The multi-modal interface

Software used to have one interface. Now the best apps support clicking, typing, touching, and talking to AI; all at once. The winners will be the ones that let you interact however you want.

Every piece of software has an interface. That’s obvious. What’s changing is how many interfaces it needs.

We used to think in a single mode. Desktop apps were designed for a mouse. Click buttons, drag sliders, navigate menus. Photoshop is the extreme version of this; hundreds of tiny buttons, panels everywhere, built for precision pointing. Then over the last few years we’ve seen a de-cluttering of those buttons. The command bar popped up, reachable via cmd+K in apps like Notion, Linear, Raycast. Allowing you to type in the tool you’d need.

Then we have mobile. Entirely different in terms of interaction. A touch is different from a click. Buttons got bigger. Interfaces got simpler. Gestures like swiping, pinching, pulling became intuitive and expected. Though maybe tablets made it a bit weird. An iPad with a keyboard and trackpad behaves like a laptop. Flip the keyboard off and it’s a giant phone. The same device, two completely different interaction models.

But here’s where it gets interesting. The oldest interface is making a comeback.

The command line interface. The original computer interface, before everything went graphical, is growing again. AI coding assistants live in the terminal. Apps like Obsidian and Google Workspace have announced first-party CLI support, in order to be operable by AI agents. This developer-first workflow is increasingly text-command-first. And it’s not just for developers anymore. Apps are exposing programmatic interfaces to a much wider audience.

APIs have been the backbone of B2B software for years. CommerceTools, the commerce engine, is API-first by design. It doesn’t even pretend to be a complete application, it’s a platform developers build on top of. Notion opened up full read-write access through its API. Now MCP servers (Model Context Protocol) add another layer. They’re essentially abstraction layers on top of REST or GraphQL APIs, designed specifically for AI agents to interact with applications. Your app doesn’t just serve humans anymore. It serves other software.

The apps that are going to win are the ones that support all of these modes simultaneously.

Linear gets this right. It’s keyboard-first for power users. It has a beautiful click-based GUI for everyone else. It works on mobile with touch. It has a CLI. It has an API. It has MCP support. Every type of user, every type of device, every type of interaction covered.

That’s the new bar. Not just a great UI. A great interface. Plural.