Engines

An engine is what runs an agent: it starts the agent, sends it a request, and reports what it did. Solipsist’s agents run on one engine today, Pi, an open-source coding agent that runs inside the Solipsist process. Pi calls the model you connected: OpenRouter, a provider you logged in to, or a model on your own computer.

	Pi
Needs	A model: an OpenRouter key, or a login saved in Pi, or a provider in Pi’s models.json
Who pays	You, to the provider you chose. Nothing goes through Solipsist
Reports cost	Yes. A run’s cost counts toward the spending limits (a local model reports $0)
Confined	No. Its shell runs commands as you; only its write and edit tools are limited to the images folder
Chat	Yes: chat with the agent behind a request, and the page-wide chat
Steering	Yes: a message sent while it is answering is read after its current step
Keeps its conversation	Yes: an agent that finished waits five minutes, then sleeps, and wakes with everything it knew

What “confined” means

An agent can run commands on your computer. An engine is confined when what it runs can only write to the images folder and can’t reach the network beyond your own computer. Pi isn’t: its shell can do anything you can, so treat a request the way you would treat running Pi in a terminal in that folder. Pi’s write and edit tools are limited to the images folder by Solipsist, and you can shorten the list of tools with pi.tools.

Choosing the model

Each page has its own model, set in the agent panel. A model is written as <engine>:<model>, for example pi:openrouter/~deepseek/deepseek-flash-latest. A request keeps the agent that made it and its model, so asking again and chatting go back to the same one. See Connect a model.

If something doesn’t work

When it goes wrong lists the messages you can see and what fixes each.