Authentication

cursor-agent backend

The default backend uses the login owned by cursor-agent:

cursor-agent login

Check the session by asking the CLI for its model list:

cursor-agent models

Then confirm OpenCode sees the provider:

opencode models | grep cursor-acp

The two checks answer different questions. cursor-agent models confirms that Cursor accepts your login and shows which models your account can use. opencode models confirms that the plugin and provider configuration loaded.

OpenCode auth

You can also store Cursor credentials through OpenCode:

opencode auth login --provider cursor-acp

This matters when you select the SDK backend or when automatic backend selection needs an SDK fallback.

SDK backend

Set a real Cursor API key from Cursor settings when using CURSOR_ACP_BACKEND=sdk:

export CURSOR_API_KEY=<your-api-key>
export CURSOR_ACP_BACKEND=sdk

The SDK path also reads an API key from the OpenCode auth store or from the apiKey option in the cursor-acp provider block.

Do not use the historical cursor-agent placeholder as an SDK key. The SDK requires a real key.

What a failed login looks like

Authentication failures usually surface as Not authenticated, fetch() URL is invalid, or a provider error before any response tokens arrive.

Run:

open-cursor doctor
cursor-agent models

If cursor-agent models fails, sign in again. If it succeeds but opencode models | grep cursor-acp returns nothing, check Troubleshooting.