How do I turn on AI and connect a provider?

AI is off until you choose it. This shows where to switch it on, how to connect your own key, a ChatGPT plan or a model on your own computer, and what you agree to first.

Before you start

If you want a cloud provider: an API key from Anthropic, OpenAI, Google, xAI or OpenRouter, or a ChatGPT plan. Each Get a key link opens the provider's site.
If you would rather nothing leaves your computer: Ollama or LM Studio installed and running.

Steps

Click the gear at the bottom of the activity bar and choose App Settings.
App Settings holds the settings for every book on this computer.
Open the AI tab. While AI assistance is Off, no AI controls appear and nothing you write is sent to an AI service.
AI stays off until you switch it on.
Switch AI assistance on. Until you connect a provider, AI actions say Set up an AI provider and nothing can be sent.
To use a cloud provider, find its row under AI API keys, paste your key and press Save.
Keys stay on this computer. On a Mac they go in Keychain.
The first time, Before you connect an AI provider opens. Read which providers may train on your writing and what PugWriter sends. Then tick the box and press Agree & save key, or press Cancel to save nothing.
Nothing is saved until you agree.
To use a ChatGPT plan instead of a key, press Connect ChatGPT under ChatGPT Subscription. Usage counts against your plan's limits rather than being billed per word.
To keep everything on your computer, switch on Ollama or LM Studio under Local AI servers. Prompts go only to that address, and no key is needed.
A local model costs nothing to run.
Under Default models, press Recommended on a row, or pick a model for each level: Utility, Workhorse, Flagship, Frontier and Creative. Cheaper levels cost less per request.
Each AI feature uses one of these levels.

Click a screenshot to see it larger, then use the arrow keys to step through them.

Check it worked

Select a sentence in a chapter and press ⌘J / Ctrl+J. The AI bar offers Proofread and Custom….
Before a provider is connected, the AI ribbon (⌥⌘. / Ctrl+Alt+.) shows Set up an AI provider under each action.

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