Agents won't start or respond

Work down this list — it’s ordered by how often each cause is the culprit: the CLI isn’t installed, the CLI isn’t signed in, the key isn’t set (or a stale window is running), or the task hit an error the transcript explains.

The window says the CLI isn’t available

Cause: the agent’s binary isn’t installed or isn’t on your PATH.

1. Open Settings → Agents — the detection list shows every brand with found/not-found and an Install hint.
2. Install the CLI (each brand’s official installer), then click Scan again.
3. Open a new agent window of that brand.

The agent replies with a login/authentication error

Cause: the CLI isn’t signed in and no API key is set.

1. Easiest: run the CLI once in a terminal outside Mastery HQ and complete its login flow.
2. Or set its API key in Settings → Agents → Agent API keys (.env), click Recheck keys, and open a fresh agent window. (Key guide)
3. The transcript shows the exact login instruction for the brand when this happens — follow it verbatim.

I added a key but the agent still fails

Cause: running windows keep their original environment.

1. Close the agent window and open a new one — new windows pick up the current .env.
2. Check for a project-level .env in the workspace folder overriding your global keys.

The run starts, then exits immediately with a code

Cause: the task itself errored — the CLI’s message is in the transcript just above Process exited.

1. Read the last lines before the exit; they name the problem (rate limit, invalid flag, network).
2. Retry once; if it persists, run the same prompt in that CLI directly in a terminal to see its full output.

Nothing happens at all when I press Send

1. Confirm you’re in the desktop app (agents require it — the browser preview can’t spawn processes).
2. Check who’s working — if the agent is mid-run, new input waits its turn; Stop first to interrupt.

Still stuck?

Export the transcript (Export button) and send it via Feedback with the agent brand and what you expected.