> ## Documentation Index
> Fetch the complete documentation index at: https://radiusbrowser.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Agents

> Connect Codex, Claude, or Cursor to Radius.

Radius includes built-in integrations for Codex, Claude, and Cursor. Radius
bundles the required agent runtimes, so you don't need to install their
command-line tools separately.

## Supported agents

| Agent  | Radius bundles               | Connection options     |
| ------ | ---------------------------- | ---------------------- |
| Codex  | Codex app-server             | **CLI** or **API Key** |
| Claude | Claude runtime and Agent SDK | **CLI** or **API Key** |
| Cursor | Cursor Agent SDK             | **API Key**            |

Radius controls and updates the bundled runtime. The agent still controls its
native configuration, provider behavior, and supported models.

## Choose how to connect

Open **Radius Settings → Agents**, select an agent, and choose a connection
method.

### Use your existing or custom setup

Choose **CLI** for Codex or Claude when you want Radius to use the setup you
already have. This includes:

* A Codex or Claude subscription login
* Azure OpenAI or Amazon Bedrock for Codex
* A compatible Google Cloud or other custom Codex endpoint
* Bedrock, Vertex AI, or Foundry for Claude
* Custom endpoints, model mappings, or provider environment variables

Radius launches its bundled runtime with your normal agent home and shell
environment. The runtime then reads and applies your native configuration.

| Agent  | Default home | Configure with                                                           |
| ------ | ------------ | ------------------------------------------------------------------------ |
| Codex  | `~/.codex`   | `config.toml`, `CODEX_HOME`, and provider environment variables          |
| Claude | `~/.claude`  | Claude settings, `CLAUDE_CONFIG_DIR`, and provider environment variables |

You don't need a configuration file for a standard subscription login. If the
agent isn't connected, Radius can start its native sign-in flow.

### Connect directly in Radius

Choose **API Key** when you want Radius to manage a direct provider key:

| Agent  | Key               |
| ------ | ----------------- |
| Codex  | OpenAI API key    |
| Claude | Anthropic API key |
| Cursor | Cursor API key    |

Radius encrypts the key and runs the agent with an isolated configuration. Your
normal login, configuration, and ambient provider credentials don't take over.

## How Radius reports available models

After connecting, Radius asks the bundled runtime which models are available.
The runtime determines availability and native defaults. Radius controls the
model selected for a new chat or the current conversation.

Changing an agent's connection method affects new chats. Existing chats keep
the connection and native session with which they started.