How do founders reply to email and Slack faster?
The short version: Stop typing every word. Opsis writes your next line wherever you type: Slack, Gmail, Outlook, Teams, Notion, Google Docs and AI chats like Claude and ChatGPT. Press Tab to keep it. It can also draft a whole reply from a few notes, using facts from your own work: what's on your screen, the apps you connect (Gmail, Calendar, Drive, Slack, Notion, GitHub, Linear, Outlook) and your history. Founders get a lot of messages whose answer is already in their own docs, calendar or earlier threads. Opsis uses those so the draft arrives with the fact in it.
It is not an inbox manager. It doesn't triage, archive or decide what matters. It helps once you open a message and start to answer.
How it compares.
Tools founders use for replies, as of November 2026
| Tool | Best for | Where it works | Notes |
|---|---|---|---|
| Opsis | Writing the reply once you are in the message. | Slack, Gmail, Outlook, Teams, Notion, Docs, AI chats. | Not a triage tool. |
| Superhuman Go | An assistant that works from what is on your screen. | Windows and Mac. | From the company formerly called Grammarly. Check plan limits. |
| Shortwave, Spark | Email inbox with AI features. | Their own email apps. | Email only. |
| Gmail Smart Compose | Common phrases in Gmail. | Gmail. | Free, built in. |
Swipe the table to compare
Figures and shutdown dates come from the sources at the bottom, or from this site's own product copy. We don't invent competitor features.
Who it's for.
Startup founders and operators who answer Slack, Gmail and AI chats all day and want to reply in seconds without sounding generic.
Your data.
Opsis only follows the apps you share. Private windows and password managers are never recorded. When assistance is on, the text it needs is processed in the cloud with your consent, encrypted in transit and at rest, with zero data retention at our AI providers. Opsis isn't a screen recorder. You can pause, disconnect an app or delete your history whenever you like. Read the privacy policy · How Opsis handles data.
A routine that works
Open the message. Type three to six words of what you want to say. Read the draft. Press Tab if it is right, edit if it is close, ignore it if it is wrong.
FAQ
Does Opsis read my whole inbox?
It uses what you share and connect, and only when assistance is on. You can disconnect Gmail or pause Opsis at any time.
Is it a Superhuman replacement?
No. Superhuman is an email client. Opsis works inside the apps you already use.
What does it cost?
Free to start. Pro is $15 a month.