Choose an AI connection
MarkCluster works with Claude (Anthropic) and OpenAI. Pick how to connect in ⚙ Settings › AI connection.
Four ways to connect
| Connection | What you need |
|---|---|
| Claude API | An Anthropic API key (or ANTHROPIC_API_KEY) |
| Claude subscription | The official Claude Code, signed in with your Claude account |
| OpenAI API | An OpenAI API key (or OPENAI_API_KEY) |
| ChatGPT subscription | The official Codex CLI after codex login |
Click Test connection to send one very short request and check that everything works.
API keys
API keys are billed by the provider. MarkCluster stores the key only in its settings file on your computer and sends it only over encrypted connections.
Using the official CLI
If you already use the official Claude Code or Codex CLI, MarkCluster can call it for you. MarkCluster never reads or stores your login. Which plans work, and the limits and terms that apply, are set by Anthropic and OpenAI and may change — if it doesn't work for you, use an API key instead.