Connect Codex and Claude
On this page
boxes.dev runs Codex and Claude Code on your devboxes with your own agent accounts. Sign in with ChatGPT to connect Codex, or with Claude to connect Claude Code; either agent can also use an API key. You'll need at least one connected agent to start an agent task, and you can connect both to choose between them for different tasks.
Connect an account
- In the desktop app's sidebar, open Settings → Configure agents…. On macOS, you can also choose boxes.dev → Configure agents… in the app menu.
- Choose Add beside the agent. For Codex, choose Log in with ChatGPT; for Claude Code, choose Log in with Claude. Either agent also offers API key.
- Complete the browser sign-in. For an API key, enter the key and choose Save.
- If you've saved more than one account or key, select the radio control next to the one you want to use.
Your Codex and Claude selections are independent, so each agent can use a different account. Agent subscription limits and API charges come from the connected provider, separately from boxes.dev machine usage.
Change the account an agent uses
Open Configure agents… and select the radio control beside another saved account or API key. Your new selection will apply across your devboxes, but a thread whose agent is already running may keep using the account it started with and may show that account's usage limits.
Use a saved account's ⋯ menu to Re-authenticate, or a key's menu to Edit API key. Remove will delete that saved credential. If you remove the active one, boxes.dev will select another usable saved credential when one is available; otherwise, the agent will be disconnected. The confirmation will show which outcome to expect before you remove it.
Connect or reconnect from your phone
You can also manage these accounts from the mobile app. Open Settings → Agent accounts, then tap Add beside an agent, or tap a saved account to use it, re-authenticate it, check it, or remove it.
- Codex: tap Log in with ChatGPT, then Open ChatGPT. The app will copy the one-time code it shows. Sign in to ChatGPT if asked, paste the code, and approve. Codex will connect once you approve, even if you approve in another browser.
- Claude Code: tap Log in with Claude, then Open Claude and approve access. Copy the code Claude shows, return to the app, paste it, and tap Continue.
Repair a connection
If you're starting a thread with an agent that isn't connected, boxes.dev blocks sending and shows Set up Codex or Set up Claude. Select that action to open Configure agents, connect the agent, then come back and send your prompt. For an expired sign-in, reconnect the account or select another saved credential before retrying.
In the mobile app, a banner shows at the top of the screen when the account an agent uses needs you to sign in again. Tap Reconnect to sign in, or open Settings → Agent accounts to choose another saved account.
Some tools an agent uses have their own sign-ins, separate from the agent account. If the agent can respond but one of its tools needs a sign-in, repair that connection under MCPs or agent plugins.