Curos

Getting started

Updated June 1, 2026

Ichnus is the free AI assistant from Curos, a non-profit AI research organization. This guide walks you through creating an account, choosing a model tier, reviewing your privacy defaults, and getting the most out of your first conversations.

Signing in

  • Go to the Ichnus app and choose “Create account.” You can sign up with an email address or a supported sign-in provider.
  • Verify your email address. Most accounts are active within a few minutes.
  • Sign in on the web, desktop, or mobile app. Conversations sync across devices when you are signed in.

If you have trouble signing in, see the Help center.

Choosing a model tier

Ichnus offers three models in the Krus, Mantus, and Corus family:

  • Krus: the fastest model, best for short answers and everyday tasks. 128,000-token context.
  • Mantus: the balanced default. Good for most work, with a 256,000-token context.
  • Corus: the frontier model with a 1,000,000-token context. Free to use within fair-use limits.

You can switch models per conversation from the model selector. Mantus is the default. For most tasks you do not need to change it. Choose Krus when speed matters, and Corus when you are working with very long documents or complex reasoning problems.

Privacy defaults

Curos is funded by foundations, individual donations, and government grants, not by advertising or selling data. Your defaults reflect that:

  • Conversations are not used to train Curos models unless you opt in. By default they are not.
  • Chat history is retained for 30 days so you can pick up where you left off, then deleted. You can shorten or extend this window in Settings.
  • You can turn on incognito-style sessions that store nothing after the conversation ends.

You can review and change these at any time in Settings under Privacy. See the Privacy page for the full policy.

Tips for your first conversations

  • Be specific. Give the model context: what you are trying to do, who it is for, and any constraints.
  • Use the honesty features. If the model is unsure, it can tell you instead of guessing. You can ask it to mark uncertain statements.
  • Use attachments for long documents with Corus. Paste a link or attach a file and ask questions against the full text.
  • Save prompts you reuse. The prompt library lets you keep common prompts and share them with teammates or classrooms.
  • Start small with Krus for quick drafts, then move to Mantus or Corus for revision and deeper analysis.

Where to go next

  • Models and tiers for a full comparison of context windows and fair-use limits.
  • Safety and evaluation for how Curos tests its models before release.
  • API reference if you want to build with the Ichnus API.
  • Community to join the Community Council or participate in model feedback.

Need help? The Help center answers common questions, and you can reach support from the app’s help menu.

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