The AI writing tools in the Manuscript Editor work on a Bring Your Own Key (BYOK) basis: you add an API key from an AI provider, and Writing Crucible uses it to make AI requests for you. You pay your provider directly for what you use.
Which features need a key
Need your own key: Continue writing, Continue writing with guidance, and the AI editing tools (Clarity, Tighten, Lengthen, Show, Active, Dialogue). These are part of the Professional plan.
Don't need a key: worldbuilding AI Summaries and the Cruci support chat run on Writing Crucible's own AI.
Supported providers
OpenAI
Google Gemini
Anthropic (Claude)
OpenRouter: one OpenRouter key also gives you access to many OpenAI, Anthropic and Google models.
You can save more than one key and switch between models from the Model picker in the editor's / menu. The picker only lists models your saved keys can run.
Adding a key
Go to Settings → AI Providers and click Add New Key.
Choose the Provider (openai, gemini, claude or openrouter).
Paste your API Key and give it a Nickname so you can tell your keys apart. Both are required.
Click Save Key.
The key is ready to use straight away.
Managing your keys
From Settings → AI Providers you can Reveal a key (they're masked by default) and Hide it again, Edit its nickname or replace its value, or Delete it.
How your keys are protected
Keys are encrypted at rest.
Keys are masked until you choose to reveal them.
Writing Crucible staff cannot view or decrypt your API keys.
Keys are never logged, shared with other users or collaborators, or included in exported files.
Every key action (save, edit, reveal, delete) requires you to be signed in.
Your keys are used only for your own AI requests, and Writing Crucible doesn't train AI models on your writing.
Getting a key
OpenAI: platform.openai.com/api-keys
Google Gemini: aistudio.google.com/apikey
Anthropic: console.anthropic.com
OpenRouter: openrouter.ai/keys
Troubleshooting
"API Key is required" or "Nickname is required"
Fill in both fields before saving.
My key is hidden after saving
That's expected. Keys are masked by default; click Reveal to see it.
AI features aren't working
Check that you're on the Professional plan or the free trial.
If the Model picker in the / menu shows No model available, none of your saved keys can run a model. Add a key under Settings → AI Providers.
Check that your provider account has credit available.
Good practice
Use a separate key just for Writing Crucible.
Rotate keys now and then, and delete ones you no longer use.