---
title: "Configuration"
description: "How Cetas is configured — in conversation, with commands, or by hand."
---

> Documentation Index
> Fetch the complete documentation index at: https://colmugx.github.io/cetas/llms.txt
> Use this file to discover all available pages before exploring further.

# Configuration

## Try the lowest-effort path first

Once it is installed, describe the change in the session and let the agent
write the settings:

```text
Add a provider named my-gateway at https://llm.internal.example/v1,
declare the model qwen3-32b, and make it my model.
```

Ask for a diff of what it wrote. Provider entries, model metadata, subagent
kinds, workflow budgets — all of it can be configured this way, and for most
changes this is where the work ends. See
[Natural-language configuration](/cetas/en/configuration/natural-language/).

## What a picker covers, do with commands

`/login`, `/model`, `/decision`, and `/effort` write the shape the selected
provider expects, so no schema to learn. The full list is in the
[command reference](/cetas/en/reference/commands/).

## Reference pages for editing the file

To check fields one by one, copy configuration between machines, or provision a
batch of environments, these pages follow the structure of settings.json:

- [Settings reference](/cetas/en/reference/settings/) — the complete field
  reference: every key, its type, its default, expanded by nesting level;
- [Providers](/cetas/en/configuration/providers/) — the built-in provider set and
  login;
- [Models](/cetas/en/configuration/models/) — slots, `/model`, and `/decision`;
- [Custom and self-hosted models](/cetas/en/configuration/custom-models/) — the entry
  shape for private endpoints and gateways;
- [Subagents](/cetas/en/configuration/subagents/) — kind definitions and tool
  whitelists;
- [Permissions](/cetas/en/configuration/permissions/) — what the agent may touch;
- [Skills](/cetas/en/configuration/skills/) — load reusable instruction packs;
- [MCP](/cetas/en/configuration/mcp/) — connect external tool servers;
- [Cetas Home](/cetas/en/configuration/cetas-home/) — the directory itself.

## What is shared, and what is not

Sharing one home means every surface reads the same configuration, credentials,
and session store. It does **not** mean every surface behaves identically: the
terminal has pickers, the editor has ACP config options, and the runner takes
flags. Each surface page states what it supports.

Selections made in one surface are visible to the next: `/model` in the terminal
is what the editor restores on its next start.

> **Changes land in the next session**
>
> The system prompt is assembled once per session and frozen. Settings that affect
> it — instructions, provider identity, skill catalog — take effect when you start
> a new session, not on the running one. Selections such as `/model` and `/effort`
> apply immediately.

Source: https://colmugx.github.io/cetas/en/configuration/index.mdx