Use this guide to choose AI models in CoAuthor settings, understand which models are available, and know what happens after you save a model preference.
What AI model settings do
CoAuthor uses included platform credits first. In AI settings, you can add your own provider keys and choose which models CoAuthor should use after those included credits are exhausted.
You can choose model preferences for:
- Planning
- Writing
- Image generation
- Deep research
Planning is used for orchestration work such as topic development, outlines, research plans, and workflow planning. Writing is used for draft generation, editing assistance, and related writing work.
Before you start
You’ll need:
- access to CoAuthor
- an API key for any provider you want to use after included credits are exhausted
- access to Settings > AI in CoAuthor
Supported provider keys are:
- Anthropic
- OpenAI
- Gemini
Do not paste API keys into chat or support messages. Add provider keys only in CoAuthor AI settings.
Step 1: Open AI settings
- Open CoAuthor.
- Go to Settings.
- Open the AI tab.
You can also open AI settings directly:
https://tools.clickminded.com/coauthor/settings/aiStep 2: Add provider keys
In the Model providers section, each provider shows whether it is configured.
To add a key:
- Find the provider you want to use.
- Paste the API key into the API key field.
- Click Save.
CoAuthor checks the key before saving it. If the key is valid, the provider status changes to valid.
Step 3: Choose model preferences
In Model preferences, choose the model you want for each available capability.
The visible preferences are:
- Planning
- Writing
- Image generation
- Deep research
Models from providers without a valid key show as unavailable until you add that provider key.
When you choose a model, CoAuthor saves the preference automatically and shows Model preferences saved.
Available planning and writing models
The current planning and writing model options are:
| Provider | Model |
|---|---|
| Anthropic | Claude Sonnet 4.6 |
| Anthropic | Claude Opus 4.8 |
| OpenAI | GPT-5.5 |
| OpenAI | GPT-5.4 |
| Gemini | Gemini 3.5 Flash |
CoAuthor can use these models for both Planning and Writing.
Other available model preferences
Deep research:
- OpenAI Deep Research
Image generation:
- Gemini image preview
- GPT Image 2
Choosing an Image generation model also applies the same preference to image editing.
Default model preferences
If you have not changed your model preferences, CoAuthor uses the current defaults:
| Capability | Default model |
|---|---|
| Planning | Claude Sonnet 4.6 |
| Writing | Claude Sonnet 4.6 |
| Deep research | OpenAI Deep Research |
CoAuthor keeps routing defaults up to date as supported model IDs change. Existing saved preferences for older models are moved to the refreshed model lineup where possible.
What happens after you save a preference
After you save a model preference:
- future CoAuthor work uses included platform credits first
- after included credits are exhausted, CoAuthor uses your selected model with your valid provider key
- models from providers without valid keys stay unavailable in the dropdown
- CoAuthor validates that the selected model supports the selected capability
- image generation preferences also update image editing preferences
Troubleshooting
A model is listed, but you cannot select it
This usually means the provider key has not been added or is not valid.
Go to:
Settings > AI
Then add or update the provider key for Anthropic, OpenAI, or Gemini.
A provider says Not configured
Add that provider’s API key in the Model providers section and click Save.
If the key is accepted, the provider status changes to valid.
CoAuthor asks for a provider key during generation
This can happen when included credits are exhausted and CoAuthor needs your own provider key to continue.
Open Settings > AI, add the required provider key, then retry or resume the generation.
Frequently asked questions
Do I need to add API keys to use CoAuthor?
Not immediately. Included credits use CoAuthor platform keys first. Add your own provider keys in AI settings when you want CoAuthor to continue using your selected models after included credits are exhausted.
Can Planning and Writing use different models?
Yes. Planning and Writing are separate preferences, so you can choose one model for planning work and another model for writing work.
Can I select a model without adding that provider’s key?
No. The settings page marks models from providers without a valid key as unavailable. Add the provider key first, then choose the model.
Need help?
If you run into issues, contact support:
- Support: send us an email at [email protected]
- AI settings: https://tools.clickminded.com/coauthor/settings/ai