Getting started

Go to app.custosai.eu/register and sign up with your email address. No credit card required — you get a 14-day free trial on whichever plan you choose.

After registering, check your inbox for a confirmation email. Click the link to verify your address and activate your account.

When you first log in, you will be prompted to name your workspace. This is the organisational container for your team — think of it as your company or department name.

You can change the workspace name and settings at any time from the Admin dashboard.

Custos AI works on a BYOK (Bring Your Own Key) model. You need at least one API key from a supported LLM provider to start chatting. Go to Settings → API Keys and add your first key.

Supported providers: OpenAI, Anthropic, Google (Gemini) and Mistral.

See the BYOK guide for step-by-step instructions per provider.

Before inviting your team, we strongly recommend setting a monthly budget limit. This prevents unexpected LLM costs if usage spikes.

Go to Settings → Budget and set a workspace-level monthly limit. You can also set per-user limits later. See the Budget limits guide.

Go to Settings → Team and click Invite member. Enter their email address and choose a role:

The invited user receives an email with a link to create their account and will automatically join your workspace.

Go to the Chat interface and select a model from the dropdown at the top. Choose from any provider whose API key you have connected.

Type your message and press Enter. Your request is routed to the LLM provider via your API key. Custos AI never stores your message content — it passes directly from the provider to your browser.