Using OpenRouter

1. What is OpenRouter?

OpenRouter is an AI model aggregator that provides access to 400+ models from providers like Meta, Google, Mistral, and others through a single, unified API. It is one of the easiest ways to get started with the Cataloging Assistant because:

• Free tier available — Several high-quality models are available at no cost
• No credit card required — Sign up and start using free models immediately
• Single API key — One key gives you access to all available models
• Pay-as-you-go — When you're ready, add credits for access to premium models

OpenRouter homepage

2. Create an Account

Creating an OpenRouter account is quick and free:

1. Visit openrouter.ai
2. Click "Sign In" in the top-right corner
3. Choose your sign-in method: Google, GitHub, or email
4. Complete the sign-up process and verify your email if prompted

OpenRouter sign-in page — Google, GitHub, or email

3. Get Your API Key

Once signed in, generate an API key:

1. Click your avatar in the top-right corner and go to Settings
2. Navigate to the API Keys section
3. Click "Create Key"
4. Give your key a name (e.g., "LCSH Cataloging")
5. Copy the key immediately — it will only be shown once

4. Find Free Models

OpenRouter offers several free models that work well for LCSH cataloging:

To browse all free models, visit the OpenRouter models page and filter by "free".

OpenRouter models page — filter by "free" to find no-cost options

5. Configure the Cataloging Assistant

With your API key ready, configure the Cataloging Assistant:

1. Open the Cataloging Assistant
2. Go to Settings (gear icon in the navigation)
3. Under Cloud Providers, select "OpenRouter" from the Provider dropdown
4. The model list will load automatically — use the search box to find your preferred model
5. Scroll down to API Keys and paste your OpenRouter API key
6. Click "Test Connection" to verify everything works

Cataloging Assistant settings — OpenRouter selected with model picker

6. Using Free Model IDs

OpenRouter uses a naming convention for free model variants:

When you select a model from the model picker in the Cataloging Assistant, it will automatically include the correct model ID. If entering a model ID manually, make sure to include the :free suffix to use the free version.

7. Rate Limits & Tips

Keep these limits and tips in mind when using OpenRouter:

Tips for Best Results

• Start with DeepSeek R1 (free) — it has strong reasoning capabilities that work well for subject analysis and LCSH selection
• Use Gemini 2.5 Flash (free) for images — if you need to analyze book covers or title pages, this model supports vision
• Monitor your usage — check your usage on the Activity page
• Add credits for higher limits — even $5 in credits significantly increases your rate limits and unlocks paid models
• Try different models — different models may perform better for different types of materials (fiction vs. non-fiction, technical vs. humanities)