# Claude Code and Codex (/integrations/claude-code-and-codex)



A harness is the agent program that does the work inside a sandbox. Mogplex
runs three harnesses:

| Harness     | ID            | What runs                                                                          |
| ----------- | ------------- | ---------------------------------------------------------------------------------- |
| Mogplex     | `mogplex`     | Mogplex's native agent. It is always available and uses any model in your catalog. |
| Claude Code | `claude-code` | Anthropic's `claude` CLI, in the sandbox.                                          |
| Codex       | `codex`       | OpenAI's Codex, in the sandbox. It runs through the Agent Client Protocol (ACP).   |

Mogplex installs a pinned version of Claude Code or Codex in the sandbox for each
run, gives it the repository checkout, and streams its events into
[Observability](/web/observability). Claude Code runs also receive your MCP
connections; see [where connection tools load](/configure-and-extend/connections-and-mcp#where-connection-tools-load).

## Requirements [#requirements]

Claude Code and Codex need model access. Each harness is available when you have
one of these:

* **Claude Code:** an AI Gateway key, Mogplex platform AI on your plan, or an
  Anthropic key.
* **Codex:** an AI Gateway key, Mogplex platform AI on your plan, or an OpenAI
  key.

Add keys in **Settings → Provider Keys**. See
[AI provider keys](/integrations/ai-provider-keys) for the order in which keys
are used.

## Choose a harness [#choose-a-harness]

| Where                                        | How                                                                                                                                                         |
| -------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [Automations](/web/automations)              | Select the agent node, then choose **Harness** in the inspector. Unavailable harnesses are disabled.                                                        |
| Slack                                        | `/mogplex harness claude-code`, `/mogplex harness codex`, or `/mogplex harness mogplex`. The choice applies to your future repository runs in that channel. |
| [Hosted API](/reference/api) and [MCP](/mcp) | Pass `harness` when you start a run. The API defaults to `codex`.                                                                                           |

## Run modes [#run-modes]

Claude Code and Codex runs accept a mode that controls what the harness can do
in the sandbox:

* `SAFE`: the harness does not change the checkout.
* `AUTO` (default): the harness edits files and runs commands.
* `YOLO`: the harness runs without approval prompts. Claude Code still blocks
  its deny-listed tools and commands.

The Mogplex harness takes no mode. See [Start a run](/reference/api#start-a-run)
for the details.

## Use Mogplex from Claude Code or Codex on your machine [#use-mogplex-from-claude-code-or-codex-on-your-machine]

This page covers Claude Code and Codex running **inside** Mogplex. To let a
local Claude Code, Codex, Cursor, or OpenCode session call Mogplex, install the
[Mogplex MCP endpoint](/mcp/install).