# Use OpenAI

> Get an OpenAI API key, connect it to Resurf, and know what to check when the connection test fails.

- Page: https://resurf.so/guides/use-openai
- Section: AI
- Works on: Mac, iPhone, iPad
- Last checked against the app: 2026-10-19
- Key from: platform.openai.com
- Looks like: sk-…
- Syncs: Yes, through iCloud Keychain

## Get a key

You need an OpenAI API account, which is separate from ChatGPT.

1. Sign in at [platform.openai.com](https://platform.openai.com/api-keys) and open **API keys**.
2. Create a key, then copy it. It starts with `sk-` and is shown in full only once.
3. Add credit before you connect. OpenAI bills the API in advance: you buy credit on the **Billing** page, and requests fail with a billing error once it runs out.

On iPhone and iPad, the **Create a key at platform.openai.com** link on the key step opens the same page.

## Connect it

On Mac:

1. Choose **Settings…** (`⌘,`) and click **Providers** in the sidebar.
2. Click **Connect** beside **OpenAI**.
3. Paste your key into **API key** and click **Connect**. Resurf sends one test request to check it.
4. OpenAI moves to the top and shows **Connected**.

On iPhone and iPad:

1. In Resurf's Settings, turn on **AI**, or tap **Providers** if AI is already on.
2. Tap **OpenAI**, paste your key and tap **Continue**.
3. Resurf checks the key. Then read what will be shared and tap **Allow**.

![Settings, Providers pane: OpenAI and Gemini connected; Claude, OpenRouter and Ollama to connect.](https://resurf.so/guides/shots/settings-providers@2x.webp)

Your first provider turns on **AI features** and **Suggest as you capture**. The test sends your key and asks OpenAI for its model list. No capture content is in it.

## What it powers in Resurf

Resurf picks an OpenAI model for you when you connect. It writes [suggestions](https://resurf.so/guides/ai-suggestions) as you capture (titles, tags, spaces and summaries), voice note titles and clean-ups, generated notes, and answers in the [Assistant](https://resurf.so/guides/ask-ai) on Mac. If the model you pick can't see images, Resurf reads them with a vision model from OpenAI, or organizes them from their text.

- **Cloud voice transcription.** OpenAI is the only provider for it. Choose **Cloud** in [Settings → Voice](https://resurf.so/guides/voice-ai) and audio goes to OpenAI.
- **The only key that syncs.** Resurf keeps a copy in iCloud Keychain, so your other devices can connect OpenAI without pasting the key again. On iPhone and iPad you still tap **Allow** once on each device.

## When the connection test fails

On Mac you see **Could not connect to OpenAI. Check the API key and try again.** On iPhone and iPad the test step says **The key didn't work.**, with **Back** and **Try again**.

| Likely cause | What to do |
| --- | --- |
| The key is wrong | A character is missing from the paste, or the key was deleted on OpenAI's side. Make a new key and paste the whole thing. |
| No credit | A new OpenAI account has none until you buy some on the Billing page. The test may pass and suggestions still fail with a billing error. |
| Credit ran out | OpenAI's error says the credit balance is exhausted. Top up on the Billing page, then allow a few minutes before you test again. |

On Mac, click **Manage** beside OpenAI and click **Test** to run the check again.

## Questions

### Does a ChatGPT subscription come with API access?

No. The API is a separate account with its own credit. Buy credit on platform.openai.com before you connect.

### Do I have to paste the key on every device?

Not for OpenAI. Its key syncs through iCloud Keychain. On iPhone and iPad you still tap Allow once on each device.

### Can I transcribe voice notes with OpenAI?

Yes. Choose Cloud under Transcribe with in Settings → Voice. Cloud transcription is OpenAI only.

## More guides

- Previous: [AI providers](https://resurf.so/guides/ai-providers.md)
- Next: [Use Claude](https://resurf.so/guides/use-claude.md)
- [AI providers](https://resurf.so/guides/ai-providers.md): Connect your own AI provider with your own key. Resurf's AI features stay off until you do.
- [Use Claude](https://resurf.so/guides/use-claude.md): Get an Anthropic API key, connect it to Resurf, and know what to check when the connection test fails.
- [Use Gemini](https://resurf.so/guides/use-gemini.md): Get a Gemini API key from Google AI Studio, connect it to Resurf, and know what to check when the connection test fails.
- [Use OpenRouter](https://resurf.so/guides/use-openrouter.md): Get an OpenRouter key that reaches many models, connect it to Resurf, and know what to check when the connection test fails.
- [Run Ollama on your Mac](https://resurf.so/guides/ollama.md): Run models on your own Mac with Ollama, with no key and nothing sent to the cloud.
- [AI suggestions](https://resurf.so/guides/ai-suggestions.md): When you save something, your AI provider writes a title, a summary and keywords for it, and suggests spaces.
- [Model and instructions](https://resurf.so/guides/ai-model.md): Pick the model that writes your suggestions, give it your own instructions, and run it again over your library.
- [Assistant](https://resurf.so/guides/ask-ai.md): Ask questions about your library in a chat pane on Mac, and get answers that cite the captures they used.
- [Voice notes and AI](https://resurf.so/guides/voice-ai.md): Transcribe voice notes on your device or with OpenAI, and let your model title them, tidy the transcript and write notes.
- [What AI sends](https://resurf.so/guides/ai-privacy.md): What each AI feature sends to your provider, and when nothing is sent at all.
- [Every guide](https://resurf.so/llms.txt)