Guide
Bring your own OpenAI key
At launch, v2x Invoice and v2q Invoice use your own OpenAI API key to turn your voice into text and pick out the details. Here's what that means, what it costs, and how to set it up safely in about five minutes.
What “bring your own key” means
OpenAI does the listening: it turns your recording into text and works out the details, such as a customer's name or an item's price. Instead of paying us a subscription for that, you open your own OpenAI account, add a little credit, and paste a key into the app. The app then talks to OpenAI directly, using your key.
Why do it this way? You pay only for what you use, with no subscription and no middleman. Your recordings go straight from your phone to OpenAI and never pass through us.
What it costs
A typical invoice
about 1p
A new customer
under ½p
100 invoices a month
about £1
OpenAI charges by the minute of audio and by the amount of text it reads, so short recordings cost very little. A few pounds of credit lasts most people months. OpenAI bills in US dollars, so your bank may add a small conversion fee.
A ChatGPT subscription such as ChatGPT Plus is a separate product. It doesn't include API credit, and you don't need one.
Set it up
- Create an OpenAI account Go to platform.openai.com and sign up, or sign in. Your ChatGPT login works here too.
- Add prepaid credit Go to Settings → Billing, add a payment method, then add credit. The smallest amount OpenAI allows is plenty to start.
- Turn off auto-recharge Still in Billing, make sure auto-recharge is off. Then you can never be charged more than the credit you've added.
- Create a key Go to API keys and create a new secret key. Give it a name you'll recognise, such as “v2x Invoice on my iPhone”, and copy it. OpenAI shows the full key only once.
- Paste it into the app Open the app, paste the key and tap Validate. The app checks it with OpenAI once, then keeps it in your iPhone's Keychain.
Tip: do steps 4 and 5 on your iPhone. Sign in to platform.openai.com in Safari, create the key, and paste it straight into the app. That way you never have to type it out.
Stay in control of spending
- Prepaid credit with auto-recharge off is a hard limit. When the credit runs out, the app tells you and stops. Nothing more is charged.
- See what you've spent on OpenAI's usage page, day by day.
- Set alerts. OpenAI's settings also let you set a monthly budget and email alerts for your project.
- One key per app (for example one for v2x and one for v2q) makes it easy to see what each one uses, and to turn one off without affecting the other.
Keep your key safe
- Treat it like a password. Anyone who has it can spend your credit.
- The app keeps it in your iPhone's Keychain and sends it only to OpenAI. We never receive it.
- We will never ask for your key. Don't email it to anyone, including us. If you need help, tell us the message the app shows.
- Lost your phone, or think the key has leaked? Delete it on the API keys page. It stops working straight away. Then create a new one.
- To remove it from the app, go to Settings → Disconnect everything.
If something goes wrong
“Your OpenAI account has no credit left.”
Add credit under Settings → Billing at platform.openai.com, then record again.
“OpenAI is busy right now.”
A temporary limit at OpenAI. Wait a few seconds and try again.
The key won't validate
Check you copied the whole key, which starts with sk-, with no spaces before or after it. Also check that your account has credit. New accounts with no credit can't use the API.
The app asks for your key again
OpenAI rejected the saved key, usually because it was deleted or replaced. Create a new key and paste it in.
For every message the app can show, see v2x Invoice help and support.
Questions
Can I use the same key in both apps, or on two phones?
Yes. Separate keys make it easier to see what each one uses and to turn one off, but one key works fine.
Does OpenAI use my recordings to train its models?
At the time of writing, OpenAI says data sent through its API isn't used to train its models by default. It keeps it for up to 30 days for abuse monitoring, unless the law requires longer. See OpenAI's policies.
Can you see my key, recordings or invoices?
No. There's no server of ours in between: the app talks only to OpenAI and to your accounting software. See the v2x privacy policy.
Will I always need my own key?
No. Subscription plans that need no OpenAI account are on the way. See plans.