Bring Your Own Key: API Key Setup

Guide 1 of 3

Getting an API key for your AI provider

How to create an API key and set up billing with OpenAI, Claude or Gemini, for use on the LangLime BYOK plan.

OpenAI

First, you’ll need to create an OpenAI account, if you don’t already have one.
Once you have an account, head to the API keys page of the OpenAI platform and click on the green button that says “Create new secret key”.
You’ll be greeted with a popup that looks something like this:

Creating an OpenAI API key
You can leave most of the settings as default, but just be sure to create a name for the key. Copy this key and store it somewhere safe.
Here comes the fun part... paying. Click on your profile icon in the top right of the screen, and head to “Your profile”. From here, you can then click on the “Billing” tab in the left bar. Or just follow this link.
From here, click on that scary “Add payment details” button and fill out the form.

So. Now you have a funded OpenAI account and a working API key. You can come back to this platform when you need to top up your credits, or check your usage stats.

Claude

You’ll have to sign up to the Claude platform if you haven’t yet got an account, and complete the welcome flow.
These guys aren’t messing around. They want you to enter your card details straight away. Hmmmm... let’s humour them. Click on the “Buy credits” button and fill out the form.
Once you’re through this paywall, you can finally get to the API keys page by following this link, or by clicking on the key icon in the left bar.
Click on the button that says “Create Key”, and give your new friend a name:

Creating a Claude API key
Keep hold of this key, and you’re all ready to go :)

Like with OpenAI, the Claude platform lets you top up your credits and check out your usage.

Gemini

I’m sure you’ve got a Google account already, so just go ahead and log in to Google’s AI Studio.
Click on the button near the top of the screen that says “Get API key”, which will take you to the API key page... obviously.
This page has another button, this time saying “Create API key”. If you’ve ever used Google’s Cloud Platform, you can assign your key to a certain project, or you can just leave it blank. Copy that bad boy, and now it’s time to worry about billing.
On this same page, near the bottom, you should see your new key appear. Clicking on the link (shown with the red arrow) will take you to the billing page.

Gemini billing link
Follow the instructions to fund your API key, and voila. Like the other two AI providers, you can view your usage on this page.

Guide 2 of 3

Adding or changing your API key

Add your API key when you first set up BYOK, or change it later on the AI Models page. I check each key before you can use it.

Selecting your first provider

When you first sign up and enter the app, you’ll be asked to choose an AI provider and input the relevant key. I’ll check that the key is valid and your account is funded, and then you can continue to use the app.

BYOK welcome step — Choosing your initial AI provider

Changing your key

If, for whatever reason, you want to change the key for your chosen AI provider, you can do so in the AI Models page. You can also find this page in the dropdown menu when clicking on the user icon in the top right of the screen.

Guide 3 of 3

Choosing your AI provider and model

Switch between providers you have a valid key for, and pick the model each one uses, on the AI Models page.

Changing your AI provider

From the AI Models page, you can add new providers. After adding one, you’ll have to enter a valid AI key before it can be used. Once an API key for a provider has been validated (as shown with a blue indicator ), it can then be used inside the app by selecting it from the dropdown in the top half of the page. Your active AI provider is indicated with a green dot .

Changing your AI model

Each provider has a list of available models, which you can also select from a dropdown menu near the top of the screen. I suggest that you do a quick bit of research on the models before you select them, as some are more expensive to use than others.

Recommended providers and models

The provider I recommend is indicated by Recommended, and each provider also has a Recommended model which indicates the recommended model for this specific provider. Of course, you don’t have to take my word for it... try whatever you like :)