Guide · AI keys
Set up your own AI key
DampApp Pro's AI tools, such as AI Polish, photo analysis and the executive summary, work straight away through our shared AI service, but only up to a daily limit.
We recommend every Pro user adds their own key from Google Gemini or OpenAI. Our daily limit then no longer applies, the AI tools are there whenever you need them, and you pay the AI company directly for what you use: usually a cent or two per AI action.
Checked against the providers' own pages on 22 September 2026.
- Who is it for?
- Every Pro user. It is the best way to use the AI tools, with no daily limit.
- What it costs
- A cent or two per AI action, paid to Google or OpenAI. A busy month is typically a few US dollars.
- You will need
- A payment card, about 15 minutes, and DampApp Pro Pro.
- Can I cap it?
- Yes. Both guides set a spending limit, so you can never be surprised by a bill.
Why add your own key?
We recommend it for everyone on Pro. The AI tools work without one, but only through our shared service, which has a daily limit. Your own key gives you:
- no daily limit, so you never see “Daily AI Limit Reached” in the middle of a survey;
- AI Polish and photo analysis on every survey, all day, at a cent or two per use;
- your own account with the AI company, with your own spending cap and a clear record of what you used.
The key boxes are part of Pro
They are in SettingsIntegrations, which is a Pro tab. On Free you get a few AI uses of each tool every month instead. The limit message mentions adding a key; that step needs Pro.
What is an API key?
An API key is a long password that lets an app use your account with an AI company. When you paste your key into DampApp Pro, the app sends your AI requests to Google or OpenAI on your account, and they bill you for them.
Because anyone holding the key can spend your credit, treat it like a bank card PIN. See Keep your key safe.
A chat subscription is not an API key
Paying for ChatGPT Plus, or a Google AI plan for the Gemini app, does not give you an API key or credit. The key comes from each company's developer site and is billed separately.
Why you now need billing
Older advice, including ours, said a Gemini key would cost you nothing. That is no longer practical:
- Google Gemini: Google cut its free allowance sharply in December 2025. Without billing, a key now stops after a handful of AI actions a day, and outside the UK, EEA and Switzerland Google may use what you send to improve its products. With billing on, it does not.
- OpenAI: there is no free allowance. The key only works once you have bought credit.
The good news: both let you pay in advance. You buy a small amount of credit (from US$5), and when it runs out the AI simply stops until you top up. That is the simplest way to stay in control.
Gemini or OpenAI?
Both work well for survey wording and photos. The differences are in the setting up:
| What differs | Google Gemini | OpenAI |
|---|---|---|
| Where you set it up | Google AI Studio (opens in a new tab) | platform.openai.com (opens in a new tab) |
| Paying | Prepaid credit from US$5 for most new accounts, plus VAT in the UK | Prepaid credit from US$5 |
| Spending limit | Your credit balance, plus a monthly spend cap | Your credit balance, plus a hard monthly limit |
| Rough cost per AI action | About half a cent to 2 US cents | Under 1 US cent |
| Your data | With billing on, not used to improve Google's products | Not used for training unless you opt in |
| Set-up effort | A little more: Google's billing pages have more steps | Simpler |
Our suggestion
Choose Gemini if you have a Google account and want your reports to read the way they do now: the app's built-in AI uses Gemini too.
Choose OpenAI if you find Google's billing pages confusing, or you already have an OpenAI account. It is the quickest to set up.
You can save a key for each and switch between them at any time under “AI Provider”.
The step-by-step guides
Each guide takes about 15 minutes, with a big button that opens the exact page you need, and pictures of where to paste the key in the app.
How to never get a surprise bill
Both guides set up three layers of protection. Together they mean you can never spend more than you chose:
- Prepaid credit. Buy a small amount, such as US$5 or US$10. When it runs out, the AI stops. Nothing more is charged.
- Automatic top-up switched off. Both companies can refill your credit automatically. Leave that off (OpenAI turns it on by default, so the guide shows you where to switch it off).
- A monthly limit. Set a monthly cap, for example US$10. If you ever do hit it, the AI stops until the next month or until you raise it.
You can check what you have spent at any time: Gemini spend (opens in a new tab) · OpenAI usage (opens in a new tab).
If your credit runs out in the middle of a survey, only the AI buttons stop. Everything else in the app carries on, and you can type the wording yourself.
Keep your key safe
- Paste it only into the app. Do not email it, text it or post it anywhere.
- DampApp Pro support will never ask for your key.
- When you tap “Save & Sync Settings” while signed in, the key is saved to your secure cloud profile, so your other devices get it too.
- If you think someone else has it, delete it on the provider's keys page and create a new one. The old key stops working straight away.
Messages you might see
| What you see | What it means | What to do |
|---|---|---|
| “AI Limit Reached” | You are on Free and have used this month's free uses of that tool. | Wait for the 1st of the month, or upgrade to Pro. |
| “Daily AI Limit Reached” | You have used today's allowance on our built-in AI. | Try again tomorrow, or add your own key using the guides above. |
| “API Rate Limit Exceeded” | Your own key has run out of credit, reached its monthly limit, or is on Google's tiny free allowance. | Wait a minute and try again, then check your credit and limit using your provider's guide. |
| “API Key required. Check Settings.” | The key was not accepted. It may have been pasted with a space, or deleted. | Copy it again, paste it in SettingsIntegrations and tap Save & Sync Settings. |
| “Our free AI service is temporarily at capacity” | Our built-in AI is busy. Nothing was used up. | Try again in a few minutes. |
Questions people ask
Does my Pro subscription include AI credit?
Pro includes daily use of our built-in AI. If you add your own key, that usage is billed by Google or OpenAI instead, and our daily limit no longer applies.
Do I need to add the key on every device?
Not if you are signed in. “Save & Sync Settings” stores it in your cloud profile, and your other devices pick it up. Otherwise, paste it on each device.
What gets sent to Google or OpenAI?
Only what each tool needs: the note you polish, the photos you analyse or, for the executive summary, the client name, address and findings. With billing on, neither company uses it to train its AI.
Can I go back to the built-in AI?
Yes. Clear the key box, tap “Save & Sync Settings”, and the app goes back to the built-in AI and its daily limit.
Official help from the provider
These are the provider's own pages. They are the final word if anything here looks different on your screen, because providers change their websites from time to time.
- Google AI Studio: API keys (opens in a new tab)
- Google: Gemini API billing (opens in a new tab)
- Google: Gemini API pricing (opens in a new tab)
- Google: Gemini API rate limits (opens in a new tab)
- OpenAI: prepaid billing explained (opens in a new tab)
- OpenAI: ChatGPT and API billing are separate (opens in a new tab)
- OpenAI: API pricing (opens in a new tab)
Related guides
Still stuck?
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