Multiple accounts

Sign in to as many Claude Code, Codex CLI, or OpenCode accounts as you use. A work account and a personal account can sit side by side, each with its own sign-in and its own usage limits, and you choose which one a chat runs as.

Add another account

1. Open Extensions → Harnesses and click the agent's card.
2. In the Accounts section, click Add account. The new row is named after the agent with a number, for example Claude Code 2.
3. Click Sign in on the new row and sign in the same way as the first account. You can use a different plan, or an API key, for each one. For OpenCode, each account keeps its own set of provider keys.

The agent needs to be installed before you can add an account; turn it on first if it is not.

Name your accounts

Open the row's menu and choose Rename to give an account a name you will recognize in the composer, such as Work or Personal. The signed-in email also shows under each account wherever you choose one.

Choose an account for a chat

In the composer, open the model picker and look under Harness. Each agent lists its accounts, so pick the one the chat should run as. Mach Studio remembers the choice for that chat. To move an existing chat to another account, see Switch agents and models.

Keep accounts separate

Each account keeps its own credentials and its own chat history inside Mach Studio. Mach Studio never reads or forwards your credentials, and signing in here does not touch any sign-in you already have in your terminal.

Sign in again or remove an account

From the row's menu:

• Sign in again refreshes an expired login or swaps an API key.
• Remove signs the account out of Mach Studio and deletes the credentials and chat history it keeps here. Your chats keep their transcripts, and your terminal sign-in is untouched.