DeepSeek builds an app store for agents. Your next channel: a plugin

Remember 2008? Apple opens the App Store and suddenly every brand needs an app. Most of them were pointless. The ones that did a real job are still on your home screen.

That moment is happening again. Only this time the one browsing the shelf isn't a person. It's an agent.

What DeepSeek announced

DeepSeek, the AI startup from Hangzhou, published its first numbers for Harness, its open-source agent app. The headline figures, all self-reported and not independently audited:

• 1.54 million daily active users as of November 4, counting people who use it through DeepSeek's official API. Around the end of September, shortly after the desktop app launched, the figure was about 271,000, according to Bloomberg.
• About 35,000 third-party plugins. Roughly 60% of active users have built or installed at least one.
• An official plugin marketplace is in the works, plus a support program for plugin authors with token grants, technical exchange and promotion. No date, no terms yet.

Harness itself is MIT-licensed, available as a public preview for macOS and Windows, and built on an "everything is a plugin" idea: even core features can be swapped out. You can have new plugins built for you right in the chat.

The number that matters isn't 1.54 million

The user count is self-reported and the methodology isn't public. Fine. The more interesting number is 60%. If most users extend their agent with plugins, the plugin shelf decides which services the agent even knows exist.

My rule of thumb: once personal agents do the pre-sorting, the agent decides what the customer gets to see. Marketing has to become legible to the agent. Until now that was a thesis about inboxes and offers. Plugin marketplaces give it infrastructure. A plugin is a distribution surface. If you're installed, you get called. If you're missing, the agent picks someone else.

This isn't just DeepSeek. Claude has Skills and MCP, ChatGPT has apps, Cursor and friends have their own extensions. DeepSeek simply shows how fast a shelf fills up when entry is free and open.

The catch

DeepSeek itself says community plugins vary in maturity. Translation: third-party code running in the middle of your work. Before a team runs an agent like this with plugins, it needs a rule for who can install what. Human in the loop isn't only for ads. It's also for the tools you hand your agent.

What I'd do now

• Run an agent audit. This week, check whether your product shows up in the agent ecosystems your customers use: as a skill, MCP server, app or plugin. Three columns are enough: platform, present yes/no, owner.
• Pick one job. Not a "brand plugin". A plugin that does something customers find annoying today: check availability, calculate a quote, book a slot.
• Set an install rule. Who on the team can enable plugins in agents, and who signs off? One page, no more.

Bottom line: The fight for the home screen is over. The fight for the plugin shelf just started.