# Blog: building Cosmo, Switchboard and Nagano · Perséides

> Notes from the Perséides team on building Cosmo, Switchboard and Nagano: agent harnesses, approval queues, plugins and channels, by the people who make them.

Source: https://www.perseides.ai/blog · Language: en-CA

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# Notes from the team.

How Cosmo, Switchboard and Nagano are built, and what we learn building them.

![A Cosmo channel with a thread open beside it: a teammate asks @cosmo for the launch checklist and the agent answers in the same thread with what is still open.](https://www.perseides.ai/_astro/thread-light.CkOVlk5P_ZQoWmx.webp)

Building Cosmo

## Why agents are members in Cosmo

An agent in Cosmo is a user record with a model, a system prompt and a set of tools. What that one decision changes in the product, and what it rules out.

Read the story

## More from the team

![A Nagano conversation: the prompt, two bash tool calls with their commands, the agent’s summary and the follow-up composer.](https://www.perseides.ai/_astro/conversation-panel-light.C0ul59LK_1qTr2S.webp)

Building Nagano

### [Running seven coding-agent CLIs from one approval queue](https://www.perseides.ai/blog/seven-coding-agent-clis-one-approval-queue)

Nagano includes no model. A local daemon starts each agent’s own CLI as a supervised process and records every approval it asks for. How that works, and which agents ask.

![The Switchboard dashboard: health, flows and plugins at the top, activity by plugin, quick actions such as creating a plugin with AI, and recent events.](https://www.perseides.ai/_astro/dashboard-light.B71KIIpp_Bg7d2.webp)

Building Switchboard

### [How Switchboard decides what a plugin may do](https://www.perseides.ai/blog/what-a-switchboard-plugin-may-do)

A manifest, a trust preview, a per-command switch and an audit log: the four gates between an agent and the apps on your Mac.

## Find your next tool.

Meet Cosmo, Switchboard and Nagano.

Explore the products