Overview
Compare the harnesses Conductor can run and where each one is configured
Conductor can run Claude Code, Codex, Cursor, and OpenCode sessions in isolated workspaces. A harness is the agent runtime that writes code; Conductor is the workspace layer around it.
Claude Code, Codex, and OpenCode come bundled in Conductor. You do not need to install them separately. Cursor sessions use Cursor Agent through the Cursor API.
Conductor is free to use. We do not bill or resell model usage. Harness usage is billed through the provider account or API key.
How the layers fit
Conductor sits above the agent runtimes. Each session chooses a harness, and each harness exposes models.
| Layer | Role | Example |
|---|---|---|
| Conductor | Orchestrates repositories, workspaces, sessions, terminals, diffs, checks, and pull requests. | One Mac app coordinating many isolated workspaces. |
| Harness | Runs the agent loop and tool calls that expose a model to the workspace. | Claude Code, Codex, Cursor, OpenCode. |
| Agent session | A running chat attached to one workspace, one harness, and one selected model. | One Codex tab on a branch. |
| Model | Provides the language and coding capability used by the harness. | Claude, GPT, Composer, or an OpenCode provider model. |
Harness comparison
The harness decides the agent runtime, setup path, model access, and billing owner.
| Harness | Availability | Setup | Billing |
|---|---|---|---|
| Claude Code | Conductor includes a managed Claude Code executable. You can use your own Claude Code install instead. | Claude Code auth, Claude subscription access, API billing, or provider environment variables. | Claude subscription, Claude Console or API credits, or provider billing. |
| Codex | Conductor includes a managed Codex executable. You can use your own Codex install instead. | OpenAI or Codex sign-in, API-key configuration, model access, and local Codex settings. | OpenAI subscription, ChatGPT credits, or API-key billing. |
| Cursor | Cursor Agent sessions through the Cursor API. Requires a Cursor API key. | CURSOR_API_KEY in Settings -> Harnesses -> Cursor, or Conductor environment settings. | Cursor plan, API usage pools, API key, and on-demand usage. |
| OpenCode | Conductor includes a managed OpenCode executable. You can use your own OpenCode install instead. | Settings -> Harnesses -> OpenCode for provider keys, visible models, and the OpenCode executable path. | The selected OpenCode provider, such as OpenCode Zen or Go, OpenRouter, Baseten, Cerebras, Vercel AI Gateway, ChatGPT, Copilot, or a local model. |
Session behavior
Each chat tab uses one harness and one selected model.
Separate workspaces have separate branches and pull requests. Multiple chats in one workspace share the same branch and current code state.
For session controls, see Agent modes. For setup examples, see Configure model providers.