost is far lower than expected.
Integrations: the real power
Companion's integrations are MCP (Model Context Protocol) servers — a standard that gives AI access to real tools. Once installed, they turn Companion from a chatbot into an agent that acts across your actual apps.
The integration list includes: Gmail, Google Calendar, Google Drive, Notion, Slack, GitHub, Trello, Shopify, Zoho, Odoo, Discord, Telegram, Spotify, Calendly, YouTube, Microsoft 365, and more.
Each integration takes about 60 seconds to set up. Once connected, any prompt that involves that app routes through the integration automatically.
Voice: Ecco
Ecco is Companion's voice mode. Hold the designated shortcut, speak your prompt, and Companion responds — optionally reading the response aloud.
It's designed for hands-free workflows: dictating emails while walking, running searches while your hands are busy, or just preferring to talk rather than type.
What Companion is optimized for
Companion is built for multi-step, cross-app tasks. Single-app queries are fine, but the real value shows up when a prompt spans multiple tools:
- Research → document → email → calendar meeting in one prompt
- Email triage → label → draft replies → schedule follow-ups
- Slack digest → action items → Trello cards → team notification
The integrations stack. The AI holds context across all of them. The result is work that used to take 30 minutes happening in 30 seconds.
Download Companion — it's free, BYOK, and takes about 5 minutes to set up your first integration.